Vertex Paint vs Decaling vs finding better solution

ThinkLogical

Hi, I am pretty much a newbie to all ends, this forum, game development, and especially using UDK. I have several years in basic modeling and texturing in Maya. I am really interested in being able to add some grime, dirt, or what not on my walls, which I plan to have a tiled texture, such as a brick wall. My theory is to have the tiled texture to tile more than the grime, dirt, or what not texture. Something like in the ratio of 8:1 as an example. The only method that I have been taught was to was to paint everything in Photoshop, but that limits the texture from not being able to be used on other walls that have different UV maps. I heard of Vertex Painting, or adding decaling. However, with Vertex Painting, I cannot grasp why someone would destroy his hard work trying to keep his poly count as low as possible to only find out that Vertex Painting would not produce good results with a 4 vertex planar poly as oppose to a 4x4 vertex planar poly? Seriously? Come on; its planar for God's sake!!! .... and the option with adding decals, isn't that just adding more poly's as well?

So with these delima's, what would be the best solution?

chrisradsby

Well first off, it's up to you, it'll always come with a cost, if it's not extra polys it's extra in shader costs or memory for textures. But you have a couple of options:

1. Add more polys, it won't hurt. If you're lodding things however then you need to figure out a solution to fix that. Which is pretty easy as well.

2. Don't use vertex color for you blending, just use blending using Masks.
IE , you have two materials on one planar surface and the texture mask decides where they should blend. The smoothness of the blend is also determined by the mask.

There are more solutions ofcourse but all these kind of depends on your current technical skill with the UDK Materials and Shaders.

ThinkLogical

I appreciate your help. I have started looking into this with Maya, but most of the search results are coming back with Vertex Coloring, even though I have typed: texture blending mask with Maya. Also, while finding out that you can export BSP brushes to FBX, I realize the problem I was having with BSP brushes tilling so badly. This is because, when creating objects through BSP brushes, the UV's are mapped as individual faces and the layout is huge. So big, that they are laid out even bigger then the -1 to +1 UV coordinate space. So basically, when I would try attempting to make a texture blending material, the mask would tile terribly as well.

What I really need is something that allows me to tile a tiling texture such as brick, grass, or dirt etc. but for the mask not to tile and fit within the 0 to 1 UV coordinate space. Is there any method of being able to do that with either static meshes or BSP, preferably BSP?

chrisradsby

Well if you get more into the material editor then yes there is a way so that you can tile your masks or different textures independently. I don't have a node-example for you though but it is doable.

r4ptur3

try looking into multiple UV sets. use the UV set editor in Maya, then specify what channel you want to use in UDK through the material (texture coordinate node). It sounds like you are trying to vertex blend in Maya -- don't even bother trying. All the vertex painting and material setep is much easier to do in UDK.

Synaesthesia

Chris Albeluhn covers this topic pretty well. Give his tutorial a read and see if it helps.

Blubberblase

since you are needing a second unique uv channel for lightmaps anyway just use that for your mask texture or for an overlay grime texture, you can also use world aligned textures which project the textures onto your meshes independant of uvs, it's quite costly though i think, i have been using both techniques combined for medieval walls and it works quite well, the second uv channel is used for grime that is the same on all meshes and the world aligned textures are added for diversity.