Surfaces

Once you have one or more surfaces selected, the following features are found in the Scene Graph under Edit > Surfaces.

• Tessellate Surfaces - VRED uses ray tracing to display NURBS data, without any preparation. In OpenGL mode, VRED tessellates objects to generate a polygonal representation. This involves changing the complexity or number of polygons of an object, at any time. NURBS coexist with polygons on nodes within the Scene Graph. You can re-tessellate without having to reload the files. A polygonal representation will never be as precise as source NURBS data, so more polygons will have to be generated when a higher precision is required.

  The Tessellate Surfaces dialog box contains these settings.

  • Tessellation Quality - Uses the selected preset to determine the approximate tessellation quality. The other option values, such as Chord Deviation, Normal Tolerance, etc. automatically adjust, based on the selected quality.

  • Chord Deviation - Sets the maximum deviation between the NURBS surface and tessellated surface. A low value results in a more accurate polygon model, but increases the number of triangles.

  • Normal Tolerance - Determines the allowed normal deviation between the normals on the endings of a tessellated edge.

  • Max Chord Length - Sets the maximum edge length of the generated polygons. Long polygon edges will not be smoothly shaded within the Render Window. This setting is helpful to avoid this.

  • Enable Stitching - Avoids the ragged edges of a tessellated representation within the Stitching Tolerance. When a surface is tessellated, this process re-builds existing topology and aligns the edges of selected shells to each other. Stitching is required to smooth the edges.

  • Stitching Tolerance - Sets the tolerance where two adjacent edges are considered to be touching and should be stitched together.

  • Preserve UVs - Preserves UVs when enabled. If the geometry is re-tessellated, its UV coordinates can be preserved by checking Preserve UVs in the Retessellation dialog. The UV layout will be transferred from the old to the new tessellated surfaces after tessellation is finished.

    Note:

    When there are UV cuts within a surface, these cuts might not be properly reconstructed after re-tessellation. The algorithm will create a cut in the area of the original cut, but depending on how the triangulation has changed, it can look different. For example, the cut can appear as a jagged line, instead of a straight one.

    Note:

    Edge constraints (see Constraint U / Constraint V) are not kept on retessellation.

• Create Shell From Selection - Combines the selected NURBS components into one contiguous NURBS shell.

• Convert to Mesh - Deletes NURBS information stored with the tessellated object. This reduces memory requirements for the scene, but re-tessellation of that object will no longer be possible.

Geometry

The following features are found in the Scene Graph under Edit > Geometry.

• Merge Geometry - Merges polygonal objects with the same material into one contiguous object. Can also be used on group nodes. Will also work when NURBS data exists with the polygonal representation. If nothing is selected, this applies to all items in the Scene Graph. (Ctrl+Shift+M)

• Split Geometry - Splits the selected object into meshes. In the dialogue box that opens, enter the maximum number of triangles each resulting mesh can have. For example, if there is an object with 1000 polygons and it should be divided into fragments with a maximum number of 100 polygons each, the splitting will yield 10 objects. This cannot be undone.

  Click here to view the Quick Tip - Splitting Geometry video.

• Split Geometry into Primitives - Converts the object into a group node with the same name. The group node contains single triangles for each polygon of the source object. (Ctrl+T)

• Unsplit Geometries with One Triangle - Merges triangles into one object. To combine a number of polygons this way, they should be grouped and this feature used on the group node. Material from the first node below the parent group is applied to the merged object. (Ctrl+Shift+T)

• Subdivide Geometry - Subdivides an existing polygon mesh into smaller triangles. This feature is helpful when NURBS data for re-tessellation is not available, but a refined mesh is required. For example, ambient occlusion calculation requires a fine mesh resolution to avoid ragged edges on shadows.

  In the Subdivide Geometry dialog, select a Subdivision Mode.

  • Standard - Subdivides each polygon until the edge lengths fall below the value entered in the Max Edge Length box.
  • Phong Interpolation - Subdivides each polygon into a specific number of triangles, depending on the value selected in the Iterations box.

Iterations	Triangles/Polygons
1	4
2	16
3	64
4	256

Animation

The following features are found in the Scene Graph under Edit > Animation.

• Load Animation to Nodes - Applies a saved transformation animation to the selected nodes.

• Load Animation to Materials - Applies a saved material animation to the selected nodes.

• Create Turntable Animation - Creates a turntable to rotate the selected object around the perpendicular axis. Adjust settings in the dialog, including:

  • Interpolation - Determines object velocity during animation playback. Linear results in a constant rotation of the object, while Ease In or Ease Out reduces velocity during the beginning or end of the animation.
  • Rotation Pivot(s) - Click Set To Center to set the rotation pivot to the center of the selected object's bounding box.

• Copy Animations - Copies the animation from a selected animated object.

• Paste Animations - Pastes an animation to the selected node.

• Paste Clone Animations - Pastes an animation to the selected node as a reference. This means any change to the animation affects the cloned instance. The reverse is true, as well.

