Weight Paint Gradient Tool doesn't consider Auto-Normalize #84651

New Issue

Demeter Dzadik · 2021-01-12T19:09:13+01:00

Demeter Dzadik commented

2021-01-12 19:09:13 +01:00

System Information
Operating system: Linux-5.4.0-7634-generic-x86_64-with-debian-bullseye-sid 64 Bits
Graphics card: GeForce RTX 2080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 440.100

Blender Version
Broken: version: 2.92.0 Alpha, branch: master, commit date: 2021-01-12 14:43, hash: c3b68fa7b1
Worked: Possibly never but I'm not sure.

Short description of error
Today I had a once in a lifetime opportunity to make use of the gradient tool in a weight painting case. And then it failed! It seems that when using the gradient tool in weight paint mode, the weights don't get normalized during the stroke.

Exact steps for others to reproduce the error
gradient_doesnt_auto_normalize.blend
Click and drag on the sphere. Notice that the influence of Bone2 wasn't subtracted from Bone1.

This tool is extremely rarely used so this is a small issue.

**System Information** Operating system: Linux-5.4.0-7634-generic-x86_64-with-debian-bullseye-sid 64 Bits Graphics card: GeForce RTX 2080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 440.100 **Blender Version** Broken: version: 2.92.0 Alpha, branch: master, commit date: 2021-01-12 14:43, hash: `c3b68fa7b1` Worked: Possibly never but I'm not sure. **Short description of error** Today I had a once in a lifetime opportunity to make use of the gradient tool in a weight painting case. And then it failed! It seems that when using the gradient tool in weight paint mode, the weights don't get normalized during the stroke. **Exact steps for others to reproduce the error** [gradient_doesnt_auto_normalize.blend](https://archive.blender.org/developer/F9561315/gradient_doesnt_auto_normalize.blend) Click and drag on the sphere. Notice that the influence of Bone2 wasn't subtracted from Bone1. This tool is extremely rarely used so this is a small issue.

Demeter Dzadik commented

2021-01-12 19:09:13 +01:00

Added subscriber: @Mets

blender-admin commented

2021-01-12 19:09:13 +01:00

#78558 was marked as duplicate of this issue

Falk David commented

2021-01-12 19:30:12 +01:00

Added subscriber: @filedescriptor

Falk David commented

2021-01-12 19:30:12 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'

Falk David commented

2021-01-12 19:30:12 +01:00

I can confirm the issue on 2.92.0 Alpha, branch: master, commit date: 2021-01-12 15:24, hash: 957e292c58.

I can confirm the issue on 2.92.0 Alpha, branch: master, commit date: 2021-01-12 15:24, hash: `957e292c58`.

Campbell Barton commented

2021-01-20 07:27:24 +01:00

Added subscriber: @ideasman42

Campbell Barton commented

2021-01-20 07:27:24 +01:00

Some background on this task.

The gradient tool has it's own logic for assigning vertex weights, so painting options aren't automatically available. *.
Supporting auto-normalize seems reasonable, and isn't a big project. See logic for OBJECT_OT_vertex_group_normalize_all.
We could check on supporting other paint options for gradient tool too, if this becomes a lot of work, we might consider sharing code-paths with paint code.

* we could rewrite this tool to use the same underlying logic as the weight paint tool, this is a much bigger task.

Some background on this task. - The gradient tool has it's own logic for assigning vertex weights, so painting options aren't automatically available. `*`. - Supporting auto-normalize seems reasonable, and isn't a big project. See logic for `OBJECT_OT_vertex_group_normalize_all`. - We could check on supporting other paint options for gradient tool too, if this becomes a lot of work, we might consider sharing code-paths with paint code. ---- `*` we could rewrite this tool to use the same underlying logic as the weight paint tool, this is a much bigger task.

Pratik Borhade commented

2021-01-20 10:56:57 +01:00

Added subscriber: @PratikPB2123

Pratik Borhade commented

2021-01-20 10:56:57 +01:00

@filedescriptor I never tried the operator auto normalize , could you please tell me what should be expected output for user in following case ??

@filedescriptor I never tried the operator `auto normalize` , could you please tell me what should be expected output for user in following case ??

Demeter Dzadik commented

2021-01-20 11:44:38 +01:00

After you've done the reproduction steps, you can go back to the Brush tool, and make a stroke with a very low brush strength like 0.00001. This will trigger the normalization, and the weights will be subtracted from Bone1 as expected.

This is also effectively the workaround to the issue.

After you've done the reproduction steps, you can go back to the Brush tool, and make a stroke with a very low brush strength like 0.00001. This will trigger the normalization, and the weights will be subtracted from Bone1 as expected. This is also effectively the workaround to the issue.

