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Building Geometrical Constructions in CubeCAD

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/* Generating and Controlling the Mesh */
[[Image:Splash-cad.jpg|right|800px720px]]<strong><font color="#655234" size="4">An Intuitive 3D Parametric CAD Modeler Shared By All [[EM.Cube]] Computational Modules</font></strong>
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[[Image:Back_icon.png|40px30px]] '''[[EM.Cube | Back to EM.Cube Main Page]]'''
== CubeCAD in a Nutshell ==
CubeCAD is a comprehensive, parametric, 3D CAD modeler along modeling environment equipped with integrated mesh generation, data processing and visualization capabilities and a powerful Python scripting environmentinterpreter. A highly streamlined visual interface literally puts all of CubeCAD's features at your fingertips. With the click of buttons, you can build complex 3D models and structures in seconds using a large variety of intuitive mouse-based object creation and transformation tools. Import and export of standard CAD formats allow for native construction of complex geometries along with the ability to fly in external CAD models with utmost ease. CubeCAD also features an extensive library of mathematical functions that can be used for construction of new geometries and data or post-processing of existing data. CubeCAD allows you to visualize simulated, measured or imported 3D data in a variety of formats and overlay them on your CAD structures.
All of [[EM.Cube]]'s computational modules use CubeCAD together with individually customized navigation trees as their graphical user interface and geometry definition utility. Learning CubeCAD is therefore the gateway to stepping stone for learning all the other modules. Once you have mastered the basics of CubeCAD, using the other modules will be very straightforward.
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[[Image:cad_manual-25_tn.jpg|thumb|left|640px|An example of a complex CAD geometric structure in CubeCAD.]]
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Native Solids: Box, cylinder, cone, pyramid, sphere, ellipsoid, torus, and polymesh solids (generalized polyhedra)</li>
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Native Surfaces: Rectangular strip (or loop), circle strip (or ring), radial strip, ellipse strip, spiral strip, triangle strip, taper strip (with exponential transition), regular polygon, polystrip, NURBS strip, polymesh surfaces, equation-based, grid-based and data-file-based parametric surfaces</li>
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Native Curves: line, polyline, NURBS curve, circle, super-quadratic curve, parabola, hyperbola, spiral curve, helix, and equation-based Cartesian, polar and parametric curves and grid-based and data-file-based curves</li>
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Easy mouse-based object creation and real-time editing with preview</li>
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Translate, rotate, scale, mirror and link operations</li>
Fillet sharp corners and polylines</li>
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Sweep curves into strips, pipes or rail curve and surfaces along other curves</li>
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Fill closed curves to create planar objects</li>
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Merge or sew curves</li>
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Roughen surfaces and solids with specified statistics</li>
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Create random clouds of a given key object within a specified container object</li>
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Fractal trees with random pruning</li>
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Adaptive grid with local view rotation</li>
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Define variables to relate and control CAD geometric object properties</li>
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Constrained variables with arbitrary mathematical expressions including random variablesand Python functions</li>
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Continuous, discrete or mixed parametric spaces</li>
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Dynamic update and parametric editing</li>
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Dry runs for sanity check</li>
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Object links with arbitrary local offsets and rotation angles</li>
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Object connections with persistent local coordinate systems</li>
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Multiple dependency link chains</li>
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Shapefile import</li>
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DXF import/export</li> <li> FACET file import/export for triangular surface mesh</li>
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Mesh data Whole or partial geometry import/exportusing Python scripts</li>
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Hundreds of mathematical functions for data processing</li>
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User defined Python functions and expressionsscripts</li>
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Statistical analysis of data</li>
Differentiation, integration, discrete Fourier transform and linear regression of data</li>
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Data generator utility for creation of 3D data of Cartesian, spherical and mesh typesdata</li>
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2D complex uniform and non-uniform data planes with magnitude, phase and 3D vector plots</li>
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3D complex polar/spherical angular data patterns</li>
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Vectorial data surfaces and planes with individual X, Y, Z and total plots</li>
Extensive graphing capability (Cartesian, polar, Smith chart, bar chart, polar stem chart, etc.) with dynamic editing</li>
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[[Image:Apache1.png|thumb|left|360px|An Apache helicopter.]]
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[[Image:CAD_Apache_new.png|thumb|left|360px|The imported model of the Apache helicopter.]]
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== Constructing Physical Structures Using Standard Geometric Objects ==
===The Variety of EM.Cube's Native Object Types===
In [[EM.Cube]], objects are generally categorized into four types: solids, surfaces, curves and points. A Point is a dimensionless object that is represented by a set of coordinates (x,y,z). Curves are one-dimensional special objects, whose length can be measured. The simplest curve object is a (straight) line. Surfaces are two-dimensional objects whose surface area can be measured. A surface is usually characterized by a number of edges that enclose the object's area. The edges meet at vertices or nodes. The simplest surface object is a rectangle strip, which has four edges and four vertices. Solids are three-dimensional objects whose volume can be measured. A solid is usually characterized by a number of faces that enclose the object's volume. Faces meet at edges and edges meet at vertices or nodes. The simplest solid object is a box, which has six faces, twelve edges and eight vertices. In addition to the specific standard object types, there are generic curve objects, generic surface objects and generic solid objects. Most external CAD objects are imported as objects of the generic type.
In view of the drawing process and geometrical properties*Curves are one-dimensional objects, objects whose length can also be divided into two groups: '''Dimensional''' objects and '''Nodal''' objectsmeasured. A dimensional The simplest curve object is characterized by a local coordinate system (a center and local X-straight) line. Other curve objects include circle, Ysuper- quadratic curve, parabola, hyperbola, spiral curve, helix, polyline and ZNURBS curve. [[EM.Cube]] also provides a generalize curve generator. *Surfaces are two-axes) and dimensional objects whose surface area can be measured. A surface is usually characterized by a number of dimensional parameters such as lengthedges that enclose the object's area. The edges meet at vertices or nodes. The simplest surface object is a rectangle strip, width, height, radius, etcwhich has four edges and four vertices. Examples of dimensional Other surface objects are boxinclude circle strip, sphereradial strip, rectangular ellipse strip, linetaper strip, helixregular polygon, etcspiral strip, polystrip and NURBS curve. [[EM.Cube]] also provides a diverse list of native parameterized generalized surface generator. *Solids are three-dimensional objects in all the three categories of curves, surfaces and solidswhose volume can be measured. A nodal object solid is usually characterized by a set number of points (faces that enclose the object's volume. Faces meet at edges and edges meet at vertices or nodes). The simplest solid object is a box, which has six faces, twelve edges and eight vertices. Other solid objects include cylinder, cone, pyramid, sphere, ellipsoid and taper. [[EM.Cube]]'s nodal objects include Polystripalso provides a Platonic solid generator which includes tetrahedron, Polylinetessellated hexahedron, NURBS Stripoctahedron, NURBS Curve tessellated dodecahedron and Polymesh icosahedron. *[[EM.Cube]] currently offers two special object types: point and fractal tree. A Point is a dimensionless object that is represented by a set of coordinates (X,Y,Z). A fractal tree is a group of recursively scaled self-similar objects.
CubeCAD provides a diverse set In view of [[Standard Objects|standard the drawing process and geometrical properties, objects can also be divided into two groups: dimensional objects and nodal objects]] that are fully parameterized. In addition to the A dimensional object is characterized by a local coordinate system (a center coordinates and rotation angleslocal X-, these objects have Y- and Z-axes) and a variety number of dimensional parameters that such as length, width, height, radius, etc. Examples of dimensional objects are used box, sphere, rectangular strip, line, helix, etc. In addition to set the standard geometric object types, there are generic curve objects, generic surface objects and control their size and geometrical shapegeneric solid objects. More complex Most external CAD objects can be created by editing and combining these basic shapesare imported as objects of generic type. Objects You can be created by clicking on one translate or rotate an object of the object buttons on the '''Object Toolbar''' or from the '''Object &gt; Solid'''generic type, '''Object &gt; Surface''', or '''Object &gt; Curve''' menusbut you cannot changes its size properties. Once an A nodal object tool is selected, left click anywhere on the work plane to draw the object. The following table show characterized by a list set of points (nodes). [[EM.Cube]]'s standard solidnodal objects include polystrip, surface and polyline, NURBS strip, NURBS curve and polymesh objects:.
