Weird lines with normal map after importing mesh from Max to Maya

Peksio

Hey, I have a problem with mesh from Max in Maya. Mesh was modelled in Max, then baked in Marmoset.

Then I imported this model to Maya (with checked option "Unlock Normals" in fbx settings so maya won't recompute normals) and mesh overall looks nice, but in many places are this weird lines. Unlocking normals is ofcourse destroying whole mesh

Screenshot:

Maybe someone have encountered problem similar to this ?

Thanks

demigodssw

Try locking your normals in max and then importing it to maya.

Peksio

Hi. I am sorry for huge delay but I had some other problems to fix

But this one stayed with me. I tried many diffrent things but I cannot get to work models from Max in Maya. No matter how I try to import it, or which script or option I use for unlocking normals, those lines still occur. At every model.

But there have to be something that I can do about it ! (this locking normals in max didn't help, I asked several max users and they didn't have any idea what I mean)

Peksio

I wanted to bump this thread because I was looking on the internet but I still coudn't find anything about this. And it's driving me crazy, it is absurd!

Anyone, anything ?

Alvor

this might have to do with left vs right handed tangent spaces, which are handled differently in Max (left H) and Maya (Right H). A quick test would be to expand the shape node attribute in Maya and switch from right to left.

Peksio

If you are talking about this on screen below, then it isn't working

Alvor

yep, that's what I had in mind. If you activate the radio "button" to left handed, you'll see its normal mapping displayed differently. Depends how Marmoset baked that initially. Another option is to just try inverting the Y/green channel of the normal map, and see if that change things. If neither works, then you probably have some UV and/or smoothing groups (hard edges in maya) to readjust before redoing the bake.

Alex_J

Post the normal map. Do you see the seams there?

This looks like an issue I get sometimes if I forget to smooth edges on a model before baking. I don't think inverting the normal map will fix this -- this isn't like the entire thing is shading the wrong way, it's just some bad edges.

In Maya, try unlocking the normals and then using soften/harden edges. I think the thing to check is, moving the model from Max to Maya, what is going on with the smoothing groups? Does the model look the same in that regard?

To make things easy, you may just apply your smoothing in each program, export, and bake new textures with output for the relavent tangent space in each. This doesn't answer the question of why does this happen, but it gives you correct maps for each program anyway.