Pratik Borhade commented

2021-01-20 12:20:31 +01:00

@Mets ,So effect of bone 2 is not getting subtracted from bone 1 if gradient tool is used ( but it subtracts when we do the same with brush/draw tool and same should be the expected output for gradient tool as well) .
what is roll of auto - normalize here ?? , No idea what exactly it does.

@Mets ,So effect of bone 2 is not getting subtracted from bone 1 if `gradient tool` is used ( but it subtracts when we do the same with brush/draw tool and same should be the expected output for `gradient tool` as well) . what is roll of `auto - normalize` here ?? , No idea what exactly it does.

Demeter Dzadik commented

2021-01-20 12:26:32 +01:00

Auto-Normalize should make sure that all deforming weights on each individual vertex add up to 1.0 at all times. So, the influence of Bone2 is expected to be subtracted from the influence of Bone1, as a result of making sure that their combined weights add up to 1.0 on each vertex.

This is used in weight painting to make sure that the visual colors actually represent the amount of deformation coming from each bone. It is a bit like a user preference - different people will have it on or off, but one person wouldn't change it while working.

Auto-Normalize should make sure that all deforming weights on each individual vertex add up to 1.0 at all times. So, the influence of Bone2 is expected to be subtracted from the influence of Bone1, as a result of making sure that their combined weights add up to 1.0 on each vertex. This is used in weight painting to make sure that the visual colors actually represent the amount of deformation coming from each bone. It is a bit like a user preference - different people will have it on or off, but one person wouldn't change it while working.

Pratik Borhade commented

2021-01-21 07:41:15 +01:00

@Mets , I appreciate your help .
I observed , for brush tool If auto normalize is turned on then only weight of bone2 is getting subtracted from bone1 . If auto normalize is unchecked then it won't subtract.
where for gradient tool same behaviour(weights don't get subtracted) is observed whether auto normalize of checked or unchecked .
So expected result is , when auto- normalize is checked , weights should be subtracted.
Let me know if I am proceeding in right way or not ?

@Mets , I appreciate your help . I observed , for `brush tool` If auto normalize is turned on then only weight of bone2 is getting subtracted from bone1 . If auto normalize is unchecked then it won't subtract. where for `gradient tool` same behaviour(`weights don't get subtracted`) is observed whether `auto normalize` of **checked** or **unchecked** . So expected result is , when auto- normalize is checked , weights should be subtracted. Let me know if I am proceeding in right way or not ?

Demeter Dzadik commented

2021-01-21 11:00:20 +01:00

Yep, that sounds correct! So it seems that the gradient tool is ignoring the auto-normalize setting.

Luciano Muñoz Sessarego commented

2021-01-21 11:05:39 +01:00

Added subscriber: @LucianoMunoz

Luciano Muñoz Sessarego commented

2021-01-21 11:05:39 +01:00

I think none of the operators obey auto-normalize, as its only a painting setting, i would appreciate it that you could set a global auto-normalize for every function

Pratik Borhade commented

2021-01-22 05:40:03 +01:00

Sure @LucianoMunoz . I will try .

Jer Bot commented

2021-01-24 03:18:44 +01:00

Added subscriber: @JerBot

Jer Bot commented

2021-01-24 03:18:44 +01:00

In #84651#1097867, @LucianoMunoz wrote:
I think none of the operators obey auto-normalize, as its only a painting setting, i would appreciate it that you could set a global auto-normalize for every function

I second this!
Would save me extra steps, or save me from relying on skin weighting addons (which usually have an auto-normalize option for their operations).

> In #84651#1097867, @LucianoMunoz wrote: > I think none of the operators obey auto-normalize, as its only a painting setting, i would appreciate it that you could set a global auto-normalize for every function **I second this!** Would save me extra steps, or save me from relying on skin weighting addons (which usually have an auto-normalize option for their operations).

Pratik Borhade self-assigned this 2021-01-28 15:44:27 +01:00

Pratik Borhade commented

2021-02-01 16:43:06 +01:00

hey @ideasman42 and @LucianoMunoz , can you take a time and review the patch I submitted D10239 .

hey @ideasman42 and @LucianoMunoz , can you take a time and review the patch I submitted [D10239](https://archive.blender.org/developer/D10239) .

blender-admin commented

2021-02-13 11:13:27 +01:00

This issue was referenced by 32660201ac

This issue was referenced by 32660201acaa1138c0fed6ef3fa38f69daa3dac3

Campbell Barton commented

2021-02-13 11:18:55 +01:00

Changed status from 'Confirmed' to: 'Resolved'