Cycles Bake Selected to Active with transparency gives undesirable results #72085

New Issue

Fractures · 2019-12-01T08:56:44+01:00

Fractures commented

2019-12-01 08:56:44 +01:00

System Information:
Operating system: Windows-8.1-6.3.9600 64 Bits
Graphics card: GeForce GT 635M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 391.35
Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-11-20 14:27, hash: 26bd5ebd42

Bug or unintended behavior:
Baking using "Selected to Active" does not take into account transparency

How to reproduce:
Create two objects with materials and textures assigned to each;

  One texture to be baked to
  One texture with an alpha channel (optionally a normal map)

In the shader editor, modify the material of the object with a transparency channel

  Join the transparent textures' alpha into the alpha of the shader that is being used
  (optionally join the color of a normal map)

In render properties, enable Selected to Active and use an appropriate ray distance

  Finally bake.

Result:
When baking combined or most channels, the transparent areas will assume the color as if it were completely opaque,
When baking normals with transparency, the transparent areas will mix with the normal of the geometry that is being baked to the active selection.
Both outcomes are unfavorable when working with transparent cards/ribbons.

bugreport.blend

I packed the textures edited the project to make the issues that I am having more clear.

{F8286028, size=full}
There are now 3 overlapping objects with transparency.
After baking normals or color, none of the colors or normals behind the transparent objects appear because the object appears to draw over top without transparency.
This example also shows that with full normal transparency, the normal will then be the geometry normal of the object rather than a flat normal or anything that is below the object.

System Information: Operating system: Windows-8.1-6.3.9600 64 Bits Graphics card: GeForce GT 635M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 391.35 Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-11-20 14:27, hash: `26bd5ebd42` Bug or unintended behavior: Baking using "Selected to Active" does not take into account transparency How to reproduce: Create two objects with materials and textures assigned to each; ``` One texture to be baked to One texture with an alpha channel (optionally a normal map) ``` In the shader editor, modify the material of the object with a transparency channel ``` Join the transparent textures' alpha into the alpha of the shader that is being used (optionally join the color of a normal map) ``` In render properties, enable Selected to Active and use an appropriate ray distance ``` Finally bake. ``` Result: When baking combined or most channels, the transparent areas will assume the color as if it were completely opaque, When baking normals with transparency, the transparent areas will mix with the normal of the geometry that is being baked to the active selection. Both outcomes are unfavorable when working with transparent cards/ribbons. [bugreport.blend](https://archive.blender.org/developer/F8286027/bugreport.blend) I packed the textures edited the project to make the issues that I am having more clear. {[F8286028](https://archive.blender.org/developer/F8286028/image.png), size=full} There are now 3 overlapping objects with transparency. After baking normals or color, none of the colors or normals behind the transparent objects appear because the object appears to draw over top without transparency. This example also shows that with full normal transparency, the normal will then be the geometry normal of the object rather than a flat normal or anything that is below the object.

Fractures commented

2019-12-01 08:56:44 +01:00

Added subscriber: @Frautcres

Germano Cavalcante commented

2019-12-03 15:49:08 +01:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2019-12-03 15:49:08 +01:00

Is this similar to #50698?

Fractures commented

2019-12-04 00:57:59 +01:00

In #72085#823153, @mano-wii wrote:
Is this similar to #50698?

Issue referenced appears to be about color mixing

The project referenced can be slightly modified and shows the problem still exists pre-2.80

Left is the diffuse bake with overlapping quads drawing completely opaque overtop of each other, right is the render viewport, which is what I would have expected the bake to do.
{F8188468, size=full}

> In #72085#823153, @mano-wii wrote: > Is this similar to #50698? Issue referenced appears to be about color mixing The project referenced can be slightly modified and shows the problem still exists pre-2.80 Left is the diffuse bake with overlapping quads drawing completely opaque overtop of each other, right is the render viewport, which is what I would have expected the bake to do. {[F8188468](https://archive.blender.org/developer/F8188468/image.png), size=full}

Jacques Lucke commented

2020-01-15 13:48:31 +01:00

Added subscriber: @JacquesLucke

Jacques Lucke commented

2020-01-15 13:48:31 +01:00

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

Jacques Lucke commented

2020-01-15 13:48:31 +01:00

@Frautcres Your file is missing texture files. Please pack those into the file and upload it again.

Fractures commented

2020-01-18 21:37:12 +01:00

@JacquesLucke I have packed the textures and modified the project slightly in order to show the issues that I am having more clearly.

Brecht Van Lommel commented

2020-01-19 16:12:04 +01:00

Added subscriber: @brecht

Brecht Van Lommel commented

2020-01-19 16:12:04 +01:00

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

Brecht Van Lommel commented

2020-01-19 16:12:04 +01:00

This use case is just no supported by the implementation at all, it would require major changes to make baking take into account multiple objects for a single pixel.

Philipp Oeser removed the

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Cycles Bake Selected to Active with transparency gives undesirable results #72085