cycles can not start sampling while a new curve object with the default radius in the scene #97584

New Issue

yonghao lv · 2022-04-24T03:56:03+02:00

yonghao lv commented

2022-04-24 03:56:03 +02:00

System Information
Operating system: Windows-10-10.0.22000-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 2080 SUPER/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 512.15

Blender Version
Broken: version: 3.2.0 Alpha, branch: master, commit date: 2022-04-23 13:09, hash: c486da0238

Short description of error
cycles can not start sampling while a new curve object with the default radius in the scene

Exact steps for others to reproduce the error

import this abc file
Enable New curve type from experimental tab
{nav Shift + A > Curves > Select Any}
Create node tree as shown in video on this curve object
Switch render to cycles
Change radius value
cat.abc
2022-04-24 09-50-34.mp4

**System Information** Operating system: Windows-10-10.0.22000-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 2080 SUPER/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 512.15 **Blender Version** Broken: version: 3.2.0 Alpha, branch: master, commit date: 2022-04-23 13:09, hash: `c486da0238` **Short description of error** cycles can not start sampling while a new curve object with the default radius in the scene **Exact steps for others to reproduce the error** - import this abc file - Enable New curve type from experimental tab - {nav Shift + A > Curves > Select Any} - Create node tree as shown in video on this curve object - Switch render to cycles - Change radius value [cat.abc](https://archive.blender.org/developer/F13020472/cat.abc) [2022-04-24 09-50-34.mp4](https://archive.blender.org/developer/F13020460/2022-04-24_09-50-34.mp4)

yonghao lv commented

2022-04-24 03:56:03 +02:00

Added subscriber: @1029910278

Pratik Borhade commented

2022-04-25 06:57:28 +02:00

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

Pratik Borhade commented

2022-04-25 06:57:31 +02:00

Added subscriber: @PratikPB2123

Brecht Van Lommel commented

2022-04-28 20:03:55 +02:00

Added subscribers: @HooglyBoogly, @brecht

Brecht Van Lommel commented

2022-04-28 20:03:55 +02:00

@HooglyBoogly can we lower the default radius value in this node? I think a default radius of 1 meter is not that useful, and it might make sense to set it to something that is a good default for hair.

In general, rendering many overlapping curves like this is going to lead to poor performance, and there is not a lot we can do about it. Especially for ray-tracing bounds are not going to be very tight and every ray may intersect hundreds of thousands of hairs.

@HooglyBoogly can we lower the default radius value in this node? I think a default radius of 1 meter is not that useful, and it might make sense to set it to something that is a good default for hair. In general, rendering many overlapping curves like this is going to lead to poor performance, and there is not a lot we can do about it. Especially for ray-tracing bounds are not going to be very tight and every ray may intersect hundreds of thousands of hairs.

Hans Goudey commented

2022-04-28 20:16:31 +02:00

There's a bit of a conflict here between the uses for curves here I think (lamp-posts, tentacles, trees, cables, tubes, hair, carpets).

I'm a little skeptical of a "good default for hair", since I'd expect that's something like 1mm or less. That's practically invisible if you're not zoomed in very closely.

Do you think 0.1m is reasonable? That would be visible when more zoomed out but less absurd for hair uses cases.

There's a bit of a conflict here between the uses for curves here I think (lamp-posts, tentacles, trees, cables, tubes, hair, carpets). I'm a little skeptical of a "good default for hair", since I'd expect that's something like 1mm or less. That's practically invisible if you're not zoomed in very closely. Do you think 0.1m is reasonable? That would be visible when more zoomed out but less absurd for hair uses cases.

Juan Gea commented

2022-04-28 23:22:16 +02:00

Added subscriber: @juang3d

Juan Gea commented

2022-04-28 23:22:16 +02:00

If I may, .01m seems more reasonable, 1cm, and can prevent problems in many situations, more than 10cm I think.

Just my 2 cents :)

If I may, .01m seems more reasonable, 1cm, and can prevent problems in many situations, more than 10cm I think. Just my 2 cents :)

Brecht Van Lommel commented

2022-04-29 19:31:08 +02:00

With 10cm thick hair it's still going to be pretty bad when accidentally using that, nearly all of it will overlap still.

Something like 1cm or a bit less like 0.5cm would be a lot better, matching a typical cable or twig.

With 10cm thick hair it's still going to be pretty bad when accidentally using that, nearly all of it will overlap still. Something like 1cm or a bit less like 0.5cm would be a lot better, matching a typical cable or twig.

yonghao lv commented

2022-05-01 21:22:08 +02:00

I notice that not all situation is suitable for small default value. Some company use 'mm' to produce their 3d print wax model (for example, jewel), so 1mm in these scenes is fine.
Maybe just set a color tips on the render view(also on the set radius node) , and exclude the curve object from rendering.

I notice that not all situation is suitable for small default value. Some company use 'mm' to produce their 3d print wax model (for example, jewel), so 1mm in these scenes is fine. Maybe just set a color tips on the render view(also on the set radius node) , and exclude the curve object from rendering.

blender-admin commented

2022-07-08 15:53:57 +02:00

This issue was referenced by 8159e0a666

This issue was referenced by 8159e0a666d3d51936e50a36912f38386570af11

Brecht Van Lommel commented

2022-07-08 16:42:35 +02:00

Changed status from 'Confirmed' to: 'Resolved'

Brecht Van Lommel closed this issue

2022-07-08 16:42:35 +02:00

Brecht Van Lommel self-assigned this 2022-07-08 16:42:35 +02:00

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cycles can not start sampling while a new curve object with the default radius in the scene #97584