Problems with shadow pass and mirrored UV's

[aphexx]

hi, i'd like to ask, if there are any restrictions in vray, concerning mirrored UV's when rendering passes.
the FULL path is always rendered correct. but the shadow patch give us a white color on one side of the character, we have to render.
since these chars have the UV's we also use in our gameengine, they are mirrored.

the material has a vraynormalmap in the bump slot.

[Morbid Angel]

hi, i'd like to ask, if there are any restrictions in vray, concerning mirrored UV's when rendering passes.
the FULL path is always rendered correct. but the shadow patch give us a white color on one side of the character, we have to render.
since these chars have the UV's we also use in our gameengine, they are mirrored.

the material has a vraynormalmap in the bump slot.

are they just mirrored or are they overlapping?

[vlado]

Can you post an image of what this looks like?

Best regards,
Vlado

[aphexx]

they are both mirrored and overlapping i think.

[aphexx]

the shadow pass looks like this.
the background made blue only for this post.
i currently cant show more of this scene.

[Morbid Angel]

the shadow pass looks like this.
the background made blue only for this post.
i currently cant show more of this scene.

well thats your problem. You cannot have overlapping uv's. Also flipped uv's will produce reversed result.
I think for your purpose you should only bake half of the model and then just apply the map to the whole model and it will work.

[aphexx]

ah, thank you. i didnt know that.we are all not that much into rendering here.
i will give your answer to our char artists so that they can fix this issue.
i wonder, why the full renderpasses look ok then

[Morbid Angel]

ah, thank you. i didnt know that.we are all not that much into rendering here.
i will give your answer to our char artists so that they can fix this issue.
i wonder, why the full renderpasses look ok then

well if for example you were to duplicate the same mesh and leave it at the same space but invert its normals and render it...you will get a bad render also since there will be two meshes occupying the same space. The same thing happens with the uv's. The renderer does not know which side to apply the pixels to.
I guess there could be a feature for user to specify which side of normals to bake to uv and ignore the opposite side...Vlado?