Artifacts during baking. Multicolored dots and dashes. #42580

New Issue

Viktor · 2014-11-12T15:15:31+01:00

Viktor commented

2014-11-12 15:15:31 +01:00

System Information
Operating system and graphics card
Windows 7
NVIDIA GeForce GTX 670

Blender Version
Broken: (example: 2.69.7 4b206af, see splash screen)
Worked: (optional)
Blender 7.2

Short description of error

When baking normal map artifacts appear in the form of dots and dashes but when I turn normal objects (low poly Hight and Cage) then the problem disappears. In this file, just put the render Cycles and click bake. And when the normal inward then all is well.
Stolik_work.zip

**System Information** Operating system and graphics card Windows 7 NVIDIA GeForce GTX 670 **Blender Version** Broken: (example: 2.69.7 4b206af, see splash screen) Worked: (optional) Blender 7.2 **Short description of error** When baking normal map artifacts appear in the form of dots and dashes but when I turn normal objects (low poly Hight and Cage) then the problem disappears. In this file, just put the render Cycles and click bake. And when the normal inward then all is well. [Stolik_work.zip](https://archive.blender.org/developer/F123468/Stolik_work.zip) ![Bug.JPG](https://archive.blender.org/developer/F123469/Bug.JPG)

Viktor commented

2014-11-12 15:15:31 +01:00

Changed status to: 'Open'

Viktor commented

2014-11-12 15:15:31 +01:00

Added subscriber: @Vik_zxl

Dalai Felinto was assigned by Julian Eisel

2014-11-12 16:04:16 +01:00

Julian Eisel commented

2014-11-12 16:04:16 +01:00

Added subscriber: @JulianEisel

Viktor commented

2014-11-12 16:41:47 +01:00

Sorry! Version 2.72

Dalai Felinto commented

2014-11-12 16:57:43 +01:00

Added subscriber: @AndyDavies-3

Dalai Felinto commented

2014-11-12 16:57:43 +01:00

I'm not sure I fully understand what you're reporting. Cage (or even the extrusion option) is exactly to handle special cases/artifacts. @AndyDavies-3 any thoughts here?

Viktor commented

2014-11-12 17:15:20 +01:00

I have attached the file. In the file you just have to press and bake in the UV will be the normal map. On the normal map visible noise. I used to render Cycles. When I change the direction of the normals of objects Hight poly and Low poly and bake it the problem disappears and the noise does not appear.

Andy Davies commented

2014-11-12 17:57:14 +01:00

Hey guys,

I don't have much time atm, but I will make sure to have a look later tonight.

Cheers

Hey guys, I don't have much time atm, but I will make sure to have a look later tonight. Cheers

Sergey Sharybin commented

2014-12-26 10:26:12 +01:00

Added subscriber: @Sergey

Sergey Sharybin commented

2014-12-26 10:26:12 +01:00

What's the status here?

Andy Davies commented

2014-12-26 18:41:17 +01:00

Sorry for the late reply! I have been checking this periodicity and havent had time to post.

As it stands I cannot see for sure why this is happening.

I cant see anything wrong with the set up in regards to the meshes having extra faces, verts or the cage etc. so in theory it should bake well enough and in fact bakes perfectly in xNormal (map attached). The high poly mesh does have a few ngons, but that shouldn't make much difference really.

When the high poly mesh is set to flat shaded the problem is resolved.

Blender must be doing something internally that is causing the baker to write incorrect values to the edges, but I have no idea what that could be at the moment.

