UV input nodes behaving differently when used with ParameterSubUV and Param2D

Development Rendering
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1

I have setup a simple PBR material, that I now want to re-mix using different UV Maps. Everything works as expected so far, however I am having trouble with getting height to work. I am providing my UV maps as 8-Bit RGBA images, where only the R and G channels are used for U/V coordinates. I set the texture compression to VectorDisplacementMap, to prevent it from beeing compressed. Finally I’ve added my UV map using a TextureParameterSample2D to my material. I then use the UV coordinates to sample my texture maps using TextureParameterSampleSubUV nodes. Here is how my material looks like:

233975-material-overview.png
233975-material-overview.png772×857 105 KB

The problem is, that I cannot use sub uv samples to generate displacement, since they are not supported as input nodes for vertex, hull or domain shaders. Using the UVs input node of the TextureParameterSample2D node, however, does somehow distort the texture, as if only one component is used. Take a look at the preview of the parameter nodes here:

233976-material-input-node.png
233976-material-input-node.png1091×728 164 KB

Is it possible to use my UV map in this case, somehow? Am I missing something?
Any help is greatly appreciated, so thanks in advance! :slight_smile:

2

Short story, dont use TextureSampleSubUV’s
Just use regular TextureSamples. the only real advantage SubUV’s give is a blending option, but thats only helpful for specific flipbooks in cascade.

Also later on you might want to pack the grayscale images together in RGB but thats another story.

3

For some reasons I am unable to comment here (yet?), so sorry for that non-answer!

Luos :diamonds::

Short story, dont use TextureSampleSubUV’s Just use regular TextureSamples. the only real advantage SubUV’s give is a blending option, but thats only helpful for specific flipbooks in cascade.

Also later on you might want to pack the grayscale images together in RGB but thats another story.

First of all, thanks for your reply. I am aware, that multiple maps can be combined into a single sample for better performance and efficiency, but that’s not what I am looking for. My problem here is, that TextureSamples are getting incorrectly mapped when I use another TextureParameter as input for the UVs pin. If I use a TextureCoordinate, everything works as expected. As for the TextureParameter, only SubUV’s are giving the correct results, which I cannot use for displacements.

4

not really sure whats causing that, I control textures plenty of time trough the use of other textures.
At least, I cant tell with just these images. it could be so many factors.
I’d need more and accurate shots of anything involving all that affecting the texture.