Dynamically bound mesh deform modifiers fail to update viewport on object transformation of deformer #71412

New Issue

Nathan Vasil · 2019-11-07T19:26:02+01:00

Nathan Vasil commented

2019-11-07 19:26:02 +01:00

System Information
Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: GeForce GTX 1070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 432.00

Blender Version
Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-11-06 20:48, hash: 85637311c2
Also broken: Blender 2.80 release
Worked: Blender 2.79b release

When you transform an object, Blender fails to update objects that depend on that object for purposes of dynamically bound mesh deform modifiers. This affects only viewport display; render displays properly (probably updating everything prior to rendering anyways?)

This also appears to be true with non-dynamically bound mesh deforms, although it's unclear whether regular binds should depend on transformation space, or if the fact that they do is a (different) bug-- I just figure regular mesh deforms operating in different spaces than their targets is unsupported.

Exact steps for others to reproduce the error

See attached .blend, made in 2.80 release, which demonstrates the bug and the workaround:

MDbug.blend

Cube at origin is being mesh deformed by Icosphere in wire display over it. Move Icosphere in object mode. Cube fails to update. (Enter then exit edit mode on Icosphere to trigger Cube to update and see how your object level transformation affected the dynamic mesh deform.)

Cube.001 and Icosphere.001 demonstrate the workaround. By parenting Icosphere.001 to a bone that triggers update of Cube.001 via a meaningless armature modifier, you can manipulate Icosphere.001 through the bone for real-time updating of the effects of your transformation.

**System Information** Operating system: Windows-10-10.0.18362 64 Bits Graphics card: GeForce GTX 1070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 432.00 **Blender Version** Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-11-06 20:48, hash: `85637311c2` Also broken: Blender 2.80 release Worked: Blender 2.79b release When you transform an object, Blender fails to update objects that depend on that object for purposes of dynamically bound mesh deform modifiers. This affects only viewport display; render displays properly (probably updating everything prior to rendering anyways?) This also appears to be true with non-dynamically bound mesh deforms, although it's unclear whether regular binds should depend on transformation space, or if the fact that they do is a (different) bug-- I just figure regular mesh deforms operating in different spaces than their targets is unsupported. **Exact steps for others to reproduce the error** See attached .blend, made in 2.80 release, which demonstrates the bug and the workaround: [MDbug.blend](https://archive.blender.org/developer/F7977555/MDbug.blend) Cube at origin is being mesh deformed by Icosphere in wire display over it. Move Icosphere in object mode. Cube fails to update. (Enter then exit edit mode on Icosphere to trigger Cube to update and see how your object level transformation affected the dynamic mesh deform.) Cube.001 and Icosphere.001 demonstrate the workaround. By parenting Icosphere.001 to a bone that triggers update of Cube.001 via a meaningless armature modifier, you can manipulate Icosphere.001 through the bone for real-time updating of the effects of your transformation.

Nathan Vasil commented

2019-11-07 19:26:02 +01:00

Added subscriber: @vasiln

Philipp Oeser commented

2019-11-07 20:26:12 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2019-11-07 20:26:12 +01:00

P1155: T71412_snippet



diff --git a/source/blender/modifiers/intern/MOD_meshdeform.c b/source/blender/modifiers/intern/MOD_meshdeform.c
index 408e38f43ab..21fdc010a1d 100644
--- a/source/blender/modifiers/intern/MOD_meshdeform.c
+++ b/source/blender/modifiers/intern/MOD_meshdeform.c
@@ -158,7 +158,7 @@ static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphConte
 {
   MeshDeformModifierData *mmd = (MeshDeformModifierData *)md;
   if (mmd->object != NULL) {
-    /* TODO(sergey): Do we need transform component here? */
+    DEG_add_object_relation(ctx->node, mmd->object, DEG_OB_COMP_TRANSFORM, "Mesh Deform Modifier");
     DEG_add_object_relation(ctx->node, mmd->object, DEG_OB_COMP_GEOMETRY, "Mesh Deform Modifier");
   }
 }

would make it update [as 2.79 did]

Still not sure if this is desired behavior [will read up on Dynamic Binding for a bit...]

[P1155: T71412_snippet](https://archive.blender.org/developer/P1155.txt) ``` diff --git a/source/blender/modifiers/intern/MOD_meshdeform.c b/source/blender/modifiers/intern/MOD_meshdeform.c index 408e38f43ab..21fdc010a1d 100644 --- a/source/blender/modifiers/intern/MOD_meshdeform.c +++ b/source/blender/modifiers/intern/MOD_meshdeform.c @@ -158,7 +158,7 @@ static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphConte { MeshDeformModifierData *mmd = (MeshDeformModifierData *)md; if (mmd->object != NULL) { - /* TODO(sergey): Do we need transform component here? */ + DEG_add_object_relation(ctx->node, mmd->object, DEG_OB_COMP_TRANSFORM, "Mesh Deform Modifier"); DEG_add_object_relation(ctx->node, mmd->object, DEG_OB_COMP_GEOMETRY, "Mesh Deform Modifier"); } } ``` would make it update [as 2.79 did] Still not sure if this is desired behavior [will read up on Dynamic Binding for a bit...]

Sybren A. Stüvel commented

2019-11-14 17:12:16 +01:00

Added subscriber: @dr.sybren