Regression: Subdivide Curve node functions incorrectly when operating on certain outputs of a Mesh to Curve node #99648

New Issue

AgentA1cr · 2022-07-12T16:51:59+02:00

AgentA1cr commented

2022-07-12 16:51:59 +02:00

System Information
Operating system: Windows-10-10.0.19044-SP0 64 Bits
Graphics card: Quadro K3100M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 426.78

Blender Version
Broken: version: 3.3.0 Alpha, branch: master, commit date: 2022-07-11 17:16, hash: 2a1d12d7a0
Worked: 3.2.1
Caused by 9435ee8c65

Short description of error
When using the Mesh to Curve node on a mesh with vertices that have more than two connected edges, the resulting geometry is not properly handled by the Subdivide Curve node. Some curve control points located at such vertices have their positions reset to the origin. The bug did not occur when I tested it with a curve whose control points shared the same position for other reasons.

I suspect this is likely related to #95443

Exact steps for others to reproduce the error
See attached .blend file:
Mesh To Curve Subdivide Bug.blend

**System Information** Operating system: Windows-10-10.0.19044-SP0 64 Bits Graphics card: Quadro K3100M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 426.78 **Blender Version** Broken: version: 3.3.0 Alpha, branch: master, commit date: 2022-07-11 17:16, hash: `2a1d12d7a0` Worked: 3.2.1 Caused by 9435ee8c65 **Short description of error** When using the Mesh to Curve node on a mesh with vertices that have more than two connected edges, the resulting geometry is not properly handled by the Subdivide Curve node. Some curve control points located at such vertices have their positions reset to the origin. The bug did not occur when I tested it with a curve whose control points shared the same position for other reasons. ![image.png](https://archive.blender.org/developer/F13288837/image.png) I suspect this is likely related to #95443 **Exact steps for others to reproduce the error** See attached .blend file: [Mesh To Curve Subdivide Bug.blend](https://archive.blender.org/developer/F13288909/Mesh_To_Curve_Subdivide_Bug.blend)

AgentA1cr commented

2022-07-12 16:51:59 +02:00

Added subscriber: @AgentA1cr

D0ppelgaenger commented

2022-07-12 17:57:51 +02:00

Added subscriber: @Leo-Luther

D0ppelgaenger commented

2022-07-12 17:57:51 +02:00

I can confirm this behavior, yet it is not due to how many edges were connected to a point or points sharing positions, or due to the mesh to curves at all.

The issue comes up if your curve object (whether created via mesh to curve or not) has more than 1 spline.
The index of the endpoints seems to get messed up and they "loose" their position (get set to (0|0|0))

I can confirm this behavior, yet it is not due to how many edges were connected to a point or points sharing positions, or due to the mesh to curves at all. The issue comes up if your curve object (whether created via mesh to curve or not) has more than 1 spline. The index of the endpoints seems to get messed up and they "loose" their position (get set to (0|0|0)) ![image.png](https://archive.blender.org/developer/F13288978/image.png) ![image.png](https://archive.blender.org/developer/F13288998/image.png)

Pratik Borhade commented

2022-07-13 13:18:51 +02:00

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

Pratik Borhade changed title from ~~Subdivide Curve node functions incorrectly when operating on certain outputs of a Mesh to Curve node~~ to Regression: Subdivide Curve node functions incorrectly when operating on certain outputs of a Mesh to Curve node

2022-07-13 13:19:08 +02:00

Pratik Borhade commented

2022-07-13 13:35:21 +02:00

Added subscribers: @HooglyBoogly, @PratikPB2123

Pratik Borhade commented

2022-07-13 13:35:21 +02:00

I suspect this is likely related to #95443

yes, caused by {9435ee8c65193e3d4af8f1ac5b07b7884cf62bd5}
cc @HooglyBoogly

> I suspect this is likely related to #95443 yes, caused by {9435ee8c65193e3d4af8f1ac5b07b7884cf62bd5} cc @HooglyBoogly

D0ppelgaenger commented

2022-07-13 21:49:51 +02:00

I want to reiterate that it does not seem to be due to the mesh to curve, but it is a general issue with the subdivide curves node on all poly splines (more than one spline).

If you mesh to curve and then change the spline type to anything other than "poly" before subdividing, it will work fine.
The subdivision will also not work correctly using multiple "regularly" created poly splines (mesh line e.g.)

I want to reiterate that it does not seem to be due to the mesh to curve, but it is a general issue with the subdivide curves node **on all poly splines** (more than one spline). If you mesh to curve and then change the spline type to anything other than "poly" before subdividing, it will work fine. The subdivision will also not work correctly using multiple "regularly" created poly splines (mesh line e.g.)

Hans Goudey was assigned by Dalai Felinto

2022-07-15 16:34:23 +02:00

D0ppelgaenger commented

2022-07-19 23:40:52 +02:00

Seems to also be happening on more than one NURBS curves

Seems to also be happening on more than one NURBS curves ![image.png](https://archive.blender.org/developer/F13301495/image.png) ![image.png](https://archive.blender.org/developer/F13301492/image.png)

Iliya Katushenock commented

2022-07-20 00:12:07 +02:00

Added subscriber: @mod_moder

Iliya Katushenock commented

2022-07-20 00:12:07 +02:00

I tried to research this question. So far, I've only noticed that point offsets are written using an always empty mask. But fixing that didn't fix things much. Although, if there are other problems, then the 0th offset still united

Hans Goudey commented

2022-07-25 22:23:45 +02:00

Changed status from 'Confirmed' to: 'Resolved'

Hans Goudey closed this issue

2022-07-25 22:23:45 +02:00

Hans Goudey commented

2022-07-25 22:23:45 +02:00

I'm fairly certain this is resolved with recent fixes to the subdivide node. If it's not, we can reopen this task. Thanks for the report.

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Regression: Subdivide Curve node functions incorrectly when operating on certain outputs of a Mesh to Curve node #99648