<table><tr><td> [[Image:CADVAR1_new.png|thumb|left|480px|Property dialog of a dimensional Triangle Strip object.]] </td></tr><tr><td> [[Image:CADVAR2_new.png|thumb|left|480px|Property dialog of a nodal Polystrip object.]] </td></tr></table> === Local Coordinate System === [[EM.Cube]] CubeCAD provides a number diverse set of different coordinate systems. The two most important ones standard geometric objects that are the World Coordinate System (WCS) and the Local Coordinate System (LCS)fully parameterized. Every object has a Local Coordinate System that determines In addition to the location of the object in the world coordinate system center coordinates and its orientation, i.e., its rotation angles with respect to the world principal axes. The center of the local coordinate system is the most important characteristic point of an object. The position of the LCS center varies among different object types. For example, the LCS center of a box is the center of its bottom face, while the LCS center of a sphere is its true geometrical center. The LCS has three local X-, Y-, and Z-axes. For most these objects, these axes line up with the object's natural axes. For example, the local Z-axis of have a cylinder or a cone is always aligned along its geometrical axis. When you draw a new object, its LCS axes are aligned along the principal world axes by default. After you rotate an object, its LCS axes are no longer aligned with the principal world axes. When you start the [[EM.Cube]] application, you will only see the world X- and Y-axes in the Project Workspace. A small trident icon at the lower left corner variety of the workspace also shows the world coordinate system at all times. There dimensional parameters that are many instances when the relative orientation of objects with respect used to one another set and control their positive or negative directions are very importantsize and geometrical shape. In such cases, making the LCS of More complex objects visible would can be very usefulcreated by editing and combining these basic shapes. You Objects can enable the local coordinate system of an object be created by selecting it, right clicking on the surface one of the object or right clicking buttons on its name in the Navigation Tree and selecting '''Show LCSObject Toolbar''' or from the contextual menu. This will display the red'''Object &rarr; Solid''', green and blue local X-'''Object &rarr; Surface''', Y- and Z-axes of the objects in dashed lines. To disable the LCS, select or '''Hide LCSObject &rarr; Curve''' from menus. Once an object tool is selected, left click anywhere on the work plane to draw the contextual menu of that object.
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<td> [[Image:lcs_tn_newCADVAR1_new.png|thumb|left|450px640px|The local Coordinates System (LCS) Property dialog of Basic Shapesa dimensional triangle strip object.]]</td>
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=== General Drawing Rules ===
 
By default, when you draw a new object, its property dialog appears at the lower right corner of main Window, and [[EM.Cube]]'s object edit mode is enabled. This means that you can edit the newly drawn object at this time. After the drawing is completed, the mouse cursor changes to its &quot;Normal&quot; arrow shape. Besides the default &quot;Draw &amp; Edit&quot; mode, [[EM.Cube]] provides another drawing modes called &quot;Persistent Draw&quot;. In this persistent mode, after you complete the drawing of an object, the mouse cursor does not return to &quot;Normal&quot; and stays in the drawing mode. You can continue drawing more objects of the same type as many as you like. Switching the drawing mode is done from the User Preferences Dialog, which can be accessed from '''Edit Preferences...''' In the &quot;Drawing Mode&quot; section of the '''Objects''' tab of this dialog, select the radio button labeled '''Persistent Draw'''. In this mode, you will still see the object's property dialog at the lower left corner of Main Window. You can hide this dialog by unchecking the box labeled '''Display Properties'''.
 
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<td> [[Image:persistentCADVAR2_new.png|thumb|left|300px640px|Changing CubeCAD's drawing mode from the preferences Property dialog.]] </td></tr><tr><td> [[Image:draw_modes_tn.jpg|thumb|left|450px|The various drawing modesof a nodal polystrip object.]]</td>
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===Glossary of Standard Geometric Objects===
[[Image:Info_icon.png|40px]] Learn To learn more about CubeCAD's the standard geometric objects, see the '''[[Glossary of EM.Cube's Standard Geometric Objects | Standard Geometric Objects]]'''.
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=== Local Coordinate System ===
 
[[EM.Cube]] provides a number of different coordinate systems. The two most important ones are the World Coordinate System (WCS) and the Local Coordinate System (LCS). Every object has a Local Coordinate System that determines the location of the object in the world coordinate system and its orientation, <i>i.e.</i>, its rotation angles with respect to the world principal axes. The center of the local coordinate system is the most important characteristic point of an object. The position of the LCS center varies among different object types. For example, the LCS center of a box is the center of its bottom face, while the LCS center of a sphere is its true geometrical center. The LCS has three local X-, Y-, and Z-axes. For most objects, these axes line up with the object's natural axes. For example, the local Z-axis of a cylinder or a cone is always aligned along its geometrical axis. When you draw a new object, its LCS axes are aligned along the principal world axes by default. After you rotate an object, its LCS axes are no longer aligned with the principal world axes.
 
When you start the [[EM.Cube]] application, you will only see the world X- and Y-axes in the Project Workspace. A small trident icon at the lower left corner of the workspace also shows the world coordinate system at all times. There are many instances when the relative orientation of objects with respect to one another and their positive or negative directions are very important. In such cases, making the LCS of objects visible would be very useful. You can enable the local coordinate system of an object by selecting it, right clicking on the surface of the object or right clicking on its name in the Navigation Tree and selecting '''Show LCS''' from the contextual menu. This will display the red, green and blue local X-, Y- and Z-axes of the objects in dashed lines. To disable the LCS, select '''Hide LCS''' from the contextual menu of that object.
 
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[[Image:lcs_tn_new.png|thumb|left|450px|The local Coordinates System (LCS) of Basic Shapes.]]
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=== Organizing Objects in Color Groups ===
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[[Image:cad_manual-0_new.png|thumb|left|360px480px|CubeCAD's Navigation Tree.]]
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You can move objects from one color to another in CubeCAD. You can also move objects from CubeCAD to other modules or among different modules. To transfer an object from its current color group to another color group, first select it in the Project Workspace and right click on its surface to open the contextual menu. Select '''Move To''' from the contextual menu. This menu item opens up to a number of submenus that include CubeCAD and possibly the names of some other [[EM.Cube]] modules. Each submenu leads to yet other submenus that contain the names of all the object groups that are available for object transfer. For instance, if CubeCAD has three color groups, color_1, color_2, color_3, you will see submenus like''' Move To &rarr; CubeCAD &rarr; Color_1''', '''Color_2''' or '''Color_3'''.Select the desired object group to transfer the selected object to. The transferred object's name is removed from its original color group and is added to the new color group. The color of the transferred object also changes to that of the new color group. In exactly the same way, you can transfer any object from its current group in any module to any other object group in any other module as long as it is listed in the '''Move To''' submenus.
You can also transfer objects from the Navigation Tree. When you import external CAD objects, they are always imported into CubeCAD initially. Then, you have to move them to the right module. In such cases, you can select one of more object names on the Navigation Tree and right click on the highlighted selection to access the '''Move To''' submenus in the contextual menu. If you have highlighted a multiple selection using the '''{{key | Ctrl''' }} or '''{{key | Shift''' }} keys, remember to keep holding those keys down when right clicking; otherwise, you will lose the selection.
