Regression: Sculpting using alpha brushes is slower in 3.2 than 3.1 #100379

New Issue

Tomek Gubala · 2022-08-12T22:34:55+02:00

Tomek Gubala commented

2022-08-12 22:34:55 +02:00

System Information
Operating system: Windows-10-10.0.19043-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 2060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 512.95

Blender Version
Broken: version: 3.2.2, branch: master, commit date: 2022-08-02 18:15, hash: bcfdb14560
Broken: version: 3.2.0, branch: master, commit date: 2022-06-08 10:22, hash: e05e1e3691
Worked: version: 3.1.2, branch: master, commit date: 2022-03-31 17:40, hash: cc66d1020c

Short description of error
Significant slowdown in sculpting when using "alpha brushes" with images to sculpt detail on high poly mesh

Exact steps for others to reproduce the error
0. Download blend file and provided alpha image. Place both in the same folder

Open provided blend file
Switch to modifiers tab
Add "subdivision surface" modifier
Switch to simple and set "levels viewport" to 5
Apply modifier
Add "Multiresolution" modifier.
Click subdivide until Sculpt/Render reaches 5
This creates object with 6+ mln faces to sculpt
Start sculpting with provided brush.

In 3.1.2 as long as brush is covering small area, it's very responsive. Once it gets bigger during dragging, there is a slowdown, but each next stroke goes back to being responsive as long as brush area is small. In 3.2 performance is very slow from the beginning.
First version I see this in is 3.2.0 and it continues to current release 3.2.2

alpha brush slow.blend

2022-08-12 22-12-53.mkv

**System Information** Operating system: Windows-10-10.0.19043-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 2060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 512.95 **Blender Version** Broken: version: 3.2.2, branch: master, commit date: 2022-08-02 18:15, hash: `bcfdb14560` Broken: version: 3.2.0, branch: master, commit date: 2022-06-08 10:22, hash: `e05e1e3691` Worked: version: 3.1.2, branch: master, commit date: 2022-03-31 17:40, hash: `cc66d1020c` **Short description of error** Significant slowdown in sculpting when using "alpha brushes" with images to sculpt detail on high poly mesh **Exact steps for others to reproduce the error** 0. Download blend file and provided alpha image. Place both in the same folder 1. Open provided blend file 2. Switch to modifiers tab 3. Add "subdivision surface" modifier 4. Switch to simple and set "levels viewport" to 5 5. Apply modifier 6. Add "Multiresolution" modifier. 7. Click subdivide until Sculpt/Render reaches 5 8. This creates object with 6+ mln faces to sculpt 9. Start sculpting with provided brush. In 3.1.2 as long as brush is covering small area, it's very responsive. Once it gets bigger during dragging, there is a slowdown, but each next stroke goes back to being responsive as long as brush area is small. In 3.2 performance is very slow from the beginning. First version I see this in is 3.2.0 and it continues to current release 3.2.2 [alpha brush slow.blend](https://archive.blender.org/developer/F13373241/alpha_brush_slow.blend) ![brush.png](https://archive.blender.org/developer/F13373245/brush.png) [2022-08-12 22-12-53.mkv](https://archive.blender.org/developer/F13373248/2022-08-12_22-12-53.mkv)

Tomek Gubala commented

2022-08-12 22:34:55 +02:00

Added subscriber: @VGT

Tomek Gubala commented

2022-08-12 22:36:54 +02:00

Polycount to encounter this issue might be dependent on hardware capabilities, so it might be worth to tinker with numbers in step 4 and 7. Go lower or higher depending on hardware limitations.

Tomek Gubala commented

2022-08-12 22:51:24 +02:00

Image is 2k 16-bit, which might be a bit overkill, but lowering it to 8-bit and 1k or even smaller doesn't change anything, so it does not seems to be related to image quality.

Omar Emara commented

2022-08-15 13:40:42 +02:00

Added subscriber: @OmarEmaraDev

Omar Emara commented

2022-08-15 13:40:42 +02:00

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

Omar Emara commented

2022-08-15 13:40:42 +02:00

I can reproduce the slow down between 3.1 and 3.2. The flame graphs are as follows. Let me know if you need a bisect.

3.1:

3.2:

I can reproduce the slow down between 3.1 and 3.2. The flame graphs are as follows. Let me know if you need a bisect. 3.1: ![20220815-133144.png](https://archive.blender.org/developer/F13387160/20220815-133144.png) 3.2: ![20220815-133322.png](https://archive.blender.org/developer/F13387159/20220815-133322.png)

Omar Emara changed title from ~~High poly mesh sculpt slow when using alpha brushes~~ to Regression: Sculpting using alpha brushes is slower in 3.2 than 3.1

2022-08-15 13:41:49 +02:00

blender-admin commented

2022-08-16 02:13:45 +02:00

This issue was referenced by f80f600b8e

This issue was referenced by f80f600b8e326639ea37bda1b4b85c382f39e683

Joseph Eagar commented

2022-08-16 02:15:10 +02:00

Changed status from 'Confirmed' to: 'Resolved'

Joseph Eagar closed this issue

2022-08-16 02:15:10 +02:00

Joseph Eagar self-assigned this 2022-08-16 02:15:10 +02:00

blender-admin commented