The problem was that the particle system modifier was reading ob->derivedDeform
during modifier stack evaluation. Due to the mesh -> DM conversion this was no
longer set leading to wrong results.
In fact we don't really need the deformed mesh, just the original mesh topology
for face/poly index remapping. So the solution is to use that instead.
This fix applying the following modifiers:
* Boolean (working already)
* Array
* Mesh Deform
* Surface Deform
* Vertex Weight Proximity
This function was to return evaluated mesh. So it should get the evaluated
object at all times. So in this case it makes more sense to simply pass the
depsgraph (or in this case the ModifierEvalContext that contains both the
depsgraph and the flag.
Solution discussed with Bastien Montagne.
The modifier is still quite slow; this could be due to caches being written
to a CoW datablock instead of the original one. More investigation is
needed.
There are a few places where DerivedMesh is still used, most notably
when calling the (not yet ported) cloth simulation. There is also still
the use of Object.derivedDeform and Object.derivedFinal. Those places are
marked with a TODO.
Some functions in the editors module were copied to accept Mesh. Those
already had 'mesh' in the name; the copies are suffixed with '__real_mesh'
for easy renaming later when the DM-based functionality is removed.
This flag is copied when converting between DM and Mesh.
This flag is set to true in get_mesh(), to mimick the behaviour of
CDDM_from_mesh_ex. This is necessary for the particle system to work
correctly.
Two things to indicate (which als apply before the DM → M port):
- Face count in the UI is not updated and stays at 0
- When planar mode is used, the result is inverted (mirrored along X)
compared to 2.79
Reviewers: sybren
Differential Revision: https://developer.blender.org/D3303
There is still an issue with the modified mesh not being updated until you
disable and re-enable the modifier. However, after that it'll now also work
while editing the deformation mesh.
The modifier performed the 'bind' operation not in the bind operator,
but delayed in the mesh evaluation. This saved the result in a CoW copy
instead of in the actual modifier data. The binding operator now follows
the same approach as Mesh Deform: it forces the modifiers to run on the
real (non-CoW) data, making it possible for the modifier to store the
binding data.
This commit also ports the usage of DerivedMesh to Mesh.
