Geometry Nodes: Experimental rigid body integration.

This is an exploration of how geometry nodes might be coupled with
rigid bodies and iterative simulations in general. It's a very
rough-and-ready implementation, not meant as a final version, but rather
to prove the possiblity and to find challenging areas where redesign is
needed.

The core additions are:
- Geometry nodes to flag points and/or instances as rigid bodies.
- Depsgraph integration to ensure the necessary order of operations
    between modifiers and rigid body pre/post simulation updates.
- Simple cache feature to store arbitrary geometry and loop back into
    the next iteration.

1 files changed, 1 insertions, 0 deletions

diff --git a/source/blender/modifiers/intern/MOD_meshdeform.c b/source/blender/modifiers/intern/MOD_meshdeform.c
index 5dac31ac1df..9309c205802 100644
--- a/source/blender/modifiers/intern/MOD_meshdeform.c
+++ b/source/blender/modifiers/intern/MOD_meshdeform.c
@@ -672,6 +672,7 @@ ModifierTypeInfo modifierType_MeshDeform = {
     /* requiredDataMask */ requiredDataMask,
     /* freeData */ freeData,
     /* isDisabled */ isDisabled,
+    /* ensureDepsgraphNodes */ NULL,
     /* updateDepsgraph */ updateDepsgraph,
     /* dependsOnTime */ NULL,
     /* dependsOnNormals */ NULL,