Applying Data Transfer Modifier - only the active Shape Key is taken into account #103929

New Issue

cmto · 2023-01-17T00:04:43+01:00

cmto commented

2023-01-17 00:04:43 +01:00

System Information
Operating system: Win 10 x64
Graphics card: 3080 TI

Blender Version
Broken: 3.3.2, 86abbf7176, master, 2022-11-28
Worked: ??

When applying data transfer modifier to an object (to transfer vertex groups), it only takes into account the selected shape key, not all others too.

Example:

Download test Blend:
datatransfer_shapekeys.blend

This is the cube's vertex group:

Plane is moved down by shape key "Key 1". All looks good in the viewport, this is how the vertex group should look when you apply it:

But if the 'Basis' shape key is selected instead of 'Key 1' when you apply the modifier, it ignores Key 1.

See how the position of the vertex weight is off as compared to the first picture, as if Key 1 were disabled.

But if you were to have Key 1 selected when you apply the modifier, it works as expected:

This is troublesome with objects that have many shape keys, all with different influences on the affected area. When you apply the modifier, it should take into account every active shape key.

This gets even less predictable if you have multiple shapekeys besides the Basis shapekey.
Here I have two (both with 0.5 weight).
You get different results selecting Key 1 or Key 2 and none look like what you had in the viewport:
datatransfer_shapekeys_multiple.blend

**System Information** Operating system: Win 10 x64 Graphics card: 3080 TI **Blender Version** Broken: 3.3.2, 86abbf717691, master, 2022-11-28 Worked: ?? When applying data transfer modifier to an object (to transfer vertex groups), it only takes into account the selected shape key, not all others too. Example: Download test Blend: [datatransfer_shapekeys.blend](https://archive.blender.org/developer/F14154460/datatransfer_shapekeys.blend) This is the cube's vertex group: ![image.png](https://archive.blender.org/developer/F14154959/image.png) Plane is moved down by shape key "Key 1". All looks good in the viewport, this is how the vertex group should look when you apply it: ![image.png](https://archive.blender.org/developer/F14154462/image.png) But if the 'Basis' shape key is selected instead of 'Key 1' when you apply the modifier, it ignores Key 1. ![image.png](https://archive.blender.org/developer/F14154470/image.png) See how the position of the vertex weight is off as compared to the first picture, as if Key 1 were disabled. ![image.png](https://archive.blender.org/developer/F14154466/image.png) But if you were to have Key 1 selected when you apply the modifier, it works as expected: ![image.png](https://archive.blender.org/developer/F14154477/image.png) This is troublesome with objects that have many shape keys, all with different influences on the affected area. When you apply the modifier, it should take into account every active shape key. This gets even less predictable if you have multiple shapekeys besides the `Basis` shapekey. Here I have two (both with 0.5 weight). You get different results selecting `Key 1` or `Key 2` and none look like what you had in the viewport: [datatransfer_shapekeys_multiple.blend](https://archive.blender.org/developer/F14171447/datatransfer_shapekeys_multiple.blend)

cmto commented

2023-01-17 00:04:43 +01:00

Added subscriber: @CHARLES-MURRAY

Philipp Oeser commented

2023-01-17 11:05:39 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2023-01-17 11:05:39 +01:00

#90276 (ShapeKey does not "see" modified Vertex Group (e.g. proximity modifier, dynamic paint)) might be related, needs a bit more checking though.