<table><tr><td> [[FileImage:moveobject_new.png|500px]] thumb|left|640px|Moving objects from their current color group to other another color group or other to another [[EM.Cube|EM.CUBE]] modulesmodule.]]</td></tr></table>
== Creating New Objects ==
=== Drawing CAD Objects in the Active Color Group ===
At any time, only Only one color group of the Navigation Tree navigation tree is active, where all at any time. All the newly drawn objects are placed and listedbelong to the active color group. CubeCAD displays the active color's name in boldletters. When you start [[EM.Cube]] for the first time and draw a new object in CubeCAD, a default grey color named &quot;Color_1&quot; is immediately created and set as the active color. Every time you create a new color, it is set as the active color. To change the active color, right -click on the name of a color group and select '''Activate''' from the contextual menu. New objects will now be added under the new active color.
To draw an object in [[EM.Cube]], click one of the many '''Object''' buttons in '''Object Toolbar''' and start drawing a new object in the project workspace. Alternatively, you can call on any object creation tool through one of the menu items '''Menu &gt; Object &gtrarr; Solids''', '''Surfaces''' or '''Curves''' submenus. Once an object creation tool is selected, the shape of the cursor changes to a cross, signifying that [[EM.Cube]] is in object creation mode. Left -click anywhere in the Main Window main window to draw an object of the selected type. While the new object is being drawn, a property dialog appears on the lower right corner of the screen. Also, a small '''Help Tip''' window opens up on the upper right corner of the screen that guides you through the drawing process. The property dialog allows you to customize the new object's dimensions and other parameters. The entered values for lengths length parameters are always in the currently selected project units and angles are measured in degrees.
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[[Image:activecolor_new.png|thumb|left|420px480px|Setting the active color.]]
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===The Property Dialog & Object Parameter Types===
Each CubeCAD object has a number of properties that are characteristic to the object type and are listed in its '''Property Dialog'''. When you draw a new object, its property dialog opens up while you are drawing it. After the new object has been created, its properties dialog remains open until you close it. To open the property dialog of an object, double click on the object's surface in the project workspace or first select it and then right click on its surface and select '''Properties...''' from its contextual menu. You can also open an object's property dialog by right -clicking on its name in the navigation tree and selecting '''Properties...''' from the contextual menu. The diagram on the right figure below shows the property dialog of a Box object. <table><tr><td> [[Image:box_tn_new.png|thumb|left|640px|A box object's property dialog and its edit handles.]]</td></tr></table>
All object property dialogs share some common fields:
* Nodal information such as node indices and coordinates (this applies to nodal object types like polyline, polystrip, etc.)
CAD objects are characterized by their Local Coordinate Systems (LCS). Spatial information contains two sets of information: '''LCS Center'''– the X-, Y-, and Z-coordinates of the origin of the local coordinate system, and '''LCS Rotation''' – the right-sense rotation angles of the object about the X, Y, and Z-axes before the object is translated to the specified base center. As you will see later, objects in CubeCAD can be linked to each other. The linkage information part of the property dialog shows whether an object is linked to another &quot;parent&quot; object and if so, in what manner. The type and number of property fields are unique to each differ among the native CubeCAD objectobjects. The box object, for instance, contains Lengthis characterized by '''X-Size''', Width and Height '''Y-Size''', '''Z-Size''' values along with Lock Base two '''Fix Center''' check boxes and two '''Cap Ends ''' check boxes. ===Modifying Objects Using Edit Handles=== Once you finish drawing an new object in the default &quot;Draw &amp; Edit&quot; mode or when you open the property dialog of an object, [[EM.Cube]] enters its &quot;Object Edit Mode&quot;. In this mode, a number of small red balls appear on the object that are called &quot;Edit Handles&quot; and are located at some of the object's snap points The exact number of edit handles varies among the different object types. For example, a box has six edit handles, one at the center of each face. A rectangular strip has four edit handles, one at the midpoint of each edge. A line has two edit handles at its two ends. In the &quot;Object Edit Mode&quot;, you can grab an edit handle and drag it with the mouse to change the size or shape of an object. By grabbing we mean first hovering on the handle (mouse-over) to highlight it and then clicking the left mouse and dragging it around. In dimensional objects, grabbing an edit handle usually changes a certain length or an angle. In nodal objects, grabbing an edit handle changes the position of a node. === General Drawing Rules === By default, when you draw a new object, its property dialog appears at the lower right corner of main Window, and [[EM.Cube]]'s object edit mode is enabled. This means that you can edit the newly drawn object at this time. After the drawing is completed, the mouse cursor changes to its &quot;Normal&quot; arrow shape. Besides the default &quot;Draw &amp; Edit&quot; mode, [[EM.Cube]] provides another drawing mode called &quot;Persistent Draw&quot;. In this persistent mode, after you complete the drawing of an object, the mouse cursor does not return to &quot;Normal&quot; and stays in the drawing mode. You can continue drawing more objects of the same type as many as you like. Switching the drawing mode is done from the User Preferences Dialog, which can be accessed from '''Edit Preferences...''' In the &quot;Drawing Mode&quot; section of the '''Objects''' tab of this dialog, select the radio button labeled '''Persistent Draw'''. In this mode, you will still see the object's property dialog at the lower left corner of Main Window. You can hide this dialog by unchecking the box labeled '''Display Properties'''.
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<td> [[Image:box_tn_newpersistent.png|thumb|left|540px480px|A CAD objectChanging CubeCAD's property drawing mode from the preferences dialog and its edit handles.]]</td>
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===Modifying Objects Using Edit Handles===A number of object types have additional drawing modes, where you can fix their LCS center. These objects are: *Box*Pyramid*Rectangle Strip*Ellipse Strip*Line*Super-Quadratic Curve Of the above list, box, pyramid, rectangle strip, ellipse strip and super-quadratic curve (<i>i.e.</i> all but line) have fixed centers by default. This means that when you draw these objects or later edit them, the coordinates of their LCS centers remains fixed. As a result, as you draw the base of a box or a pyramid in the XY plane, or as you draw a rectangle strip, an ellipse strip or a super-quadratic curve in the XY plane, the dimensions of the object expand or shrink in equal amounts along the &plusmn;X-axis, and so do they along the &plusmn;Y-axis. By contrast, the line object doesn't have a fixed center by default. This means that the length of the line object always expands away from or shrinks towards its start point. If you check the '''Fix Center''' box in the line's property dialog, then its length will changes in equal amounts from both ends.  <table><tr><td> [[Image:lock_base_tn.jpg|thumb|left|480px|Drawing a rectangle strip object without or with a fixed center (locked base).]] </td></tr></table> Except for the line object, you can fix the LCS center of the other object types listed above along the X and Y axes independently. For this purpose, you need to check the boxes labeled '''Fix Center: X''' and '''Fix Center: Y''', respectively, in the object's property dialog. When both boxes are checked, it is called a center-based drawing mode. When box boxes are unchecked, it is called a corner-based drawing mode. In this mode, the object tends to expand away from or shrink towards one of its vertices. When only one of the two "Fix Center" boxes is checked, it is called an edge-based drawing mode. In this mode, the object tends to expand away from or shrink towards one of its edges. When you draw one of the above object types (except for line) for the first time, you are in the center-based drawing mode by default. You can use the keyboard shortcut {{key|B}} successively to toggle among the center-, edge- and corner-based drawing modes after the first point has been established.  <table><tr><td> [[Image:draw_modes_tn.jpg|thumb|left|480px|The center-, edge- and corner-based drawing modes.]] </td></tr></table>
Once you finish drawing an new object in the default == Visual Aids &quot;Draw &amp; Edit&quot; mode or when you open the property dialog of an object, [[EM.Cube|EM.CUBE]] enters its &quot;Object Edit Mode&quot;. In this mode, a number of small red balls appear on the object that are called &quot;Edit Handles&quot; and are located at some of the object's snap points The exact number of edit handles varies among the different object types. For example, a box has six edit handles, one at the center of each face. A rectangular strip has four edit handles, one at the midpoint of each edge. A line has two edit handles at its two ends. In the &quot;Object Edit Mode&quot;, you can grab an edit handle and drag it with the mouse to change the size or shape of an object. By grabbing we mean first hovering on the handle (mouse-over) to highlight it and then clicking the left mouse and dragging it around. In dimensional objects, grabbing an edit handle usually changes a certain length or an angle. In nodal objects, grabbing an edit handle changes the position of a node.Other Convenient Features for Drawing Objects ==
=== Using the Grid & Principal Work Planes ===
[[CubeCAD]] is a full 3D CAD environment that allows you to move your mouse to any arbitrary point in the three-dimensional coordinate space. A work plane is the plane on which the mouse cursor is located and moves freely around. When you start the [[EM.Cube]] application, the mouse always moves on the XY plane, meaning that the XY plane is your default work plane. In addition, [[EM.Cube]] shows the project workspace's grid, and its &quot;Snap-to-Grid&quot; mode is enabled by default even though the project workspace's grid is not displayed by default. As you move the mouse around, it snaps to the invisible grid points. This provides a convenient way to draw objects with precise dimensions and at precise locations. The coordinates of the current location of the mouse are reported in the Status Bar.
