Thread by @PierreTerdiman

I don't know which flavor of "dynamic meshes" you're talking about so let's go back to the basics and define some terms.

A MESH has vertices (GEOMETRY) and triangle indices (TOPOLOGY).

It can have a POSE (a.k.a. TRANSFORM) defining its position/rotation/scale in the world.

A STATIC MESH is one whose geometry, topology and pose are constant.

A DYNAMIC MESH is one whose geometry and topology are constant, but the pose varies over time.

This is similar to static / dynamic actors in physics engines.

A DEFORMABLE MESH is one whose geometry varies over time. The topology is constant. The pose can vary.

For lack of a better word, a PROCEDURAL MESH is one whose geometry AND topology can change over time. The pose can vary as well.

Typical soft bodies and cloth are deformable meshes, not "dynamic meshes".

Marching cubes are procedural meshes, not "dynamic meshes".

Rigid bodies with a mesh collision shape, e.g. using "pmaps" or SDFs, are dynamic meshes.

At least that's my nomenclature.

Why these distinctions matter:

- both static and dynamic meshes have a static BVH.

- deformable meshes have a dynamic BVH that can be "refit" (easy case).

- procedural meshes have a dynamic BVH that must be properly updated / rebuilt (hard case).