Dark Poly spot bug in External renderer #80835

New Issue

Nandeya charles · 2020-09-16T13:50:04+02:00

Nandeya charles commented

2020-09-16 13:50:04 +02:00

System Information
Operating system: Windows 10
Graphics card: RTX 2060S

Blender Version
blender 2.83 LTS and 2.9 official

Short description of error
Random black poly spot appear on object no matter if the normal are correctly set.
This happen to external renderer not CYCLES. Trying with luxcorerender here is the DEvs

Explanation :


ply
format ascii 1.0
comment Created by Blender 2.83.5 - www.blender.org, source file: 'Darkspot bug.blend'
element vertex 96
property float x
property float y
property float z
property float nx
property float ny
property float nz
property float s
property float t
element face 24
property list uchar uint vertex_indices
end_header
-0.291856 -0.093864 0.682044 -0.032319 -0.999451 0.000000 nan nan
-0.300529 -0.093583 0.498582 -0.032319 -0.999451 0.000000 nan nan
-0.264689 -0.094742 0.507916 -0.032319 -0.999451 0.000000 nan nan
-0.263646 -0.094776 0.759046 -0.032319 -0.999451 0.000000 nan nan
-0.300529 -0.093583 0.498582 -0.032319 -0.999451 0.000000 nan nan
-0.301779 -0.093543 0.299369 -0.032319 -0.999451 0.000000 nan nan
-0.264892 -0.094736 0.299369 -0.032319 -0.999451 0.000000 nan nan
-0.264689 -0.094742 0.507916 -0.032319 -0.999451 0.000000 nan nan
[...]

This is a .ply file directly exported from Blender without the use of any LuxCore related code. It is a Blender bug as far as I can see.
The triangles have NaN UV coordinates:
You can report the problem to Blender developers by providing this file a telling them to export in .ply format and check the UV coordinates (aka ST coordinates).
However they may be not able to track the problem from there because the NaN may be the result of the process used to build the mesh (so they may be unable to track what tool is broken and has generated the NaN).

Exact steps for others to reproduce the error
This blend file contain a mesh with the error. You need to have Luxcorerender installed : Luxcore download

Darkspot bug.blend

**System Information** Operating system: Windows 10 Graphics card: RTX 2060S **Blender Version** blender 2.83 LTS and 2.9 official **Short description of error** Random black poly spot appear on object no matter if the normal are correctly set. This happen to external renderer not CYCLES. Trying with luxcorerender here is the DEvs ![darkspot.jpg](https://archive.blender.org/developer/F8888926/darkspot.jpg) Explanation : ``` ply format ascii 1.0 comment Created by Blender 2.83.5 - www.blender.org, source file: 'Darkspot bug.blend' element vertex 96 property float x property float y property float z property float nx property float ny property float nz property float s property float t element face 24 property list uchar uint vertex_indices end_header -0.291856 -0.093864 0.682044 -0.032319 -0.999451 0.000000 nan nan -0.300529 -0.093583 0.498582 -0.032319 -0.999451 0.000000 nan nan -0.264689 -0.094742 0.507916 -0.032319 -0.999451 0.000000 nan nan -0.263646 -0.094776 0.759046 -0.032319 -0.999451 0.000000 nan nan -0.300529 -0.093583 0.498582 -0.032319 -0.999451 0.000000 nan nan -0.301779 -0.093543 0.299369 -0.032319 -0.999451 0.000000 nan nan -0.264892 -0.094736 0.299369 -0.032319 -0.999451 0.000000 nan nan -0.264689 -0.094742 0.507916 -0.032319 -0.999451 0.000000 nan nan [...] ``` This is a .ply file directly exported from Blender without the use of any LuxCore related code. It is a Blender bug as far as I can see. The triangles have NaN UV coordinates: You can report the problem to Blender developers by providing this file a telling them to export in .ply format and check the UV coordinates (aka ST coordinates). However they may be not able to track the problem from there because the NaN may be the result of the process used to build the mesh (so they may be unable to track what tool is broken and has generated the NaN). **Exact steps for others to reproduce the error** This blend file contain a mesh with the error. You need to have Luxcorerender installed : [Luxcore download ](https://luxcorerender.org/download/) [Darkspot bug.blend](https://archive.blender.org/developer/F8888920/Darkspot_bug.blend)

Nandeya charles commented

2020-09-16 13:50:04 +02:00

Added subscriber: @sharlybg

Robert Guetzkow commented

2020-09-16 14:01:53 +02:00

Added subscriber: @rjg

Robert Guetzkow commented

2020-09-16 14:01:53 +02:00

While I haven't tested this yet, this underlying cause for the error might be related to #79775.

Brecht Van Lommel commented

2020-09-16 14:11:06 +02:00

Added subscriber: @brecht

Brecht Van Lommel commented

2020-09-16 14:11:06 +02:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Brecht Van Lommel commented

2020-09-16 14:11:06 +02:00

However they may be not able to track the problem from there because the NaN may be the result of the process used to build the mesh (so they may be unable to track what tool is broken and has generated the NaN).

This is correct. This bug report requires steps to get a mesh into a state where UVs are NaN, otherwise we can't investigate it.

> However they may be not able to track the problem from there because the NaN may be the result of the process used to build the mesh (so they may be unable to track what tool is broken and has generated the NaN). This is correct. This bug report requires steps to get a mesh into a state where UVs are NaN, otherwise we can't investigate it.

Nandeya charles commented

2020-09-16 14:46:37 +02:00

This comment was removed by @sharlybg

*This comment was removed by @sharlybg*

Bastien Montagne commented

2020-09-21 16:48:59 +02:00

Closed as duplicate of #79775

Bastien Montagne closed this issue

2020-09-21 16:48:59 +02:00

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Dark Poly spot bug in External renderer #80835