[[Image:Info_icon.png|40px30px]] Click here to learn more about [[EM.Cube]]'s '''[[Getting_Started_with_EMGetting Started with EM.CUBECube#The_Grid|Grid]]''' or '''[[Glossary of EM.Cube's Basic File, Edit & View Operations#Grid Properties | Grid Properties]]'''.
Using the View Toolbar, you can easily change the work plane to any of the three principal coordinate planes:
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[[Image:cone_plane_new.png|thumb|left|720px|Drawing a cone at three different principal (XY, YZ and ZX) work planes.]]
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=== Object Snap Points & EM.Cube's Snap Modes===
Every [[EM.Cube]] standard geometric object has a number of '''Snap Points''' that are strategically located on it for a variety of purposes. Snap points are very important in [[EM.Cube]]. Many CAD operations and object transformation tools work based on snap points. Each solid object in general has a number of faces, edges and vertices (or nodes).A surface object normally has one face, a number of edges and vertices. A curve usually has one edge and two or more nodes. In most [[EM.Cube]] objects, the centers of faces, the midpoints of edges and the nodes or vertices constitute the snap points of that object. For example, a Box has six face snap points, twelve edge snap points and eight vertex snap points.
When you start the [[EM.Cube]] application, it is by default in the '''Snap to Object''' mode. This means that when you move the mouse over the surface of an object (without clicking), the object becomes highlighted with a translucent shade of the selection color (yellow by default). If the object is a solid, you can see inside of the object. If you get close to a vertex, the mouse snaps to that vertex. Similarly, if you get close to the middle of an edge, the mouse snaps to the edge's midpoint. Or on a face, the mouse snaps to the center of that face. When the mouse snaps to an object's snap point, a small circle in the complementary selection color (dark blue by default) appears on the snapped point. We refer to this as a &quot;Mouse-Over&quot; state. At this state, the '''Status Bar''' reports the coordinates of the snapped point. If the snapped point is the center of a face, the perimeter of that face is also highlighted in the same color. If the snapped point is the midpoint of an edge, that edge is also highlighted. If you move the mouse slightly away from the snapped point, it unsnaps and starts moving freely on the work plane until it snaps again to another available snap point.
Sometimes, highlighting objects simply by mouse-over may turn out to be rather bothersome especially in dense structures. In this case, you can turn off the &quot;Snap to Object&quot; mode. To do so, double click on the small window at the right end of the Status Bar, which reports the current state of object snap mode. This will cycle through the different objects snap mode. Continue double clicking until you get '''Obj. Snap: OFF'''. Double clicking one more time will lead to '''Obj. Snap: ON'''. You can also enable the '''Snap to Object''' mode using the keyboard shortcut '''O'''. The illustration below depicts several objects and their corresponding snap points.
Accessing all the available snap points of an object can be quite tricky. When the mouse hovers over an object, you can more easily access the hidden snap points (those associated with the hidden faces or edges or corners) by holding down the keyboard's '''{{key | Ctrl }} Key''' and positioning the mouse close to the desired point.
{{Note|Snap to object always has priority over snap to grid. In other words, the mouse jumps from a grid node point immediately to the closest object snap point.}}
{{Note|Mouse-over and highlighting objects works only in one of the four object snap modes.}}
<table><tr><td> [[FileImage:snapedge_tn_new.png|status bar]] thumb|left|640px|Snapping to an object edge and viewing the mouse coordinates in Status Bar.]]</td></tr></table>
=== Drawing New Objects Using Other Objects' Snap Points ===
</table>
=== Setting Up Quick Standard or Non-Principal Work Planes ===
Setting the right work plane is very important for the following reasons:
* Surfaces and curves are always drawn on the active work plane. As for Helix, its turns are parallel to the active work plane while its axis is normal to that plane.
* The LCS of [[Solid Objects|solid objects]] is drawn with local X- and Y-axes in the active work plane and the local Z-axis normal to it. This means that the bottom base of all boxes, cylinders, cones and pyramids are always drawn on the active work plane. Spheres, ellipsoids and tori are always drawn centered on the active work plane.
[[EM.Cube|EM.CUBE]]'s Work Plane tool lets you set up arbitrary work planes anywhere in the Project Workspace. In most casesOftentimes, you may simply need to set up your work plane at an offset distance from parallel to one of the three principal XY, YZ or ZX planes. For example, in layered structures, it is convenient to set up the work plane but at the interface between two layersan offset distance. [[EM.Cube|EM.CUBE]] provides an easier way to set up a work plane that is parallel to XY, YZ or ZX planes. For easy shortcuts for this purpose, you need to target an object snap point. Mouse-Hover the mouse over any object in the Project Workspace project workspace and highlight one of the snap points of that object. Then, type '''{{key|X'''}}, '''{{key|Y'''}}, or '''{{key|Z''' }} on your keyboard. This will establish a new work plane centered at the snapped point and parallel to the YZ, ZX or XY planes, respectively. These are simply [[Keyboard Shortcuts|keyboard shortcuts]] to quickly establish a standard You can also set up an arbitrary work plane. Once non parallel to any of the new work plane appears, you can open the Work Plane Dialog to changes its [[parameters]] including location, orientation and appearanceprincipal coordinate planes.
[[FileImage:standardworkplane_tn_newInfo_icon.png|workplane offset30px]] Click here to learn how to set up an '''[[Glossary of EM.Cube's Basic File, Edit & View Operations#Arbitrary Work Plane|500pxArbitrary Work Plane]]'''.
Setting up Once a quick standard new work plane parallel is established, the movement of your mouse will be bound to YZ that plane using . In other words, the keyboard shortcut cursor will move freely on the surface of the new work plane. The status bar now reports the &quot;User Coordinates&quot; of the cursor position as opposed to its &quot;World Coordinates&quot;. The status bar also shows the word '''User''' in front of these coordinates. You can switch back to the world coordinates at any time by double-clicking on the word '''User''', which changes it to '''World'''. Double-clicking once again toggles the state back to the user coordinates. Any object that you draw on the new work plane will have its local X- and Y-axes on this plane, and its local Z-axis normal to the plane.
