Mesh Deform binding to a cage object with modifiers is unreliable. #46944

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Alexander Gavrilov · 2015-12-09T14:00:51+01:00

Alexander Gavrilov commented

2015-12-09 14:00:51 +01:00

System Information

Fedora 21

Blender Version

Broken: up to and including 2.76b

Short description of error

Binding Mesh Deform to a cage dynamically generated with Solidify and Displace modifiers is unreliable, unless an obscure workaround involving creating a copy of the cage and applying the modifiers is used. I found the workaround in a relatively old tutorial, so the problem likely existed for a long time.

Exact steps for others to reproduce the error

This file demonstrates the setup and effects of various binding methods: test-cage.blend

Cage objects:

cage (wireframe): single layer quad mesh with cloth simulation, followed by solidify and displace modifiers.
cage-copy: copy of cage with all modifiers applied, to be used for binding.

Visible 'cloth' objects (all using the same mesh, produced by applying the solidify and discarding displace of the cage mesh):

cloth1 (green): bind done at precision 5 to cage-copy, then the object reference changed to cage in the modifier settings.
cloth2 (red): bind done at precision 5 directly to cage.
cloth3 (purple, layer initially hidden): bind done at precision 6 to cage.

If you step time to run the cloth simulation, cloth1 follows the cage as intended, cloth2 doesn't move, and cloth3 follows but also noticeably swells to fill the cage.

Also, the workaround itself seems to be exploiting a bug, since the Object field in settings is greyed out after bind, but still can be changed; not that it is necessarily bad given the issue at hand.

**System Information** Fedora 21 **Blender Version** Broken: up to and including 2.76b **Short description of error** Binding Mesh Deform to a cage dynamically generated with Solidify and Displace modifiers is unreliable, unless an obscure workaround involving creating a copy of the cage and applying the modifiers is used. I found the workaround in a relatively old tutorial, so the problem likely existed for a long time. **Exact steps for others to reproduce the error** This file demonstrates the setup and effects of various binding methods: [test-cage.blend](https://archive.blender.org/developer/F265125/test-cage.blend) Cage objects: - **cage** (wireframe): single layer quad mesh with cloth simulation, followed by solidify and displace modifiers. - **cage-copy**: copy of cage with all modifiers applied, to be used for binding. Visible 'cloth' objects (all using the same mesh, produced by applying the solidify and discarding displace of the cage mesh): - **cloth1** (green): bind done at precision 5 to cage-copy, then the object reference changed to cage in the modifier settings. - **cloth2** (red): bind done at precision 5 directly to cage. - **cloth3** (purple, layer initially hidden): bind done at precision 6 to cage. If you step time to run the cloth simulation, cloth1 follows the cage as intended, cloth2 doesn't move, and cloth3 follows but also noticeably swells to fill the cage. Also, the workaround itself seems to be exploiting a bug, since the Object field in settings is greyed out after bind, but still can be changed; not that it is necessarily bad given the issue at hand.

Alexander Gavrilov commented

2015-12-09 14:00:51 +01:00

Changed status to: 'Open'