Multilayer UV Map Support

Game Engine Game Engine Support and Discussion
1

I think I remember reading somewhere that Blender supports multilayered UV maps, but my memory on this subject is so vague so im sure im probably wrong. Anyway, I notice that on large meshes (like terrain for example) I have to tile a given texture in order to keep the resolution at a decent level, this way the textures dont look blurred or pixelated. I’ve been dabbling into renderbaking a lot lately to work on some new levels for MGP, and I was wondering if you guys could help me out on a few issues im having.

  1. If Blender does support Multilayer UV maps, is there any way I can add a shadow bake layer over tiled textures? If so, how? I’ve searched the web for tutorials on this subject and I cant find any! If someone could point me to a good tutorial I would be very appreciative.

  2. How many layers can I have on a given mesh, and what are my limitations as far as alpha mapping is concerned? Will I have that strange alpha map bug between layers?

Edit:
Im pretty sure Blender supports multilayer UV mapping because I remember the ball on bmud’s Ozone Forces. It had a reflective layer over the yingyang texture on the ball. How did he achieve this?

2
  1. you could use your tiled texture one UV and bake the shadows on second. so you have low res shadows and high res texture.
  2. Apparently you can have 3 if your graphics card supports it (mine supports two).
    Actually the whole multiple UV thing is a bit of a bodge…
    theres a thread here http://blenderartists.org/forum/showthread.php?t=79516&highlight=multiple+UVs
    Here is a thread where I figured out how the baking works. http://blenderartists.org/forum/showthread.php?t=103092&highlight=bake+texture
    As to Alphas you can do interesting things, especially by using a UV animating script on one UV and having a static UV with an Alpha. I used it for smoke and it looked pretty cool.

My experience is this is pretty frustrating until you know what your doing…

3

Whenever I bake something thats tiled, I have to unwrap it differently to get it to bake correctly. How can I get this to quit?

EDIT: To be more specific, I have a grass texture that is applied every face. I have to unwrap it differently to render bake it. How can I differ this?

4

If your tiling then many faces can occupy the same area of the UV texture. If your baking each face must have its own bit of texture to bake on.

If you bake the shadows separately from the tiled texture on a grey texture and then multiply it with your tiled texture you have the best of both worlds … but I’m off to bed zzzzzzzzz

5

There are several tuts for doing this and many ways to use it,smile.

OK, here is Snailrose’s Light mapping tut:
http://www.continuousphysics.com/lightmap/LightMapTutorial.html

I dont see any of my other links just now, but there is an introduction in the wiki on blender.or. Thats probably the best place to start with this.

You can also. bake to separate images and then combine them in your graphics program, changing the opacity etc to give you the look you are after.

But for shadows, the link above is probably the best?

6

I must’ve been using the wrong search terms. Thanks for all the info and links, I really appreciate it =)

7

Im pretty sure Blender supports multilayer UV mapping because I remember the ball on bmud’s Ozone Forces. It had a reflective layer over the yingyang texture on the ball. How did he achieve this?

Im not sure how he did it, but you can use reflections in realtime texture mapping? Maybe.

Its in the uv image editor window, under images. Its kind of fun to use.