I cant seem to upload files so I have linked from dropbox
https://dl.dropboxusercontent.com/u/2057427/Bug%20Reports/Blender/render_error_normals.png

Sorry for the late reply! I have been checking this periodicity and havent had time to post. As it stands I cannot see for sure why this is happening. I cant see anything wrong with the set up in regards to the meshes having extra faces, verts or the cage etc. so in theory it should bake well enough and in fact bakes perfectly in xNormal (map attached). The high poly mesh does have a few ngons, but that shouldn't make much difference really. When the high poly mesh is set to flat shaded the problem is resolved. Blender must be doing something internally that is causing the baker to write incorrect values to the edges, but I have no idea what that could be at the moment. I cant seem to upload files so I have linked from dropbox https://dl.dropboxusercontent.com/u/2057427/Bug%20Reports/Blender/render_error_normals.png

Julian Eisel commented

2014-12-26 19:12:33 +01:00

chances are this got fixed with cf178f71ac, so might be worth testing again

chances are this got fixed with cf178f71ac, so might be worth testing again

Andy Davies commented

2014-12-29 23:45:03 +01:00

I have no idea how the new hash system from Github works but I just tested with r5ea243b and the issue is still there.

Not sure if this a later build than the one you mentioned @JulianEisel

I have no idea how the new hash system from Github works but I just tested with r5ea243b and the issue is still there. Not sure if this a later build than the one you mentioned @JulianEisel

Julian Eisel commented

2014-12-29 23:55:13 +01:00

Just try a build from buildbot

Just try a build from [buildbot ](https://builder.blender.org/download/)

Andy Davies commented

2014-12-30 00:22:11 +01:00

In #42580#277869, @JulianEisel wrote:
Just try a build from buildbot

That was a build from Buildbot ;)

The problem I have is that the r version you mentioned and the one on the splash screen bear no resemblance to each other.

> In #42580#277869, @JulianEisel wrote: > Just try a build from [buildbot ](https://builder.blender.org/download/) That was a build from Buildbot ;) The problem I have is that the r version you mentioned and the one on the splash screen bear no resemblance to each other.

Julian Eisel commented

2014-12-30 00:46:33 +01:00

That's no problem, the build from buildbot includes the fix I mentioned.

Dalai Felinto commented

2015-01-05 19:27:39 +01:00

Happy new year. I was away for the holidays as well and can now help looking at this too. @AndyDavies-3 the image you posted seems artifact-free. Am I missing something?

Edit/Update: your image is baked from xNormals, right? Let me investigate this then.

Happy new year. I was away for the holidays as well and can now help looking at this too. @AndyDavies-3 the image you posted seems artifact-free. Am I missing something? Edit/Update: your image is baked from xNormals, right? Let me investigate this then.

Dalai Felinto commented

2015-01-05 20:27:34 +01:00

Attached is a simplified version of the original file (the mesh is still the same, I just purged the file from all unneeded objects): Stolik_work_2.blend

@Vik_zxl can you rephrase your original statement on how to 'fix'/workaround the bug? In other words, how to take the attached file and make it bake correctly.

The highpoly object is very dense, that may be the reason of the issue. Or the cage, though the cage seems fine.

Attached is a simplified version of the original file (the mesh is still the same, I just purged the file from all unneeded objects): [Stolik_work_2.blend](https://archive.blender.org/developer/F135472/Stolik_work_2.blend) @Vik_zxl can you rephrase your original statement on how to 'fix'/workaround the bug? In other words, how to take the attached file and make it bake correctly. The highpoly object is very dense, that may be the reason of the issue. Or the cage, though the cage seems fine.

ronan ducluzeau commented

2015-01-05 21:39:47 +01:00

Added subscriber: @zeauro

ronan ducluzeau commented

2015-01-05 21:39:47 +01:00

It is difficult for any renderer to give correct representation of stretched faces.

Here, we are trying to represent several long stretched faces in a column of a larger of one pixel in baked image.

If faces of high poly mesh are cut to be less longer, it is easier for the renderer to do an average approximation of the result from more info.

Stolik_work_2_cutfix.blend

It is difficult for any renderer to give correct representation of stretched faces. Here, we are trying to represent several long stretched faces in a column of a larger of one pixel in baked image. If faces of high poly mesh are cut to be less longer, it is easier for the renderer to do an average approximation of the result from more info. [Stolik_work_2_cutfix.blend](https://archive.blender.org/developer/F135507/Stolik_work_2_cutfix.blend)

Dalai Felinto commented

2015-01-05 21:48:31 +01:00

Blender internal bakes fine the original file (or rather: Stolik_work_2.blend), so (1) it may be something fixable; (2) you may not need the cage in this case (at least not for the bug report).