Copy and Paste

Nodes in the Scene Graph can be copied and pasted within the Scene Graph. You can also copy and paste nodes from one instance of VRED to another. With two or more sessions of VRED open, copy nodes from one Scene Graph, select a node in another Scene Graph and paste. The Paste dialog opens with options.

Paste and Clone

Aside from standard delete, copy, and paste functions, VRED includes these clipboard options in the Scene Graph Edit menu. When components are dragged and dropped or pasted in the Scene Graph, shells are created.

• Paste > Paste Clone - Pastes nodes currently stored in the clipboard as a group node of clones in the Scene Graph. The clones are also known as referenced objects. Referenced objects are underlined. (Ctrl+Shift+V)

• Paste > Paste with Transformation - Pastes nodes currently stored in the clipboard to the same location as the originally copied nodes.

• Paste > Paste Clone with Transformation - Pastes nodes currently stored in the clipboard as a group node of clones in the Scene Graph, and in the same location as the originally copied nodes. The clones are also known as referenced objects. Referenced objects are underlined.

• Clone - Combines the Edit menu commands, Copy and Paste Clone, into a single action. The use of one of the mirror commands creates a referenced and mirrored instance of the source object or structure. Referenced nodes are underlined within the Scene Graph. Cloned groups are transformable by default.

  Note:

  Edit > Preferences > Scene Graph > Transformable Clone Root is activated by default.

  • Clone - Creates a cloned instance of the source selection at the same position in 3D. When the Transformable Clone Root is activated, the selected node and its duplicate are synchronized. All children of both nodes are clones of each other. Adding, removing, and reordering children does the same on the children of the synchronized node. The two synchronized nodes can be independently transformed, animated, and named. Only Groups (Transform3Ds) can be synchronized. That means, cloning with the option enabled is only possible on Transform3D nodes. (Ctrl+Shift+D)
  • Clone Mirror X, Y, or Z - Creates a cloned instance of the source selection mirrored on the related axis. When the Transformable Clone Root is activated, the subtree of the selected node is cloned, and the roots of both subtrees (source and result) are synchronized with each other, as with Clone. The cloned subtree is added as a child to a Mirror Transform node.

• Duplicate - Acts the same as Clone, except the new objects are independent, rather than referenced. Additional flush options for axis mirroring, flush the transformations from the sub-tree into the object nodes. (Ctrl+D)

  • Duplicate - Creates an independent instance of the source selection at the same position in 3D. All clone connections are preserved within the duplicate. (Ctrl+D)
  • Duplicate and Keep Clones - Creates an independent instance of the source selection at the same position in 3D. All clone connections are preserved to other parts of the Scene Graph.
  • Duplicate Without Clones - Creates an independent instance of the source selection at the same position in 3D. All clone connections are disrupted within the duplicate.
  • Duplicate Mirror X/Y/Z - Creates an independent instance of the source selection, mirrored across the selected axis.
  • Duplicate Mirror X/Y/Z Flush - Creates an independent instance of the source selection, mirrored across the selected axis. This command also flushes the transformations from the subtree into the object nodes.

• Unshare - Removes a referenced connection. Changes made to one object no longer affect its former reference. Internal clones are preserved.

  • Unshare - Disrupts all clone connections from nodes in the selected subtree to other parts of the Scene Graph.
  • Unshare Selected Node - Disrupts only the clone connection of the selected node.
  • Unshare Subtree - Disrupts all clone connections in the selected subtree.

• Copy Transformation - Copies all transformation information from the selected node to the clipboard. A transformation contains information on the position and orientation of an object within 3D space. It also provides information on the position and orientation of the object's coordination system.

• Paste Transformation - Accesses paste options for transformations. Paste all transformation information, such as translation, rotation, scale, and pivot, or select one attribute to paste. Paste the pivot to apply the location and orientation from the object’s local coordinate system. Use Paste As Variant to paste a copy of a transformation as a variant on a selected node.

Copy/Paste Transform Variants

• Copy Transform Variants - Copies all transform variants of a selected node.

• Paste Transform Variants - Pastes all copied transform variants to a selected node.

Copy UVs

Copies UV coordinates from a selected geometry node.

Paste UVs

Pastes the copied UV coordinates to one or multiple selected geometry nodes. Pasting is only successful if the source and target have the same number of vertices. In case they have different numbers, an error message is displayed in the Terminal.

Lock/Unlock

Nodes can be locked, so they and their children cannot be modified anymore. A locked node is indicated in the Scene Graph by its icon . In the Render Window, when a selected node is locked, the bounding box, wireframe, and transformation handle are gray.

Group

Use these options in the Edit menu to group objects.

• Group by Material - Groups objects by their applied materials into new nodes.

  Important:

  This rearranges the Scene Graph structure.

• Group Selection - Moves selected objects into a new node. (Ctrl+Shift+G)

Show Optimize Module

Opens the Optimize Module to optimize the scene and increase rendering performance. All optimization processes are applied to the selected nodes and their children.