TGA Images with any alpha value smaller than one behaves unexpected #89034

New Issue

Frederik Steinmetz · 2021-06-10T14:56:28+02:00

2021-06-10 14:56:28 +02:00

System Information
Operating system: Win10, 64
Graphics card: GTX 980

Blender Version
Broken: 2.80, 2.93, but I don't think it ever worked.

Short description of error
When importing .tga image file, Blender doesn't output any color information where the alpha channel is 0.
When set to straight, I think the RGB gets multiplied by the alpha value. It's darkening the image a lot, pure black when alpha is 0.
When set to pre-multiplied where the alpha channel is < 1, there are only grayscale values, no color information anymore.

I use tga, because it's easy to separate color from RGB and use the alpha channel as a map in game engines, so it would be great if Blender could treat .tga like for example Unity does. Whether the alpha is transparent, or just another channel is optional.

Exact steps for others to reproduce the error
Import any .tga image with an alpha channel that has at least some areas where the alpha is smaller than 1.

**System Information** Operating system: Win10, 64 Graphics card: GTX 980 **Blender Version** Broken: 2.80, 2.93, but I don't think it ever worked. **Short description of error** When importing .tga image file, Blender doesn't output any color information where the alpha channel is 0. When set to straight, I think the RGB gets multiplied by the alpha value. It's darkening the image a lot, pure black when alpha is 0. When set to pre-multiplied where the alpha channel is < 1, there are only grayscale values, no color information anymore. I use tga, because it's easy to separate color from RGB and use the alpha channel as a map in game engines, so it would be great if Blender could treat .tga like for example Unity does. Whether the alpha is transparent, or just another channel is optional. **Exact steps for others to reproduce the error** Import any .tga image with an alpha channel that has at least some areas where the alpha is smaller than 1.![Scratches.tga](https://archive.blender.org/developer/F10165679/Scratches.tga)

Frederik Steinmetz commented

2021-06-10 14:56:28 +02:00

Added subscriber: @FrederikSteinmetz

Philipp Oeser commented

2021-07-09 14:29:40 +02:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2021-07-09 14:29:40 +02:00

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

Philipp Oeser commented

2021-07-09 14:29:40 +02:00

Isnt this what Channel Packed is for?
(this seems to display/render correctly for me in both eevee and cycles)

#89034.blend

However, I am also confused why Channel Packed is still displaying like Straight in the Image Editor, will check...
But lets first see if Channel Packed suits your needs.

Isnt this what `Channel Packed` is for? (this seems to display/render correctly for me in both eevee and cycles) [#89034.blend](https://archive.blender.org/developer/F10218052/T89034.blend) ![image.png](https://archive.blender.org/developer/F10218053/image.png) However, I am also confused why Channel Packed is still displaying like Straight in the Image Editor, will check... But lets first see if `Channel Packed` suits your needs.

blender-admin commented

2021-07-09 16:51:46 +02:00

This issue was referenced by 563fdaaa39

This issue was referenced by 563fdaaa397bbe5e3fdc66cb72db15af16e0fb1a

blender-admin commented

2021-07-09 16:51:46 +02:00

This issue was referenced by 53cf8e83b3

This issue was referenced by 53cf8e83b37da5cc4de2ef9bd6e4df9e81c976ac

Philipp Oeser commented

2021-07-09 17:15:50 +02:00

regarding Channel Packed images still displaying with alpha affecting rgb in the Image Editor (and elsewhere, excluding "real" rendering the textures): put up a patch here D11871: Fix channel packed images display in the Image/Node editor

regarding Channel Packed images still displaying with alpha affecting rgb in the Image Editor (and elsewhere, excluding "real" rendering the textures): put up a patch here [D11871: Fix channel packed images display in the Image/Node editor](https://archive.blender.org/developer/D11871)

Frederik Steinmetz commented

2021-07-12 12:02:07 +02:00

Added subscriber: @philipp-14

Frederik Steinmetz commented

2021-07-12 12:02:07 +02:00

Philipp Oeser (lichtwerk) Yes, the channel packed option fixes my issue. No idea how I missed this, sorry.

Philipp Oeser commented

2021-07-12 12:33:45 +02:00

Removed subscriber: @philipp-14

Philipp Oeser commented

2021-07-12 12:33:45 +02:00

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

Philipp Oeser closed this issue

2021-07-12 12:33:45 +02:00

Philipp Oeser self-assigned this 2021-07-12 12:33:45 +02:00

Philipp Oeser commented

2021-07-12 12:33:45 +02:00

@FrederikSteinmetz : OK, thx getting back, will close then (since D11871 has also landed, so Channel Packed should work correctly in the Image Editor as well)

@FrederikSteinmetz : OK, thx getting back, will close then (since [D11871](https://archive.blender.org/developer/D11871) has also landed, so Channel Packed should work correctly in the Image Editor as well)

Falk David referenced this issue

2023-02-10 13:03:23 +01:00

Blender LTS: Maintenance Task 2.93 #88449

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TGA Images with any alpha value smaller than one behaves unexpected #89034