Just selecting the IK Pose brush with more than one segment and/or smooth iterations heavily slows down Blender when working with high poly sculpts #73172

New Issue

Frozen_Death_Knight · 2020-01-16T21:25:26+01:00

2020-01-16 21:25:26 +01:00

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce GTX 980/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 441.20

Blender Version
Broken: version: 2.83 (sub 0), branch: master, commit date: 2020-01-14 20:45, hash: 1ec08999b6
Worked: (optional)

Short description of error
The way it has been explained by Pablo, this brush isn't supposed to be used on high poly sculpts because of performance issues. That I understand. However, at the moment Blender begins to freeze and slow down heavily by just selecting the IK Pose brush with segments and/or smooth interactions active, which is a bit too much. Even if you know about the slowdowns beforehand you can still easily select the brush by accident and have your project slow down to a crawl. There should be a better solution that prevents the brush from slowing down Blender when it is not in use. Just having one segment like the older version of the brush doesn't behave like this.

Exact steps for others to reproduce the error

Have a fairly high poly mesh at around 1 million vertices selected in Sculpt Mode.
Select the IK Pose brush with segments and/or smooth iterations activated. You should get heavy slowdowns as shown in the video below.
Desktop 2020.01.16 - 21.12.24.01.mp4

**System Information** Operating system: Windows-10-10.0.18362-SP0 64 Bits Graphics card: GeForce GTX 980/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 441.20 **Blender Version** Broken: version: 2.83 (sub 0), branch: master, commit date: 2020-01-14 20:45, hash: `1ec08999b6` Worked: (optional) **Short description of error** The way it has been explained by Pablo, this brush isn't supposed to be used on high poly sculpts because of performance issues. That I understand. However, at the moment Blender begins to freeze and slow down heavily by just selecting the IK Pose brush with segments and/or smooth interactions active, which is a bit too much. Even if you know about the slowdowns beforehand you can still easily select the brush by accident and have your project slow down to a crawl. There should be a better solution that prevents the brush from slowing down Blender when it is not in use. Just having one segment like the older version of the brush doesn't behave like this. **Exact steps for others to reproduce the error** 1. Have a fairly high poly mesh at around 1 million vertices selected in Sculpt Mode. 2. Select the IK Pose brush with segments and/or smooth iterations activated. You should get heavy slowdowns as shown in the video below. [Desktop 2020.01.16 - 21.12.24.01.mp4](https://archive.blender.org/developer/F8282028/Desktop_2020.01.16_-_21.12.24.01.mp4)

Frozen_Death_Knight commented

2020-01-16 21:25:26 +01:00

Added subscriber: @Frozen_Death_Knight

Pablo Dobarro commented

2020-01-16 21:36:11 +01:00

Added subscriber: @PabloDobarro

Pablo Dobarro commented

2020-01-16 21:36:11 +01:00

This is because in the new version calculating the preview has the same cost as starting the brush, so each time you move the mouse it will calculate the weights of 1M vertices times the number of IK segments.
There are some solutions to this, like disabling the preview automatically if the computation is going to be too heavy to be done in real time or adding the manual option to disable the preview.

This is because in the new version calculating the preview has the same cost as starting the brush, so each time you move the mouse it will calculate the weights of 1M vertices times the number of IK segments. There are some solutions to this, like disabling the preview automatically if the computation is going to be too heavy to be done in real time or adding the manual option to disable the preview.

Frozen_Death_Knight commented

2020-01-16 21:58:20 +01:00

@PabloDobarro I think an automatic approach would be the best approach to this if you want the brush to be user friendly. It's a bit too much to ask new users especially to disable the preview manually to avoid this problem when they will likely do a lot of experimentation and attempts at working on higher poly meshes. Plus, it is going to get old having to disable and enable it every time you want to work with it when switching from high to low poly objects and vice versa.

That said, you could have a toggable option to always show the preview by overriding the automatic disable on higher poly meshes, but it should come with a warning about performance as a pop-up box or in the description itself.

@PabloDobarro I think an automatic approach would be the best approach to this if you want the brush to be user friendly. It's a bit too much to ask new users especially to disable the preview manually to avoid this problem when they will likely do a lot of experimentation and attempts at working on higher poly meshes. Plus, it is going to get old having to disable and enable it every time you want to work with it when switching from high to low poly objects and vice versa. That said, you could have a toggable option to always show the preview by overriding the automatic disable on higher poly meshes, but it should come with a warning about performance as a pop-up box or in the description itself.

Richard Antalik commented

2020-01-20 12:47:27 +01:00

Added subscriber: @iss

Richard Antalik commented

2020-01-20 12:47:27 +01:00

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

Richard Antalik commented

2020-01-20 12:47:27 +01:00

@PabloDobarro will confirm this on your behalf

Philipp Oeser removed the

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Just selecting the IK Pose brush with more than one segment and/or smooth iterations heavily slows down Blender when working with high poly sculpts #73172