UnityGLTF not using Roughness map from Metallic Alpha or Green I Blue channel

đŸŒ” Needle Engine
21

If I use that same .Tif file in Blender via the Metallic/Roughness spots with Colour/Alpha respectively and export a GLTF + Separate file, I still get the Metallic put into the Blue channel and Roughness in the Green channel on export in a .png which UnityGLTF doesn’t support (rather than giving me a .png that has roughness in the alpha or spitting out the .Tif file itself)

image.png
image.png862×590 166 KB

by user 103054507105067008

22

Here is that .Tif file separate if it helps for a quick test https://drive.google.com/file/d/1QXShtI0T_jgQqZfUqQ9JGNTZqfsbGHNd/view?usp=share_link

by user 103054507105067008

23

To be clear, the Blue/Green Channel use for roughness/metallic is what the GLTF sample files from Khronos group use like Damaged Helmet so that is why I was stumped at this :thinking:

by user 103054507105067008

24

I’ll check it out

25

In glTF roughness is never in alpha, the PBRGraph shader doesn’t use that either

26

If roughnessFactor is in the file but not imported that would be a bug, yes

27

Thanks, the file material should be identical to the DamagedHelmet example GLTF file from Khronos samples in that the roughness slot is read

by user 103054507105067008

28

@herbstđŸŒ” I have a better repro using a sample GLTF model from Khronos sample models: https://github.com/KhronosGroup/glTF-Sample-Models/tree/master/2.0/DamagedHelmet/glTF
I will also send this to GLTFast
Import this Repro into a project that has UnityGLTF and GLTFast: https://drive.google.com/file/d/1d_cIeId5rvLs73vXJ6WhfRd13U-33Ofb/view?usp=share_link
image.png
image.png

by user 103054507105067008

29

I still don’t get your left picture there

30

PBRGraph doesn’t support roughness in alpha

31

Interestingly when I export those 3 models in Needle, the one on the left that uses the roughness is not using it in Needle

image.png
image.png1111×625 382 KB

by user 103054507105067008

32

middle and right look correct (that’s how the helmet should look) - what’s the bug here?

33

This is a tif using roughness in metallic alpha on UnityGLTF/PBRGraph sliding the roughness shows it working

https://cdn.discordapp.com/attachments/1062782257703702640/1063034512445022308/roughnessslide.gif?ex=65d71b09&is=65c4a609&hm=1555549017c12b3a4e25f68648c063073cc2c91847c6acaf6d74ef1fae4663c3&(image larger than 4 MB)

by user 103054507105067008

34

I’m really not sure why you expect roughness in alpha to work in PBRGraph, it doesn’t

35

that’s by design

36

glTF uses ORM format (Occlusion-Roughness-Metallic in R-G-B)

37

Okay, so this ORM one is correct
roughnessslide2.gif

by user 103054507105067008

38

As I keep saying :smile:

39

Looking at this file now

40

Trying to find out why in the original problem file that the ORM roughness doesn’t work
ORMissue.gif

by user 103054507105067008