@Sergey what do you say? Is it a bug, or simply a "limitation"? Any clues on what may be causing this?

Blender internal bakes fine the original file (or rather: Stolik_work_2.blend), so (1) it may be something fixable; (2) you may not need the cage in this case (at least not for the bug report). @Sergey what do you say? Is it a bug, or simply a "limitation"? Any clues on what may be causing this?

Dalai Felinto commented

2015-01-06 02:30:17 +01:00

A simplified version of the latest file, with the minimal part required to show the bug. As @zeauro pointed out, if you create edge loops in the highpoly mesh the issue disappears: Stolik_work_3.blend

A simplified version of the latest file, with the minimal part required to show the bug. As @zeauro pointed out, if you create edge loops in the highpoly mesh the issue disappears: [Stolik_work_3.blend](https://archive.blender.org/developer/F135530/Stolik_work_3.blend)

Viktor commented

2015-01-06 14:51:47 +01:00

I downloaded your latest file. pressed to bake and this is what I was given. the problem remains. Of course if you put a bunch of flat and put it subdivisions blender can bake normal and subdivisoins give smoothing. But this is not the solution

![buggggzzz.png](https://archive.blender.org/developer/F135610/buggggzzz.png) I downloaded your latest file. pressed to bake and this is what I was given. the problem remains. Of course if you put a bunch of flat and put it subdivisions blender can bake normal and subdivisoins give smoothing. But this is not the solution

Julian Eisel commented

2015-02-19 16:47:27 +01:00

Added subscriber: @dfelinto

Julian Eisel commented

2015-02-19 16:47:27 +01:00

@dfelinto, @Sergey, what's up with this? For me it really looks like a cornercase (even literally ;) ) we can't handle correctly.

Julian Eisel commented

2015-03-08 21:22:20 +01:00

@dfelinto, @Sergey, asking again... bug or hardly fixable cornercase?

Sergey Sharybin commented

2015-03-09 11:40:38 +01:00

The issue is caused by lack of accuracy in BLI_bvhtree, which misses some intersections (empty pixels in output) and causes artifacts (mainly when it records wrong intersection).

We'll be doing various improvements to BLI_bvh as a part of boolean operations support in bmesh rather soon, would be a nice reference for the new implementation check.

For until then i wouldn't consider it's a bug, just a limitation of current BVH.

The issue is caused by lack of accuracy in BLI_bvhtree, which misses some intersections (empty pixels in output) and causes artifacts (mainly when it records wrong intersection). We'll be doing various improvements to BLI_bvh as a part of boolean operations support in bmesh rather soon, would be a nice reference for the new implementation check. For until then i wouldn't consider it's a bug, just a limitation of current BVH.

Dalai Felinto was unassigned by Sergey Sharybin

2015-03-09 11:40:52 +01:00

Sergey Sharybin self-assigned this 2015-03-09 11:40:52 +01:00

Stefano Bonicatti commented

2020-05-31 22:02:39 +02:00

Added subscriber: @Smjert

Stefano Bonicatti commented

2020-05-31 22:02:39 +02:00

Tested this with Blender 2.90 (2ee94c954d) and I don't see this issue in Stolik_work_3.blend.

Tested this with Blender 2.90 (2ee94c954d6700a45fde320f330964bcf1888545) and I don't see this issue in `Stolik_work_3.blend`.

Sergey Sharybin commented

2021-10-06 12:05:20 +02:00

Changed status from 'Confirmed' to: 'Resolved'

Sergey Sharybin closed this issue

2021-10-06 12:05:20 +02:00

Sergey Sharybin commented

2021-10-06 12:05:20 +02:00

The issue is old and does not happen anymore. Also, not really something I am currently actively looking into.

If the issue still happens please submit a new report!

The issue is old and does not happen anymore. Also, not really something I am currently actively looking into. If the issue still happens please submit a new report!

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Artifacts during baking. Multicolored dots and dashes. #42580