=== Setting Up an Arbitrary Work Plane ==={{Note|A new work plane will stay in effect until you switch to one of the three principal work planes.}}
Sometimes you may want to create objects at a certain distance away from one of the three principal work planes. In some other cases, you may want to set up an arbitrary work plane. <table><tr><td> [[EMImage:standardworkplane_tn_new.Cubepng|EM.CUBE]] lets you set thumb|left|640px|Setting up an arbitrary a quick standard work plane different than the three principal coordinate planes. Before learning parallel to do this, let's first consider YZ plane using the different ways you can define an arbitrary plane in [[EMkeyboard shortcut X.Cube|EM.CUBE]]:</td></tr></table>
* Any planar face of a solid or surface object defines a unique plane.* A point and a vector uniquely define a plane.* Any three non-collinear points in space define a unique plane.== Geometric Object Operations & Transformations==
[[EM.Cube|EM.CUBE]]'s Work Plane Tool lets you define any arbitrary work plane using one of the above three methods. Click on the '''Work Plane''' [[File:arbitgrid_tool_tn.png]] button in the '''View Toolbar'''=== Changing Object Visibility, or select ''' Menu [[File:larrow_tn.png]] View [[File:larrow_tn.png]] Work Plane [[File:larrow_tn.png]] Arbitrary Plane''', or use the keyboard shortcut '''W''' to enable [[EM.Cube|EM.CUBE]]'s &quot;Work Plane ModeColor &quot;. The Work Plane Dialog opens up at the lower right corner of the screen. Below are three different ways that you can define a new arbitrary work plane:Texture ===
* Mouse-over any object in the Project Workspace You can hide and click on a face snap pointshow individual objects, icolor groups and even the entire parts.e. the center This can be very helpful when you work with structures that contain a sizable number of parts containing large and small objects in close proximity of a highlighted planar faceone another. A new work plane appear overlaid Hiding individual objects or color groups allows you to focus on the selected facepoints of interest within your structure.* Or while you are in one of To hide or show individual objects or color groups or the three principal Xy, YZ or ZX work planesentire parts, right-click any blank point and drag the mouse. A semi-translucent plane perpendicular to the current work plane is drawn and displayed in the Project Workspace. The normal plane follows on the movement name of the mouse as you drag it. Once you reach the desired orientationobject, double click color or type the keyboard&quot;Parts&quot; item in the navigation tree and select 's' 'Hide'Enter Key''or ' to finalize the new work plane.* Or click on any blank point and select two more points anywhere in the workspace (including other objects' snap points). A new work plane is established that passes through 'Show''' from the three selected pointscontextual menu.
In all the three cases aboveYou can also freeze individual objects or color groups. When an object is frozen, [[EM.Cube]] shows only a translucent plane appears showing the location and orientation wireframe of the new work plane. The transverse axes (local X and Y axes) of the new work plane are displayed that object in red and green colors, respectivelyits own color. A new &quot;User Coordinate System (UCS)&quot; is established on the new work plane. In the Work Plane DialogYou cannot mouse-over, you can see the world coordinates of the center of the UCS and its rotation angles with respect to highlight or select a frozen object in the project's world coordinate system (WCS)workspace. From this dialog you can change both the center coordinates and the rotation angles. This will change the location and orientation of the new arbitrary work plane. Once you are content with the location and orientation of the new work planeTo freeze an individual object or a color group, you can also change right-click on its visible size. Note that name in the visible size of the work plane is purely for visualization purposes; otherwise, the work plane has infinite extents. You can change both navigation tree and select '''LengthFreeze''' from the contextual menu. To unfreeze a frozen object or color group, right-click on its name in the navigation tree and remove the check mark already placed before the '''WidthFreeze''' of item in the work plane separatelycontextual menu. You can also change freeze individual geometric objects using their contextual menu in the '''Color''' and '''Transparency''' level of the work planeproject workspace by right-clicking on their surface.  {{Note|You cannot highlight &quot;frozen&quot; objects by mouse-over.}}
<table>
<tr>
<td>
[[Image:workplane_newobjectfreeze_tn_new.png|thumb|left|480px540px|EM.Cube's work plane dialogFreezing objects in the project workspace.]]
</td>
</tr>
</table>
Once You can edit an existing color from a new work plane is established, the mouse will be bound to that planegroup's property dialog. In other words, the cursor will move freely Right-click on the surface name of a color group on the new work plane. The navigation tree and select '''Status BarProperties...''' now reports from the &quot;User Coordinates&quot; of the cursor position as opposed to its &quot;World Coordinates&quot;contextual menu. The status bar also shows This opens up the word '''User''' in front property dialog of these coordinatesthe selected color. You can switch back to change the world coordinates at any time default color by double clicking the word '''User''', which changes it to '''World'''. Double clicking once again toggles the state back to the user coordinates. Any object that you draw on the new work plane will have its local X and Y-axes on this plane, and its local Z-axis normal to the plane. While a non-principal work plane is active, you can always summon its dialog and change its properties. To do so, click on the '''Work Plane''' button in the '''View Toolbar''', or select '''Menu [[File:larrow_tn.png]] View [[File:larrow_tn.png]] Work Plane [[File:larrow_tn.png]] Arbitrary Plane''', or use the keyboard shortcut '''W'''. {{Notekey|A new work plane will stay in effect until Color}} button to switch to one of open up the three principal work planesstandard color palette.}}
<table>
<tr>
<td>
[[Image:arbitworkplane_tn_newsetcolor_new.png|thumb|left|550px720px|Setting up an arbitrary work plane in Changing the project workspacecolor of a color group.]]
</td>
</tr>
</table>
== Object Operations By default, the color groups do not have a texture. You can replace a solid color with a texture that is generated from a bitmap image. First, you have to check the box labeled '''Texture'''. This enables the texture section of the dialog. Click the {{key|Texture}} button to open Windows' Open Dialog. The file type is set to & Transformations== quot;Bitmap Files (*.bmp)&quot;. Use the {{key|Browse}} button to find the desired bitmap file and open it. Next, you have to define the texture mapping scale. On the geometric objects, the texture will show up as tiles of the imported bitmap. In the "Texture Geometry" section of the dialog, two boxes show the '''Width''' and '''Height''' of the bitmap in pixels. You need to map these onto the desired tile width and height in project units. These settings determine how many texture tiles appear on each object given its dimensions. If large values are set for the tile width and height, partial bitmap will show up on the objects. You also have the option to apply the texture to the '''Side Only''' by checking the related box.