NOTE: in 3.5 there also seems to be a bug (in that if you select Key 1 and then apply the Data Transfer modifier, you seem to loose the shapekey shape alltogether)

#90276 (ShapeKey does not "see" modified Vertex Group (e.g. proximity modifier, dynamic paint)) might be related, needs a bit more checking though. NOTE: in 3.5 there also seems to be a bug (in that if you select `Key 1` and then apply the Data Transfer modifier, you seem to loose the shapekey shape alltogether)

Philipp Oeser commented

2023-01-17 12:38:07 +01:00

In #103929#1475383, @lichtwerk wrote:
NOTE: in 3.5 there also seems to be a bug (in that if you select Key 1 and then apply the Data Transfer modifier, you seem to loose the shapekey shape alltogether)

I reported this separately, see #103937 (Regression: applying NonGeometrical modifiers (UVProject, DataTransfer, ...) looses shape key data)

> In #103929#1475383, @lichtwerk wrote: > NOTE: in 3.5 there also seems to be a bug (in that if you select `Key 1` and then apply the Data Transfer modifier, you seem to loose the shapekey shape alltogether) I reported this separately, see #103937 (Regression: applying NonGeometrical modifiers (UVProject, DataTransfer, ...) looses shape key data)

Philipp Oeser commented

2023-01-18 10:28:16 +01:00

So first intuition was to use geometry nodes instead as a workaround:

geometrynodes_shapekeys.blend

But then again, you cannot apply that modifier with shapekeys...
Off to a closer look now...

So first intuition was to use geometry nodes instead as a workaround: [geometrynodes_shapekeys.blend](https://archive.blender.org/developer/F14171086/geometrynodes_shapekeys.blend) But then again, you cannot apply that modifier with shapekeys... Off to a closer look now...

Philipp Oeser commented

2023-01-18 12:16:27 +01:00

Changed status from 'Needs Triage' to: 'Needs Developer To Reproduce'

Philipp Oeser commented

2023-01-18 12:16:27 +01:00

Added subscribers: @mont29, @ideasman42, @JosephEagar, @dr.sybren

Philipp Oeser commented

2023-01-18 12:16:27 +01:00

Hm, so after a bit of digging, I found that this has its origins way back in 798e0b02c0

Since above commit, the selected shapekey is "applied fully" during create_applied_mesh_for_modifier (if you can apply a modifier with shapekeys at all -- only eModifierTypeType_NonGeometrical can) via BKE_keyblock_convert_to_mesh.

There have been a couple of related commits (even though these dont really affect the behavior):

This gets even less predictable if you have multiple shapekeys besides the Basis shapekey.
Here I have two (both with 0.5 weight).
You get different results selecting Key 1 or Key 2 and none look like what you had in the viewport:
datatransfer_shapekeys_multiple.blend

Calling create_applied_mesh_for_modifier with both use_virtual_modifiers & build_shapekey_layers as true fixes the issue (but that in return results in #97758, see above)

I would like input from developers that touched this area:

CC @ideasman42
CC @JosephEagar
CC @dr.sybren
CC @mont29

Hm, so after a bit of digging, I found that this has its origins way back in 798e0b02c0 Since above commit, the selected shapekey is "applied fully" during `create_applied_mesh_for_modifier` (if you can apply a modifier with shapekeys at all -- only `eModifierTypeType_NonGeometrical` can) via `BKE_keyblock_convert_to_mesh`. There have been a couple of related commits (even though these dont really affect the behavior): - 929a210608 - 65c5ebf577 This gets even less predictable if you have multiple shapekeys besides the `Basis` shapekey. Here I have two (both with 0.5 weight). You get different results selecting `Key 1` or `Key 2` and none look like what you had in the viewport: [datatransfer_shapekeys_multiple.blend](https://archive.blender.org/developer/F14171447/datatransfer_shapekeys_multiple.blend) Calling `create_applied_mesh_for_modifier` with both `use_virtual_modifiers` & `build_shapekey_layers` as `true` fixes the issue (but that in return results in #97758, see above) I would like input from developers that touched this area: CC @ideasman42 CC @JosephEagar CC @dr.sybren CC @mont29

Philipp Oeser changed title from ~~Data Transfer Modifier - Shape Keys Not Counted Unless Selected~~ to Applying Data Transfer Modifier - only the active Shape Key is taken into account

2023-01-18 12:57:55 +01:00

Philipp Oeser removed the

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Applying Data Transfer Modifier - only the active Shape Key is taken into account #103929