Generates groups of points or primitives according to various criteria.
Elements can occur in more than one group. Groups are used in many parts of the op Editor to specify which portion/s of input geometry you wish a op to act upon.
You can also create ordered groups. To do so, check the Ordered button.
This op is very powerful and is ideal for combining geometry that is similar. For example, all the primitive geometry of a group of door structures for a three-dimensional architectural model could be grouped together and consequently scaled and re-sized together using a Transform node. Works in conjunction with most filter nodes.
Group name specifiers become very powerful when you use pattern matching in your group specifiers.
Using Group Geometry
Select the points or primitives you want to group.
Click the
Group Geometry tool on the Model tab of the shelf.
Enter a Group Name in the operation controls toolbar or the parameter editor.
Tip
When using the hotkeys to select edges to group, press Tab once the selection is complete (instead of Enter), and select the Group Geometry operation in the tab menu.
Inputs
| Source geometry | The geometry on which to create the groups. |
| Bounding object | Bounding geometry. (Only works for point groups when selecting by bounding geometry.) Accepts all geometry. |
Parameters
Create
| Group Name | The name of the group to create. |
| Entity | Whether to create a primitive or point group. |
| Geometry Type | What sort of primitives to allow in the group. |
Number
| Enable | Enable grouping by number. |
| Create Ordered | Orders the points/primitives in the group in the order they are entered. Useful when skinning. |
| Operation | Group by a pattern, a range, or an expression. |
| Filter Expression | This is evaluated for every point or primitive. If it is true, the element is added to the group. It supports all the local variables of the Point and Primitive operations. Note: Points and primitives that match the expression will be in the final group regardless of the other tabs. |
| Pattern | Enter the pattern to be grouped. |
| Start | The start of the range to be grouped. |
| End | The end of the range to be grouped. |
Select _ of _
| Group every # of # primitives/points. |
Bounding
| Enable | Enable grouping by bounding volume. |
| Bounding Type | Shape of bounding volume. |
| Size | Size of bounding volume. |
| Center | Center of bounding volume. |
| Iso | Iso surface of volume to do the grouping with. Points whose volume value are less than this will be grouped. A value of 0 is good for SDF volumes. For fog volumes, use a value of 0.5 and turn on Invert Volumes for best results. |
| Invert Volume | Inverts sense of being inside the volume. |
Normal
| Enable | Enable grouping by normal. |
| Direction | Normal direction to group by. |
| Spread Angle | Deviation from the direction to allow in the group. |
| Backface from | Groups primitives facing away from this object. |
| Non-Planar Polys | Groups polygons that are non-planar given the tolerance. |
Note: Polygons that are non-planar will be added to the group regardless of the other tabs.
Edges
| Enable | Enables edge grouping. |
Note: Points and primitives that match the edge grouping rules will be in the final group regardless of the other tabs.
| Edge Angle | Groups primitives with this angle between them. |
| Edge Depth | Number of edges away from the points in Point Group. |
| Point Group | Points around which group is centered. |
| Unshared Edges | Groups all points/primitives with unshared edges. |
| Create Boundary Groups | Create groups containing surface boundary points. |
Combine
Combines different groups based on boolean operators.
| Combine Entity | The type of group on which to operate. While it can usually be determined from the given groups, this parameter is useful to resolve ambiguous cases. |
| Group | This section allows you to create a new group out of existing groups. Enter the group to operate on or create in the first field and the name of the existing group in the field on the other side of the buttons. You can either include the contents the other group by selecting |
Equals or everything that is not the other group by selecting 
Equals all but. Use the fields below to combine additional groups.
Edit
| Rename | Renames an existing group to something else. When renaming groups, you can use wildcards to rename several groups that match the specified pattern. For more information about the patter substitution rules, please see Attrib String Edit. |
| Group | Group to rename. |
| New Name | New name of group. |
| Convert | Converts between point and primitive groups. |
| Convert Type | Type of conversion. |
| Group | Group to convert. |
| Convert Name | New name of the converted group. Leave this empty to keep the name of the original group. |
| Preserve Original | Preserves original geometry. |
| Only Include Primitives with all Points in Group | When converting from a point group to a primitive group, this option allows only primitives that have all of their points in the original point group to be included in the resulting primitive group. |
| Delete | Deletes an existing group. |
| Group | Group to delete. |