=== Changing Object Visibility, Color and Texture ===<table><tr>You can hide and show individual objects, color groups and even the entire parts. This can be very helpful when you work with structures that contain a significant number of parts containing large and small objects in close proximity to one another. Hiding individual objects or color groups allows you to focus on the points of interest within your structure. To hide or show individual objects or color groups or the entire parts, right click on the name of the object, color or the &quot;Parts&quot; item in the Navigation Tree and select '''Hide''' or '''Show''' from the contextual menu. You can also freeze individual objects or color groups. When an object is frozen, [[EM.Cube|EM.CUBE]] shows only a wire-frame of that object in its own color. You cannot mouse-over, highlight or select a frozen object in the Project Workspace. To freeze an individual object or a color group, right click on its name in the Navigation Tree and select '''Freeze''' from the contextual menu. To unfreeze a frozen object or color group, right click on its name in the Navigation Tree and remove the check mark already places before the '''Freeze''' item in the contextual menu. {{Note|You cannot highlight &quot;frozen&quot; objects by mouse-over.}}<td> [[FileImage:objectfreeze_tn_newtexture_tn1.png|selectingthumb|500pxleft|450px|A bitmap image.]]</td>Freezing objects in the Project Workspace.</tr></table>You can change the default color by clicking the button labeled '''Color''' to open up the standard color palette. You can edit an existing color through its Property Dialog. Right click on the name of a color group on the Navigation Tree and select '''Properties...''' This opens up the Property Dialog of the selected color. You can change the name, color or texture of the group just as explained later.<table><tr>By default, the color groups do not have a texture. You can replace a solid color with a texture that is generated from a bitmap. First, you have to check the box labeled '''Texture'''. This enables the texture section of the dialog. Click the '''Texture''' button to invoke [[Windows]]' Open Dialog. The file type is set to &quot;Bitmap Files (*.bmp)&quot;. Use the Browse button to find the desired bitmap file and open it. Next, you have to define the texture mapping scale. On the objects, the texture will show up as tiles of the imported bitmap. In the Texture Geometry section of the dialog, two boxes show the '''Width''' and '''Height''' of the bitmap in pixels. You need to map these onto the desired tile width and height in project units. These settings determine how many texture tiles appear on each object given its dimensions. If large values are set for the tile width and height, partial bitmap will show up on the objects. You also have the option to apply the texture to the '''Side Only''' by checking the related box.<td> [[FileImage:setcolor_newtexture_tn2.png|500px]] Changing thumb|left|550px|Setting the color texture of a color group. [[File:texture_tn.png|500px]]</td>Setting the texture of a color group.</tr></table>
=== Selecting, Cutting, Copying, Pasting &amp; Deleting Objects ===
In order to modify or apply CAD operations to objects, they must first be selected. The navigation tree provides a convenient interface that allows you to select one or more objects. The simplest way to select an object is to click on its surface in the project workspace. When an object is selected, its color changes to the &quot;Selection Color&quot; (yellow by default). When you select an object in the project workspace, its name on the navigation tree is highlighted in the selection color. Alternatively, you can select an object by clicking on its name in the navigation tree. In that case, the selected object's name is highlighted in the navigation tree, and the object itself is highlighted in the selection color in the project workspace. To deselect a selected object, simply click on any blank point in the project workspace.
You can select more than one object at a time. There are several ways to do a multiple selection. The simplest way is to select the first object in the project workspace. Then, while holding the keyboard's {{key|Ctrl}} key down, click on the second and subsequent objects that you want to add to the selection. You can follow the same procedure in the navigation tree. While holding the keyboard's {{key|Ctrl}} key down, click on the names of all the objects you want to select in the navigation tree. In a &quot;Range Selection&quot;, you can select a sequential set of objects belonging to the same color group. First, you click on the name of the first object in the navigation tree. Then, while holding the keyboard's {{key|Shift}} key down, you click on the name of the last object to be selected. All the objects whose name names are listed between those two objects are also selected and highlighted.
Cut, copy, paste and delete are some of the most common edit operations. As in many other Windows applications, you can cut an object (from the workspace) and hold it in the Windows' clipboard until you paste it back to the workspace. You can also copy an object and paste it back to the workspace. Deleting an object removes it forever from the project workspace, although you can undo your delete operation.
<tr>
<td>
[[Image:selection2_tn_new.png|thumb|left|450px640px|Selection of one or more objects (selection color is yellow).]]
</td>
</tr>
The simplest way to cut, copy, paste o delete an object or a selection of objects is using the keyboard shortcut {{key|Ctrl+X}}, {{key|Ctrl+C}}, and {{key|Ctrl+V}}, respectively, or use the keyboard's {{key|Delete}} key. You can also use the {{key|Cut}}, {{key|Copy}}, {{key|Paste}} and {{key|Delete}} buttons of '''System Toolbar''' or similar items of the '''Edit Menu'''. The right-click contextual menu of objects in the project workspace or on the navigation tree yet provide additional ways for cutting, copying, pasting and deleting objects.
When you paste an object or a selection of objects to the project workspace, [[CubeCAD]] allows you to place the pasted object(s) in any arbitrary location right away. First, a wire-frame of the pasted object(s) appears in the workspace, which you can drag around with the mouse. Wherever in the workspace you click the mouse, the pasted object(s) will be dropped. A dialog titled &quot;Place&quot; appears on the lower right corner of the screen that shows the current coordinates of the mouse point (as you drag it) in three X-, Y- and Z-coordinate boxes labeled '''Destination''' as well as three X-, Y- and Z-coordinate boxes labeled '''Vector'''. The vector coordinates show the Cartesian components of the displacement vector pointing from the original position of the cut or copied object(s) to the current mouse position. As you drag the mouse around, all these values get updated continuously. You can fine-tune the final location of your pasted object using either of the two coordinate sets. ===Operational Modes of CubeCAD Tools=== Each of CubeCAD tools performs a certain operation or transformation on one or more selected CAD objects. [[EM.Cube]] provides a number of different ways to use these tools. First, you have to activate a CAD tool. Each tool has a button with a particular icon on '''Tools Toolbar''', which you can click to activate. If you hover your mouse on one of these buttons before clicking, a small tooltip shows up displaying the name of that tool. You can also enable a tool from '''Tools Menu''' at the top of the screen. Many tools have a keyboard shortcut, which you simply type on your keyboard to enable that tool. You can also access some tools from the contextual menu of individual objects either by right-clicking on the surface of an object in the project workspace or by right-clicking on the object's name in the navigation tree. When you access a CAD tool from Tools Toolbar or Tools Menu, one or more '''Help Tips''' appear on the upper right corner of the screen, which guide you along the different steps of usage of the enabled tool. The first step in using each CAD tool is to select one or more objects. When you activate a tool from Tools Toolbar or Tools Menu, a help tip prompts you to select an object by clicking on it. If the enabled tool allows the selection of more than one object (e.g. Group Tool), you can select the objects one by one and then press the '''Enter Key''' to finish the object selection. At this point, another help tip instructs you to take the next action. For most tools, alternatively, you can first select the object(s) and then activate the tool in one of the ways mentioned earlier. This is often more convenient and spares a few mouse clicks. ===Working with Generic Objects=== [[EM.Cube]] offers a large selection of parameterized native objects. Many of CubeCAD tools, such as translate, rotate or mirror, transform native objects to other objects of the same kind or result in the creation of other types of native objects like polylines and polystrips. Some other CAD tools result in the creation of a generic solid object, a generic surface object or a generic curve object. [[EM.Cube]]'s generic objects have a limited number of parameters. They have three '''LCS Coordinates''' and three '''Rotation Angles''', which determine their location and orientation in the project workspace. You can change these parameters by accessing the property dialog of a generic object. They also have '''Dimension''' parameters, which represent the size of the their bounding box along the three principal directions, but they are not editable. Most CAD import operations bring in external CAD files to your project workspace as generic objects. ===Working with Transform Objects=== Many of CubeCAD operations and transformations result in the creation of either native objects like polylines and polystrips or in generic curve, surface or solid objects. Each of the following tools, however, creates a special "Transform Object": # [[Glossary_of_EM.Cube%27s_CAD_Tools#Group_Tool | Group Tool]]# [[Glossary_of_EM.Cube%27s_CAD_Tools#Array_Tool | Array Tool]]# [[Glossary_of_EM.Cube%27s_CAD_Tools#Subtract_Tool | Subtract Tool]]# [[Glossary_of_EM.Cube%27s_CAD_Tools#Union_Tool | Union Tool]]# [[Glossary_of_EM.Cube%27s_CAD_Tools#Intersect_Tool | Intersect Tool]]# [[Glossary_of_EM.Cube%27s_CAD_Tools#Extrude_Tool | Extrude Tool]]# [[Glossary_of_EM.Cube%27s_CAD_Tools#Loft_Tool | Loft Tool]]# [[Glossary_of_EM.Cube%27s_CAD_Tools#Revolve_Tool | Revolve Tool]]# [[Glossary_of_EM.Cube%27s_CAD_Tools#Polymesh_Tool | Polymesh Tool]]# [[Glossary_of_EM.Cube%27s_CAD_Tools#Random_Group_Tool | Random Group Tool]]# [[Glossary_of_EM.Cube%27s_CAD_Tools#Roughen_Tool | Roughen Tool]] Each transform object has a special property dialog. The Group tool and the three Boolean operation tools, Subtract, Union and Intersect, have similar property dialogs and allow you to access their constituent objects. The property dialog of composite or Boolean objects has a '''Member List''' containing the names of all constituent objects. You can highlight and select any member from this list and click the '''Edit''' button of the dialog to open up its property dialog, where you can edit its properties.  The property dialog of Extrusion, Loft, Revolution, Polymesh and Rough objects has an '''Edit Primitive''' button, which lets you access the property dialog of the original object used for the generation of the selected transform object. After you finish editing the primitive object, you will return to the property dialog of the transform object. Array and Random Group objects are arrangements of clones of an original key object. In these cases, the '''Edit Primitive''' button opens up the property dialog of the key element.
