Hair Curves: Create Guide Index Map: Group IDs over 2621 among other thresholds randomly delete a large amount of guide curves #116735

New Issue

SleepyEngi · 2024-01-03T09:32:44+01:00

SleepyEngi commented

2024-01-03 09:32:44 +01:00

System Information
Operating system: Windows 10
Graphics card: Nvidia RTX 2060 Super

Blender Version
Broken: 3.6, 4.0
Worked: n/a

Short description of error
The "Create Guide Index Map" node group for hair curves deletes guide curves at certain thresholds- the first one I found was 2621- over which, it will randomly delete a large number of guide curves- when they should in theory remain the exact same regardless of the number.
There may be other smaller thresholds- depending on the guide distance used. In my case, I was using 0.01, which's first major threshold was 2621.

Exact steps for others to reproduce the error
Based on the default startup or an attached .blend file (as simple as possible).
Change the "Group ID" input from 2621 to 2622 or anything over that. A large amount of curves disappears.

Details
Normally, the group ID is supposed to be used for parting: Curves will only get the guide_curve_index of a guide curve with the same group ID. So changing the group ID should not affect the guide curves themselves no matter what the value is.

But I'm experiencing minor random deletions on any change- from 0 to 1, it's unnoticeable- but from 0 to 100- you can see some shuffle around. The first major threshold is at 2621- right after going to 2622, a majority of the guide curves get deleted. This will happen again at other thresholds over 5000, 8000, etc (Not exact values). There may be smaller thresholds that are unnoticed if the guide curve distance is large enough to hide the fact that guide curves under that distance got deleted

Here, you can see the guide curves when the group ID is 0
Group ID: 0

Here we change it to 2621 - it is nearly identical
Group ID: 2621

But as soon as we change it to 2622, 66% of the guide curves vanish.
Group ID: 2622

**System Information** Operating system: Windows 10 Graphics card: Nvidia RTX 2060 Super **Blender Version** Broken: 3.6, 4.0 Worked: n/a **Short description of error** The "Create Guide Index Map" node group for hair curves deletes guide curves at certain thresholds- the first one I found was 2621- over which, it will randomly delete a large number of guide curves- when they should in theory remain the exact same regardless of the number. There may be other smaller thresholds- depending on the guide distance used. In my case, I was using 0.01, which's first major threshold was 2621. **Exact steps for others to reproduce the error** Based on the default startup or an attached .blend file (as simple as possible). Change the "Group ID" input from 2621 to 2622 or anything over that. A large amount of curves disappears. **Details** Normally, the group ID is supposed to be used for parting: Curves will only get the guide_curve_index of a guide curve with the same group ID. So changing the group ID should not affect the guide curves themselves no matter what the value is. But I'm experiencing minor random deletions on any change- from 0 to 1, it's unnoticeable- but from 0 to 100- you can see some shuffle around. The first major threshold is at 2621- right after going to 2622, a majority of the guide curves get deleted. This will happen again at other thresholds over 5000, 8000, etc (Not exact values). There may be smaller thresholds that are unnoticed if the guide curve distance is large enough to hide the fact that guide curves under that distance got deleted Here, you can see the guide curves when the group ID is 0 [Group ID: 0](https://i.imgur.com/rE6mOYc.png) Here we change it to 2621 - it is nearly identical [Group ID: 2621](https://i.imgur.com/tSF8SyO.png) But as soon as we change it to 2622, 66% of the guide curves vanish. [Group ID: 2622](https://i.imgur.com/SIK3Idu.png)

report.blend

4.4 MiB

report2.PNG

666 KiB

report0.PNG

660 KiB

report1.PNG

674 KiB

SleepyEngi added the

labels 2024-01-03 09:32:45 +01:00

Richard Antalik commented

2024-01-04 22:11:51 +01:00

I have looked at the node tree for quite long time, Still not quite sure how this works. Seems that Group ID somehow influences curve_guide_index value and this is then rejected when compared with index node.

In any case if I understand this correctly, it is broken so will confirm

I have looked at the node tree for quite long time, Still not quite sure how this works. Seems that Group ID somehow influences `curve_guide_index` value and this is then rejected when compared with index node. In any case if I understand this correctly, it is broken so will confirm

Richard Antalik added

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Hair Curves: Create Guide Index Map: Group IDs over 2621 among other thresholds randomly delete a large amount of guide curves #116735