PhysxTriangleMeshSimplificationCollisionAPI#

Quadric mesh simplification cooking parameters for a Mesh collider with physics:approximation meshSimplification. Cooking inputs only; nothing here is verified.

  • Applies to: Gprim

  • Requires on the same prim: PhysicsCollisionAPI

  • Read only when listed in usd-schemas.

What USD population writes#

Every declared attribute of an applied collision API is published at its resolved value; both columns land as their raw fallbacks when unauthored. No derivation.

Columns#

Raw fallback is the USD schema value. Producer writes is what ovstage population puts in the column for a USD stage. Parser default applies on the consumer when the column is absent, in stage units. diverges means writing the raw fallback literally parses differently from omitting the column (the parser default): USD population may well publish that very value for an unauthored attribute, so the marker is about the column being present, not about its value.

Column

Type

Units

Raw fallback

Producer writes

Parser default

If absent

physxTriangleMeshSimplificationCollision:metric

float32

none

0.55

resolved USD value (authored, else raw fallback)

0.55

0.55 (TriangleMeshCookingParams::simplificationMetric). Unauthored preserves the existing value; no clamping.

physxTriangleMeshSimplificationCollision:weldTolerance

float32

length

-inf

resolved USD value (authored, else raw fallback)

-FLT_MAX

-FLT_MAX: no vertex welding. A published -inf (the raw fallback) is also negative and has the same effect. A NaN is rewritten to -FLT_MAX unconditionally.

Interactions#

  • PhysicsMeshCollisionAPI: Read by parseTriangleMeshSimplificationCookingExt only for descriptor kind meshSimplification, which also sets TriangleMeshCookingParams::mode to eQUADRIC_SIMPLIFICATION. No usd-schemas gate: the columns are read whenever they exist on the collider.

  • PhysicsRigidBodyAPI: On a dynamic body meshSimplification is silently promoted to convexHull (see PhysicsMeshCollisionAPI) and these columns are then never read.

Notes#

  • Cooking APIs on a Mesh cannot be verified by the generated tests: the parameters only change the cooked PxTriangleMesh, which exposes no getter for them, and the builder writes no mesh arrays.