===Glossary of EM.Cube CAD Tools===
[[EM.Cube]] provides a large number of CAD tools that translate, rotate, scale and perform more complex geometric transformations on one or a selection of several objects.
[[Image:Info_icon.png|40px30px]] Click here to To learn more about the various types of geometric object transformations and edit operations, see the '''[[Glossary_of_EMGlossary of EM.Cube%27s_CAD_Tools| 's CAD Tools & Geometric Transformations]]'''.
==Importing & Exporting External CAD Models==
=== Importing Objects from External Files ===
Building complex simulations geometries often requires one to the import CAD objects from of external filesCAD models. Currently, [[EM.Cube]] can read in import the following CAD file formats:
* # STEP File (*.STEP or *.STP)* # IGES File (*.IGES or *.IGS)* # Stereolithography File (*.STL)* # Raw Triangles (*.RAW)* # Shape File (*.SHP)* # CUBIT Facet File (*.FACET)* # ASCII DXF File (*.DXF)* # Digital Elevation Map (DEM) File (*.DEM)* # Python File (*.PY)
To import an external file of one of the above formats, select the menu item '''Menu > File > &rarr; Import...''' Once the standard [[Windows]] "Open Dialog " pops up, select the desired file extension from the dropdown drop-down list labeled &quot;Files of typeType:&quot;. Then, select the desired file and click the '''{{key|Open''' }} button of the dialog. This opens another dialog that shows the progress of loading the imported file. You can abort the import process by clicking the '''{{key|Abort Translation''' }} button. You can also view a report of the process. All imported objects are listed under "Color_1". From this group you can move them to other groups. In some cases, the imported object might already be organized in different colors or groups. In all file formats except for STLand Facet, [[Solid Objects|solid objects]] are imported as [[EM.Cube]]'s generic solids and [[Surface Objects|surface objects]] are imported as [[EM.Cube]]'s generic surfaces. From STL and Facet files, objects are imported as [[EM.Cube]]'s native polymesh objects.
{{Note|You can import external CAD files only into [[CubeCAD]]. From here , from which you can then move the imported objects to [[EM.Cube]]'s other modules.}}
<table>
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<td>
[[Image:import3_tn_new.png|thumb|left|500px720px|The imported STEP model of a helicopter.]]
</td>
</tr>
=== Exporting Project Structure ===
You can save the structure that you build in [[EM.Cube]] to an external CAD file for later use or transfer to other applications. Currently, [[EM.Cube]] can write out export the physical structure to the following file formats:
* # STEP File (*.STEP or *.STP)* # IGES File (*.IGES or *.IGS)* # Stereolithography File (*.STL) - ASCII* # Stereolithography File (*.STL) - Binary* # CUBIT Facet File (*.FACET)* # DXF File (*.DXF)* # Python File (*.PY)
To export the project structure to an external file of one of the above formats, select the menu item '''Menu > File > &rarr; Export...''' Once the standard [[Windows]] "Save As Dialog " pops up, select the desired file extension from the dropdown drop-down list labeled &quot;Save as type:&quot;. Then, type in a name for the file and click the '''Save''' button of the dialog. This opens another dialog that shows the progress of writing the exported file. You can abort the export process at any time by clicking the '''Abort Process''' button.
Note that in the case of DXF export, all the surface CAD objects lying in the XY Plane or in any horizontal plane and only rectangular objects lying in the YZ or ZX planes or in any vertical plane parallel to these planes are exported. Curve and solid CAD objects are ignored during the export process.
===Working with STL ModelsCubeCAD's Triangular Surface Mesh ===
Stereolithography files contain a tessellated (triangulated) representation Mesh generation is an important part of a structurecomputational engineering. [[EM.Cube|EM.CUBE]] treats STL files in A mesh is used to discretize a special way. You can export the project structure continuous geometry into a STL file in the form set of a polymesh object. This is similar to writing the structure much simpler elementary cells or "mesh data into a mesh data file of &quot;.msh&quot; extension. The project structure is tessellated using [[CubeCAD|CUBECAD]]'s triangular surface mesher of the '''Structured Type'''elements". As you will see in [[EM.Cube|EM.CUBE]] gives you two options for STL export: '''Binary STL''' and '''ASCII STL'''. The latter file is bigger in size. You can import STL files of both binary and STL types into s other modules, [[EM.Cube|EM.CUBE]]. STL models are imported as native polymesh objects. As a result, you can edit the imported objects and modify their various [[parameters]] arbitrarily. This is in contrast to importing files provides several mesh generators of other formats, which create solid and [[Surface Objects|surface objects]] of the generic typedifferent types. Once you import a STL file, you can change the mesh type The accuracy of the imported object to the '''Regular Type'''. You can also decrease the '''Edge Length''' to obtain a higher resolution. Just like other polymesh objects, you can insert nodes numerical simulation often depends directly on the faces quality and edges or delete nodes from resolution of the imported objectmesh.
=== CubeCAD provides a triangular surface mesh generator that discretizes surface objects and the surface of solid objects based on a specified edge length. The mesher algorithm generates a regularized mesh and attempts to create triangular cells of almost equal area. CubeCAD's Surface Mesh ===mesh generator polygonizes curve objects based on the same edge length.
=== Generating and Controlling the Mesh generation is an important part of computational engineering. A mesh is used to discretize a continuous geometry into a set of much simpler elementary cells or mesh &quot;elements&quot;. [[Solid Objects|Solid objects]] can be discretized into tetrahedral elements. Surfaces can be meshed using triangular cells. Curves can be discretized into polylines. As you will see in [[EM.Cube|EM.CUBE]]'s other modules, [[EM.Cube|EM.CUBE]] provides a large number of diverse mesh generators. The accuracy of a numerical simulation often depends directly on the quality of the mesh. It is also important to be control the resolution of a mesh, namely, the size of mesh cells. Higher mesh resolutions normally lead to better accuracy of the numerical results.===
Tetrahedral and surface triangular meshes are one of the most widely used mesh types in many different engineering disciplines. [[CubeCAD|CUBECAD]] provides two types of mesh generation algorithms for [[Discretizing Objects|discretizing objects]]. The first one generates You can generate a wire-frame surface triangular mesh of [[Surface Objects|surface objects]] and a polyline mesh of [[Curve Objects|curve objects]]. The [[Solid Objects|solid objects]] are treated as closed surfaces and are discretized using a similar wire-frame surface mesh. the physical structure in other words, objects of all types are meshed in some sort. The wire-frame mesh generator has two variations. The first algorithm generates a regularized mesh and attempts to create triangular cells of almost equal size. The second algorithm tries to create a structured mesh with cells of similar patterns. [[CubeCAD|CUBECAD]]'s other mesh generator generates a tetrahedral mesh for [[Solid Objects|solid objects]]. Tetrahedral meshes are usually enormous in size. Note that surface and [[Curve Objects|curve objects]] cannot be discretized using this type one of mesh generator.the following three ways:
# By clicking the '''Show Mesh''' [[File:cadmesh1_tn_newmesh_tool_tn.png|260px]] [[File:cadmesh2_tn_newbutton of the Simulate Toolbar.png# By selecting the menu item '''Simulate &rarr; Discretization &rarr; Show Mesh'''.# Using the keyboard shortcut {{key|260px]]Ctrl+M}}.
