UV Channels?

[tehfailsafe]

Been learning more about UDK and modular building for games, and was curious if Octane can support different textures on different UV channels for texture layering? Since vram space is so limited, I could make something with many repetitive shapes like a building using 1 UV channel with duplicated modular geometry, then add a dirt/grime image texture to overlay on top of it all using the 2nd UV channel so it doesn't repeat the way the geometry and base texture repeat.

This would let me use a say 2048x2048 texture for like bricks/concrete, then add a "messy" layer on top without needing a super high res base texture. If I were to try and map the whole building onto 1 UV channel for the bricks the texture would have to be HUUUGE to get the same quality resolution as the modular piece using 2048.

[kubo]

well right now it doesn't do it, but I do all the time the process you are describing just with one channel, it requires a little more tweaking, but it works. Just play with the scale of the second "channel" aka the dirt, and it comes out pretty good, use a mix or multiply node.

[tehfailsafe]

Ah, interesting.
I was hoping to reuse lots of the modules ( wall, corner, door, etc ) to build multiple buildings. So each module has it's own bit of on the UV map. But that means lots of textures get duplicated. To break it up I was hoping to re-uv map the whole object as 1 new texture that is just the dirt and grime to help break up the repetition. This way I could also bring the object into mudbox/zbrush and paint there without any overlapping UVs.

Does your way allow you the control to put say dark rusty blotchyness in the crevices ( like a dirty AO )? Or is it more random when your playing with scales?

[matej]

A million +1s!!

I just hope RS has per texture node UV coordinates in mind, when they refactor the export/import & scene holding file. This is a very usable feature and it also let's you save RAM!

[kubo]

in that case I paint the dirt map, which would cover the whole object, then I would use it as a multiply over the base "brick" texture which would be needed to scale down say 10x time (change the scale to 10), and then the brick (or whatever other base texture would have a more random look. You might have to tweak the brick a little but it works ok. It does not work for some situations, but for most it does.