Sculpting with dyntopo "brush detail" crashes Blender. #45043

New Issue

Eli Innis · 2015-06-12T06:01:48+02:00

Eli Innis commented

2015-06-12 06:01:48 +02:00

System Information
SolydX-64 on Dell Laptop - Latitude D530 onboard video
Intel ® Graphics Media Accelerator X3100

Blender Version
Broken: 2.75 rc1
Worked: well, there's no "brush detail" for dyntopo before this,
but the other dyntopo modes seem to work ok.

Short description of error
Sculpting with dyntopo "brush detail" seems to crash Blender.

Exact steps for others to reproduce the error
Load factory defaults.

Join the main area down
'cuz you don't need animation area down there.

Delete the cube. Create icosphere.

Sculpt mode. Symmetry on or off.

Enable tablet pressure for size.
I have a Wacom Bamboo tablet.

Dyntopo, Brush detail.

Sculpt for a minute or two.

It seems that once the verts get to about
30,000-45,000 or the tris get to about 60,000-90,000
then the processor runs up and Blender hangs.

To exit, I have to bring up the task manager, and kill the process.

**System Information** SolydX-64 on Dell Laptop - Latitude [D530](https://archive.blender.org/developer/D530) onboard video Intel ® Graphics Media Accelerator X3100 **Blender Version** Broken: 2.75 rc1 Worked: well, there's no "brush detail" for dyntopo before this, but the other dyntopo modes seem to work ok. **Short description of error** Sculpting with dyntopo "brush detail" seems to crash Blender. **Exact steps for others to reproduce the error** Load factory defaults. Join the main area down 'cuz you don't need animation area down there. Delete the cube. Create icosphere. Sculpt mode. Symmetry on or off. Enable tablet pressure for size. I have a Wacom Bamboo tablet. Dyntopo, Brush detail. Sculpt for a minute or two. It seems that once the verts get to about 30,000-45,000 or the tris get to about 60,000-90,000 then the processor runs up and Blender hangs. To exit, I have to bring up the task manager, and kill the process.

Eli Innis commented

2015-06-12 06:01:48 +02:00

Changed status to: 'Open'

Eli Innis commented

2015-06-12 06:01:48 +02:00

Added subscriber: @Doyousketch2

Bastien Montagne commented

2015-06-12 10:11:49 +02:00

Added subscribers: @Psy-Fi, @mont29

Bastien Montagne commented

2015-06-12 10:11:49 +02:00

This sounds like simple hang on big polycount mesh… Your 'GPU' is veryvery low, and for sure won't be able to handle heavy geometry.

You say other brush modes work OK, but did you reach that number of triangles with them?

@Psy-Fi may have better insight here, too.

This sounds like simple hang on big polycount mesh… Your 'GPU' is veryvery low, and for sure won't be able to handle heavy geometry. You say other brush modes work OK, but did you reach that number of triangles with them? @Psy-Fi may have better insight here, too.

Antonis Ryakiotakis commented

2015-06-12 11:35:09 +02:00

It may indeed be due to a faulty GPU driver. Brush detail makes things worse because it can make polycounts explode with small brush sizes leading to driver having an issue catching up (generating too many vertex buffer objects or so). I think it would be nice to clamp the brush detail to the constant detail actually to avoid situations such as these.

Eli Innis commented

2015-06-12 17:01:43 +02:00

It seems that when I use the other dyntopo modes I can easily go over 200k tris with no issues,
450,000 before it slows down. I kept going all the way up to 1.25 mil just to be sure.

The memory use doesn't peak, so that doesn't seem to be an issue.

The funny thing is, when the processor runs up, it seems to hang between 40 and 50%
which I'd think means it's only using up one of the cores on its Core2Duo.

It'll do a similar thing while in the other modes, where it'll pause for a second or so,
as if to recalculate the mesh or something, sorta like when a swap file is being written to.

The thing is, in the other modes it always returns control, so you can get back to sculpting.
Brush detail mode doesn't relinquish control, even if I wait for a few minutes.

It seems that when I use the other dyntopo modes I can easily go over 200k tris with no issues, 450,000 before it slows down. I kept going all the way up to 1.25 mil just to be sure. The memory use doesn't peak, so that doesn't seem to be an issue. The funny thing is, when the processor runs up, it seems to hang between 40 and 50% which I'd think means it's only using up one of the cores on its Core2Duo. It'll do a similar thing while in the other modes, where it'll pause for a second or so, as if to recalculate the mesh or something, sorta like when a swap file is being written to. The thing is, in the other modes it always returns control, so you can get back to sculpting. Brush detail mode doesn't relinquish control, even if I wait for a few minutes.

Eli Innis commented

2015-06-12 23:47:18 +02:00

I do appreciate the feedback. I listened to what you said,
and did a full system update, to make sure drivers were as good as could be.

It seems to be doing better, so maybe it was as you say.

I notice that if I just do Subdivide edges,
or just do Collapse edges,
then I get a faster response time.

When combined as Subdivide Collapse mode,
that's when it had those little lag moments.
You get smooth sculpts that way tho, so I like 'em both on.

I guess my recommendation for the Brush detail would be that if it's already known
that setting this slider too low brings the poly count up high real quick,
and it's also known that too high of a poly count can crash Blender,
then it might do well to set the default to something a bit safer, say 35%

Maybe a warning if you drag it down to less than 15%
I'll play around with it some more and let you know if it misbehaves.

Thanks tremendously for your efforts with Blender.

I do appreciate the feedback. I listened to what you said, and did a full system update, to make sure drivers were as good as could be. It seems to be doing better, so maybe it was as you say. I notice that if I just do Subdivide edges, or just do Collapse edges, then I get a faster response time. When combined as Subdivide Collapse mode, that's when it had those little lag moments. You get smooth sculpts that way tho, so I like 'em both on. I guess my recommendation for the Brush detail would be that if it's already known that setting this slider too low brings the poly count up high real quick, and it's also known that too high of a poly count can crash Blender, then it might do well to set the default to something a bit safer, say 35% Maybe a warning if you drag it down to less than 15% I'll play around with it some more and let you know if it misbehaves. Thanks tremendously for your efforts with Blender.

Antonis Ryakiotakis was assigned by Bastien Montagne

2015-06-19 09:49:21 +02:00

Aaron Carlisle commented

2015-10-06 19:07:46 +02:00

Added subscriber: @Blendify

Aaron Carlisle commented

2015-10-06 19:07:46 +02:00

any reason to have this open if it is a old hardware issue?

Antonis Ryakiotakis removed their assignment 2016-01-06 20:36:52 +01:00

Sergey Sharybin commented

2016-02-02 16:15:11 +01:00

Added subscriber: @Sergey

Sergey Sharybin commented

2016-02-02 16:15:11 +01:00

Changed status from 'Open' to: 'Archived'

Sergey Sharybin closed this issue

2016-02-02 16:15:11 +01:00

Sergey Sharybin self-assigned this 2016-02-02 16:15:11 +01:00

Sergey Sharybin commented

2016-02-02 16:15:11 +01:00

@Doyousketch2, it's not just about number of triangles, but also number of GPU buffers which isn't really linearly depending on the number of triangles.

Surely it's possible to support older hardware, but that's not really effective time investment. So thanks for the report, but closing it now.

@Doyousketch2, it's not just about number of triangles, but also number of GPU buffers which isn't really linearly depending on the number of triangles. Surely it's possible to support older hardware, but that's not really effective time investment. So thanks for the report, but closing it now.

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Sculpting with dyntopo "brush detail" crashes Blender. #45043