Shadow pass error: Black shadow #47025

New Issue

Alexey · 2015-12-20T21:57:00+01:00

Alexey commented

2015-12-20 21:57:00 +01:00

System Information
Operating system and graphics card

Blender Version
Broken: (all)
Worked: (none)

Short description of error

Exact steps for others to reproduce the error
black_shadow_bug.blend
open, render - we will see unneed texture in shadow pass
switch off this texture(or correct it's value level) - proper result
set to any material diffuse color with value more than zero - proper result
set to any material diffuse color with value equal zero - bug
P.S. i don't know what about Cycles render - i don't learn cycles

**System Information** Operating system and graphics card **Blender Version** Broken: (all) Worked: (none) **Short description of error** ![1.png](https://archive.blender.org/developer/F269855/1.png) ![2.png](https://archive.blender.org/developer/F269857/2.png) ![3.png](https://archive.blender.org/developer/F269859/3.png) ![4.png](https://archive.blender.org/developer/F269861/4.png) ![5.png](https://archive.blender.org/developer/F269863/5.png) **Exact steps for others to reproduce the error** [black_shadow_bug.blend](https://archive.blender.org/developer/F269865/black_shadow_bug.blend) open, render - we will see unneed texture in shadow pass switch off this texture(or correct it's value level) - proper result set to any material diffuse color with value more than zero - proper result set to any material diffuse color with value equal zero - bug P.S. i don't know what about Cycles render - i don't learn cycles

Alexey commented

2015-12-20 21:57:00 +01:00

Changed status to: 'Open'

Alexey commented

2015-12-20 21:57:00 +01:00

Added subscriber: @Inwader77

Alexey commented

2015-12-20 22:07:54 +01:00

![6.png](https://archive.blender.org/developer/F269868/6.png)

Bastien Montagne commented

2016-01-22 19:38:23 +01:00

Added subscriber: @mont29

Bastien Montagne commented

2016-01-22 19:38:23 +01:00

Main issue here was caused by shadow pass being skipped when diffuse was pitch black - makes sense if you only use that pass internally, since it’s useless with black diffuse color, but not when you want shadow pass for itself. Fix for that is incoming.

Issue with picture tex being noisy I still so not understand…

Main issue here was caused by shadow pass being skipped when diffuse was pitch black - makes sense if you only use that pass internally, since it’s useless with black diffuse color, but not when you want shadow pass for itself. Fix for that is incoming. Issue with picture tex being noisy I still so not understand…

Bastien Montagne commented

2016-01-22 22:22:32 +01:00

Texture noise comes from some 'instability' of aniso filtering, which generates some pixels with not exactly 1.0 alpha values like 0.999999940395355…

Enough for this evening! :P

Texture noise comes from some 'instability' of aniso filtering, which generates some pixels with not exactly 1.0 alpha values like `0.999999940395355`… Enough for this evening! :P

Alexey commented

2016-01-22 23:07:39 +01:00

similar behavior we will have in #45214 and in #47033 max saturation material(without texture) - we will see this color in shadow pass,
use texture - we will see max saturation area only. If we use image testure - we will have this noize.

similar behavior we will have in #45214 and in #47033 max saturation material(without texture) - we will see this color in shadow pass, use texture - we will see max saturation area only. If we use image testure - we will have this noize.

Bastien Montagne commented

2016-01-24 11:15:44 +01:00

Changed status from 'Open' to: 'Archived'

Bastien Montagne closed this issue

2016-01-24 11:15:44 +01:00

Bastien Montagne self-assigned this 2016-01-24 11:15:44 +01:00

Bastien Montagne commented

2016-01-24 11:15:44 +01:00

OK, so issue is basically how final shadow pass is being generated by internal, reconstructing it from a diffuse + shadow data. This works OK(ish) in common cases, but will break in all corner cases like pitch black (0.0f), fully saturated (1.0f) colors, etc. Fixing it would most likely require to keep a separated , only-shadow pass, which is totally outside of bug fixing scope - and quite unlikely to ever happen actually, given we do not do any new development for BI… Thanks for the report anyway.

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Shadow pass error: Black shadow #47025