Compute Geometry Bounds

Computes bounding boxes for the input geometries (and cache cooking for future intersection tests)

Compute Geometry Bounds is an Immediate Node that takes all Prims in the input bundle and computes their Axis Aligned Bounding Boxes (or AABB).

The output bundle will contain a pass-through copy of the input bundle with new attributes added (or overwriting them if they already exists with the same name). The new bboxMinCorner and bboxMaxCorner are world space corners of the bounding box for each prim.

This node will also compute the hash of mesh data and cooking data structures needed for most intersection queries, like the ones done by:

• Compute Geometry Penetrations

• Compute Geometry Overlaps

• Compute Mesh Intersecting Faces.

• Generate Geometry Contacts

Installation

To use this Node, you must enable omni.physx.graph in the Extension Manager.

Inputs

Name	Type	Description	Default
execIn	execution	Input execution
primsBundle	bundle	The prims of interest. It must be a bundle with one or more prim children. Currently only meshes prim are supported (sourcePrimType == ‘Mesh’). From each Mesh prim child reads: - ‘sourecePrimPath’ - ‘sourcePrimType’ - ‘points’ - ‘faceVertexIndices’ - ‘faceVertexCounts’ - ‘worldMatrix’ and (optionally) ‘meshHash’, ‘physics:approximation’

Outputs

Name	Type	Description	Default
execOut	execution	Output execution
primsBundle	bundle	The same bundle passed as input with the following attributes added: - bboxMaxCorner - bboxMinCorner - meshHash

Note

Computation is done in parallel so it’s better feeding all needed prims to a single node than creating many nodes with a single prim input if possible.

Cooking data is cached in memory and on disk to avoid expensive re-computation, by checking the mesh hash.

This approach improves performance of all other Compute and Generate Immediate nodes, if this node is executed at the very start of a longer multi-step OmniGraph computation.

Important

Immediate nodes currently only support Mesh Prims, and not Shape prims.

Demos:

Several demo scenes can be accessed through the physics demo scenes menu option (Window > Simulation > Physics / Demo Scenes).

This will enable a Physics Demo Scenes window.

A demo using this node is labeled Objects de-penetration: