Triplanar Normal map problem.

[duaxiong]

Having an issue with the way vray is calculating highlights when running the normal map texture through a triplanar node.

First image is using the surface's UVs; the result is as expected.

The second image runs the same normal map through a triplanar node; the result is the highlights are not rendered correctly.

Is this a bug or am I doing something wrong?

[nikolay.kusht]

Could you tell us in more details why do you think the there is an issue with the highlights when using Triplanar texture and what exactly do you expect as an result.

Please note the that the VRayTriplanarTex works by projecting one or more textures along the object-space axes of the object.

[duaxiong]

As you can see from the graph, both are using the same texture map...the only difference is the triplanar node and a bit of scaling added to the second render.
The way that the scratches are being lit should be more or less the same in both images, but they are not.

The texture is random lines going in all directions. I am trying to simulate the micro-scratches you might find in car paint.
Reference image: http://www.autogeekonline.net/galler...camino_029.jpg

In the left UV mapped method, the scratches are being lit in a circular pattern around the highlight; this is correct.

In the right triplanar mapped method, the scratches are lit in a star-like pattern radiating out from the center of the highlight; random scratches would not look like this.

[nikolay.kusht]

Thanks for the details. I think I got what you are saying but it would be best if you could send us your scene in order to reproduce the same results here.

[matthew999]

i have the same issue here, im not sure triplaner works very well with normalmaps tbh

https://forums.chaosgroup.com/forum/...ffected-by-uvs

https://forums.chaosgroup.com/forum/...inge-artifacts

thanks

matt

[nikolay.kusht]

Thanks for the feedback. Unfortunately the issue with the normal mapping producing strainge artifacts is still unresolved.

[duaxiong]

After some further testing, I think I know what may be causing this.

It seems to be the fact that triplanar is using directional projections; on the "front" side of the projection, it looks fine, but if you flip the model over to the other side, the direction will be reversed. This somehow messes up the way the highlights are drawn.

Below are two examples of this effect; notice how different the highlights are between the two. More interesting is how different the highlights are on the same triplanar mapped sphere.

[duaxiong]

Attached is a Maya 2018 file of the above example.

If my idea is correct, then to fix this means triplanar would somehow need to reference surface normals for projection direction for a more cube-like projection.

[nikolay.kusht]

Thank you for the provided files. I will take a look and I will report to our Dev Team what you have found.

[matthew999]

its a shame this is still not fixed even in vray next, it would be really good to use normal maps and vray triplanar

[smoke91]

Dear Vray Developers,

I can still reproduce this problem right now. I made a video showing the problem. In the case i am not doing something wrong in the shader setup in maya, this seems to be a bug with VrayTriplanar.

Here is the Video showing the problem:

This feature is working completely fine in the 3DsMax Version of the Vray Plugin with the following nodegraph:



As mentioned in the Video the Scene file and the normalmap are attached to this post. If I am not doing something wrong. Please fix this bug!

[francomanko]

did anything get resolved with this?

[thescopeteam]

still does not work with Next 4.3

here is the reason why it does not work, or does it work? how can we convert tangent space normal into screen space or world space maps?

https://medium.com/@bgolus/normal-ma...r-10bf39dca05a

[XavBo]

The triplanar work just perfect !
Should work.

[seandunderdale]

Can we get a definitive yes or no whether normal maps and vray tri-planar are working correctly? Ive had some conversations that suggest it is not working properly. It renders, but once you dig a bit deeper, the normals are doing weird things.