Substance Painter Normals in Vray

[racoonart]

I'm currently trying out Substance painter and I'm facing a problem with Normal maps.
There are two meshes, a low res and a high res:

I'm baking the high res details down to the low res geometry which looks fine so far in Sp:

Now when I load the normal map in Max and try to render in Vray 3.30.05 there are several issues popping up:
It's a vray material with a vrayNormalMap loading the normal map at gamma 1.0, bump strength is set to 100.0

I assumed that the issue lies somewhere in the different calculations of tangents & binormals, so I tried tried both exporting and not exporting tangents and binormals (+ de-/activating calculation in substance painter) - but that didn't make much difference.

Sidenote: Iray in substance painter isn't without flaws either but at least it looks a bit better, especially because there are no "holes" .


Any help with this would be appreciated.

[vlado]

Can you post the geometry and the normal map? I'm not sure right away what's the problem.

Best regards,
Vlado

[Moriah]

Have you tried adding a Edit Normals or Edit Poly on top of your object? When i have issues with normals (specially coming from other softwares) it solves them most of the time.

[racoonart]

Can you post the geometry and the normal map? I'm not sure right away what's the problem.

Sure, here you go Max file (max 2014) with normal map included

Have you tried adding a Edit Normals or Edit Poly on top of your object? When i have issues with normals (specially coming from other softwares) it solves them most of the time.

Tried that but doesn't make any difference =/

[racoonart]

Just for completeness: Seems to be a vray-only issue, at least the holes. I tried rendering it with corona and it looks "better", but they also recalculate the tangents and binormals on the fly with some unknown method so it's not without flaws - I guess vray does the same?


Maybe it a mikkT tangent basis mode somewhere could come in handy?

[vlado]

Ok, will take a look at the scene; why don't you bake the normals in object or world space btw?

Best regards,
Vlado

[racoonart]

I may be missing something but I don't see how/if this would be beneficial (I'm always thankful for more information). World or object space may work for static assets but as soon as there is some deforming/animation involved I'd have to use tangent-space anyways. I'm not really into this whole games thing (yet) but I didn't see a lot of assets using anything different than tangent-space normal maps.

[vlado]

Object space will work for transforming assets just fine; tangent space is good for deforming assets, but object space might get you more precise results without the problems that you have above due to differences in the way render engines compute the tangent space. That particular part above, I'm not sure how you want to deform it

Best regards,
Vlado

[racoonart]

Ah I see. Ok, it makes sense this way, thanks for clarifying. I was indeed referring to deforming meshes, like characters or some other rigged and skinned object.
Agreed that the object above is not really a classical example of a game asset, especially not for a deforming one But it was a simple enough object for bug hunting and testrenderings. I'll make some tests with object space and if we can utilize it, but apart from that the issue with binormals and tangents is of course still present in all deforming assets =/.

[vlado]

It's a bug that I introduced in the latest service pack; will fix it for the next in a couple of weeks but in the mean time, you can set the environment variable VRAY_OLD_BUMP_REFL=1 and it will render better - see attachment.

Best regards,
Vlado

[racoonart]

Great! Thanks for the info and the temporary fix