Texture Channel Packing

[Nijiem Arih]

I'm currently investigating texture channel packing and am noticing some differences in visual results based off of weather a texture is packed in an R, G, or B channel vs. the Alpha channel. Is this an expected outcome?

Below is a test I've done with different texture channel packs for Smoothness


The materials are all running the exact same Albedo, Normal, Metal, and Occlusion maps
The test for A, R, G, and B are all running texture maps exported from the same PSD source file. Each map only includes information in its respective channel (ie: R only contains Smoothness information in the Red Channel of the texture, and nothing else in all other channels)

All textures are .tga, 2048x2048. R, G, and B are 24-bit images, while A is 32-bit (to allow for alpha channel exporting).

Anyone have any insight here?

[Amplify_Borba]

Hello! If the data is exactly the same, the results should be similar, unless there are some compression issues or the texture is not linear.

That being said, it does not appear to be an ASE related issue, so I'm not quite sure how we can assist you with this, as this forum is meant for product support. Without taking a look at the shader and textures we can't help you any further, but feel free to share a sample with us so that we can examine it on our side and provide better insight on what could be the issue.

[Nijiem Arih]

My channel packed textures were not set to Linear.

Thank you for catching my oversight!

[Nijiem Arih]

Is there a way to check if the texture being input is Linear — similar to when the Normal Map flag is checked?

[Amplify_Borba]

No problem! Unfortunately, this is not possible to check via ASE, as it will only be possible to do so through a script.

The TextureImporter has a sRGBTexture boolean value that indicates whether a texture is linear or not, you can find more information in this Unity Manual page.

Please let me know if you have any further questions, thanks!