Delete geometry node

Deletes input geometry by group, entity number, bounding volume, primitive/point/edge normals, and/or degeneracy.

On this page

Using Delete
Parameters
- Number
- Bounding Volume
- Normal
- Degenerate
- Random
Locals
Examples

In addition to simply deleting unwanted parts of a model, this operator is useful for culling primitives from very dense geometry to speed up cooking of nodes downstream.

This operation can also delete profile groups (for example, 0.5 1.2-3.9) and mixed groups (for example, 0 0.5 4-12 1.2-3.9).

causing the remaining hierarchy to update. By deleting the root of a paste hierarchy, the whole hierarchy becomes undone.

Using Delete ¶

Select the object at the object level or components of the object at the geometry level.
Click the Delete tool on the Modify tab.

Note

This tool is mapped to the ⌦ Del key.

Parameters ¶

Note

This node deletes entries in the Group field and any polygons matching the criteria in the Operation, Entity, and Geometry Type fields.

Group

Subset of the input geometry to delete, in addition to those parts matching the other criteria.

Operation

How the rules below affect the geometry.

Delete selected

Delete the geometry that matches the rules below.

Delete non-selected

Delete the geometry that doesn’t match the rules below.

Entity

Points

Delete points.

Primitives

Delete primitives.

Edges

Delete the points associated with each selected edge.

Geometry Type

Type of geometry to delete.

Number ¶

Enable

Turns on the controls for this tab and allows you to delete by point/primitive/edge numbers.

Operation

How to choose which points/primitives/edges to delete.

Delete by pattern

Delete points/primitives whose numbers match a pattern string. Edges use primitive numbers.

Delete by range

Delete points/primitives whose numbers fall within a certain range, and/or delete every few points/primitives. Edges use primitive numbers.

Delete by expression

Evaluate an expression for each point/primitive and delete it if the expression returns true.

Filter Expression

(When Operation is “Delete by expression”) Evaluates this expression for every point/primitive and, if the expression is true, deletes the point/primitive.

You can use all the local variables of the Point and Primitive operations in this expression.

Pattern

(When Operation is “Delete by pattern”) Deletes points/primitives/edges that match this pattern.

Start/End

(When Operation is “Delete by range”) The range of geometry to be deleted.

Select of

(When Operation is “Delete by range”) Deletes every (number in the left field) points/primitives for every (number in the right field) points/primitives in the input. Edges are ranged by primitive numbers.

Bounding Volume ¶

Enable

Turns on the controls for this tab and allows you to delete entities inside a bounding volume.

Bounding Type

Shape of bounding volume.

Bounding box

Delete points/primitives/edges within a bounding box.

Bounding sphere

Delete points/primitives/edges within a bounding sphere.

Size

Size of the bounding volume.

Center

Center of the bounding volume.

Normal ¶

Enable

Turns on the controls for this tab and allows you to delete entities based on their normals.

Direction

Delete points/primitives/edges with normals pointing in this direction. Use the Spread angle

Spread Angle

Angle of deviation from specified direction for which geometry will be deleted.

Backface from

Specifies a camera. Polygons that face away from the camera are deleted.

Degenerate ¶

Enable

Turns on the controls for this tab and allows you to delete degenerate entities.

Delete Degenerate Primitives

Remove repeated references of points and vertices within faces and then delete all degenerate primitives.

Delete Zero-Area Faces

Delete faces with surface area less than the tolerance. For area, the tolererance is squared, so the provided tolerance is the side of a square quad that will not be deleted.

Treat Open Faces as Closed

Delete open faces with perimeter less than the tolerance.

Tolerance

The length to consider zero area or zero perimeter. For area, this is squared, so becomes the side of the smallest square that would be considered zero area.

Random ¶

Enable

Turns on the controls for this tab and allows you to delete elements based on a random value computed on each element.

Global Seed

The initial seed used to determine which elements are deleted.

Use Seed Attribute

Whether to use an integer attribute on the specified elements that is used in place of the element number when determining whether an element is deleted.

Seed Attribute

An integer attribute on the specified elments that is used in place of the element number when determining whether an element is deleted. For edges, the point numbers or the attribute value on both points is combined and used to determine the seed for each edge. For vertices, the point number or attribute value on the point that the vertex belongs to is used to determine the seed for each vertex.

Percent

The approximate percentage of elements to remove (or keep if Operation is Delete Non-Selected). The Global Seed is combined with the Seed Attribute or element number if Use Seed Attribute is disabled, to determine a seed value for each element. This seed value is then used to find a value between 0 and 100 for each element, and any element with a value less than or equal to the Percent is included in the group.

Delete Unused Groups

Remove any groups that are left empty after deleting points/primitives/edges.

Keep Points

By default, if you delete a lot of polygons, the points that are no longer in use are also deleted. Turning on Keep Points will keep these points floating in space.