Second UV channels?
I've been doing environment art for quite a while, but have yet to really ever use a second UV channel for anything other than lightmaps. I see some people use second UV channels to add maybe some leaks or something to a mesh. What are some other use cases?
Im working with some building meshes right now that use a tiling texture over them, but also have painted designs on top of the tiling texture in spots. Im just duplicating some faces on the mesh, offsetting them by a very small amount and adding another material with my painted designs on them (with alpha), so it looks like it painted on the mesh itself and still shows my tiling material under it. Is this a case for a second UV channel? How would that work with also showing the tiling material underneath?
Replies
Yes, that's a good use case.
Make a material that blends them however you need and you'll get what you need
quite a lot of uses not all are related to mapping, blending maps, overlays to break up tiling, baked shadow maps, encoding screen space coordinates for camera facing billboards, vertex weighting for drop in meshes (1 means the vert is shifted to the floor for example) there are a lot of uses for an additional per vertex x,y,z value.
speedtree uses extra UV channels to store pivots for animation.
@poopipe @Klunk ahh, makes sense. any links for using blending with a second UV channel? What would I do in my case with the painting designs over the tiling textures I have?
any particular app ?
@Klunk I basically use Maya/UE.
doing it in unreal is the easiest
this seems like a good tutorial showing how you might use this technique
For unreal just change the channel in a texcoord node and plug it into a texture in your material
all extremely helpful. thank you.