A sphere When the mesh is displayed in the project workspace, [[EM.Cube]]'s mesh view mode is enabled. In this mode, all the objects are discretized using CubeCAD's mesh generation algorithm and the meshes of all objects are displayed. In mesh view, you cannot mouse-over, select or edit any objects. The mesh view is for viewing purpose only. You can perform most of view operations such as zooming in and out using the mouse scroll wheel, rotating the view using the right mouse button {{key|RMB}} and panning the view using {{key|Shift+RMB}}. When [[EM.Cube]] is in mesh view mode, the '''Show Mesh''' [[File:mesh_tool_tn.png]] button of Simulate Toolbar remains depressed. To hide the mesh, exit the mesh view mode and return to the normal view mode, simply click the '''Show Mesh''' [[File:mesh_tool_tn.png]] button one more time to toggle its surface triangular state, or press the keyboard's {{key|Esc}} (Escape) key, or select the menu item '''Simulate &rarr; Discretization &rarr; Show Mesh''' and tetrahedral meshesremove the check mark in front of it.
===Generating and Controlling the Mesh===<table><tr><td> [[Image:cadmeshsettings_new.png|thumb|left|480px|CubeCAD's mesh settings dialog.]]</td></tr></table>
You can change the mesh type and the mesh resolution from CubeCAD's Mesh Settings dialog. Click the '''Mesh Settings''' [[File:cadmeshsettings_newmesh_settings_tn.png|thumb|250px|CUBCAD]] button of the Simulate Toolbar or select the menu item 's ''Simulate &rarr; Discretization &rarr; Mesh Settings dialog...''' In the drop-down list labeled '''Mesh Type''' you can select one of the two options: '''Regular Surface''' or '''Tessellated Surface'''. The latter option shows the simplest tessellation of the physical structure. The mesh resolution is controlled by '''Edge Length''', which is expressed in project units. The default value of edge length is 10 units. This means that the default mesh features cells with a size of about 10 units. When you change the mesh type or resolution, you can see the effect using the {{key|Apply}} button if [[EM.Cube]]is already in mesh view mode. After [[EM.Cube]] generates a mesh, it saves it and uses it the next time you want to see the mesh. The mesh stays the same until you change its parameters. Sometimes, you may want to regenerate the mesh with the same current parameters. To do so, select the menu item '''Simulate &rarr; Discretization &rarr; Regenerate Mesh'''.
You can generate a mesh of the structure in [[CubeCAD|CUBECAD]] in one of the following three ways:<table><tr><td> # By clicking the '''Show Mesh'''[[FileImage:mesh_tool_tncadmesh1_tn_new.png]] button |thumb|left|480px|The geometry of '''Compute Toolbar'''two spheres.# By selecting '''Menu [[File:larrow_tn.png]] Compute [[File:larrow_tn.png]] Discretization [[File:larrow_tn.png]] Show Mesh'''.# Using the keyboard shortcut '''Ctrl+M'''.</td></tr><tr><td> When the mesh is displayed in the Project Workspace, [[EMImage:cadmesh2_tn_new.Cubepng|thumb|left|480px|EM.CUBE]]'s mesh view mode is enabled. In this mode, all the objects are discretized using the selected mesh generation algorithm and the meshes of all objects are displayed. In mesh view, you cannot mouse-over, select or edit any objects. The triangular surface mesh view is for viewing purpose only. You can perform most of view operations such as zooming in and out using the mouse scroll wheel, rotating the view using the right mouse button '''RMB''' and panning the view using '''Shift+RMB'''. When [[EM.Cube|EMtwo spheres generated by CubeCAD.CUBE]] is in mesh view mode, the '''Show Mesh'''[[File:mesh_tool_tn.png]] button of '''Compute Toolbar''' remains depressed. To hide the mesh, exit the mesh view mode and return to the normal view mode, simply click the '''Show Mesh'''[[File:mesh_tool_tn.png]] button one more time to toggle its state, or press the keyboard's '''Esc Key''' (Escape), or select '''Menu [[File:larrow_tn.png]] Compute [[File:larrow_tn.png]] Discretization [[File:larrow_tn.png]] Show Mesh''' and remove the check mark in front of it.</td></tr><tr><td> You can change the mesh type and the mesh resolution from the CAD Mesh Settings Dialog. Click the '''Mesh Settings'''[[FileImage:mesh_settings_tncadmesh3_tn_new.png]] button of '''Compute Toolbar''' or select '''Menu [[File:larrow_tn.png]] Compute [[File:larrow_tn.png]] Discretization [[File:larrow_tn.png]] Mesh Settings...'''In the dropdown list labeled '''Mesh Type''' you can select one of the three options: '''Regular Surface''', '''Structured Surface''' or '''Tetrahedral'''. The mesh resolution is controlled by '''Edge Length''' which is expressed in project units. The default value of edge length is 10 units. This means that the default mesh features cells with a size of about 10 units. When you change the mesh type or resolution, you can see the effect using the '''Apply''' button if [[EM.Cube|EM.CUBE]] is already in mesh view mode. After [[EM.Cubethumb|left|480px|EM.CUBE]] generates a mesh, it saves its and uses it the next time you want to see the mesh. The mesh stays tessellated version of the same until you change its [[parameters]]two spheres. Sometimes, you may want to regenerate the mesh with the same current [[parameters]]. To do so, select '''Menu [[File:larrow_tn.png]] Compute [[File:larrow_tn.png]] Discretization [[File:larrow_tn.png]] Regenerate Mesh'''.</td></tr></table>
===Saving Mesh Data to a FileWorking with STL & FACET Models===
CubeCAD generates Stereolithography (STL) files contain a tessellated (triangulated mesh ) representation of a geometrical structure. CUBIT FACET files are used to store surface mesh data. [[EM.Cube]] treats STL and solid objects and FACET files in a special way. You can export the physical structure of your project workspace into a linearized STL or polygonal mesh FACET file in the form of curve polymesh objects. The Your physical structure is tessellated for export using CubeCAD's triangular surface mesh of surface generator. Therefore, you can use CubeCAD's mesher to see and solid objects are equivalent examine how your physical structure is going to be exported and will look like before you export it. [[EM.Cube]]gives you two options for STL export: 's native polymesh objects while the polygonal mesh of curve objects are equivalent to polyline objects. The mesh data can be saved into an ASCII data file with a ''Binary STL'.msh'' and '''ASCII STL''' file extension. The top part of this latter file contains coordinates of all the nodes involved is bigger in the meshsize. Then comes the definition You can import STL files of both binary and STL types into [[EM.Cube]]. Both STL and FACET models are imported as native polymesh objects. As a result, you can edit the elements of facesimported objects and modify their various parameters as you like. Each line defines This is different than the number import of nodes in each element files of other formats, which always create generic solid and surface objects. Just like other polymesh objects, you can insert nodes on the index faces and edges of the imported object or delete some of its nodes . Note that some objects might be imported to CubeCAD in the order presented in the previous node definition section. Thusa freeze state, triangular elements (faces) have three node indices while the linear elements (bars)have two node indicesand you need to unfreeze them before being able to edit their properties.
Polymesh and polyline objects {{Note|FACET files are already discretized and are not meshed again when [[EM.Cube]] generates a mesh of the structure always expressed in the Project Workspacemeters. As suchTherefore, polymesh and polyline objects preserve their nodes as they are saved into before importing a mesh FACET file, you should change the project units to meters.}}
[[File:meshfile1.png]]<br />
The mesh file representing a polymesh surface object.<hr>
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Kazem Sabet
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