Hi everyone!
I am having a problem i cant figure out..
So i have this ground plane:



Now, i would usually use this method to blend some grass or some other texture to breakup the tiling:
http://www.polycount.com/forum/showp...&postcount=637

But the problem is i am tiling the texture which is part of a uv map. Meaning that i have to facemap the tilling. Any blending images i paint would just tile with the texture. So my question is how do i manage to blend this texuture knowing that it's part of a texture atlas?

Where do you want to blend it? In 3ds max?

Use a second UV channel.

i would like to try in udk mobile... but am a noob with udk.. does it support seperate uv channels?

It definitely does, but I'm not an expert with UDK either.

us a vertex paint shader, that way you can just paint vertex colour in udk, to blend in the grass texture.

thanks for the help! Do you or anybody know if this would be the best method of doing it? Would it bring big drawbacks on performance or something?

Originally Posted by passerby

us a vertex paint shader, that way you can just paint vertex colour in udk, to blend in the grass texture.

but i would need the grass texture be a seperate texture for that. I can't choose any other texture but the one i am using. Unless there is a way to make udk select a different UV space. Of course this would all be solved with the multiple uv's method.. was just wondering if there are any drawbacks on it.

Originally Posted by M1KES

but i would need the grass texture be a seperate texture for that. I can't choose any other texture but the one i am using. Unless there is a way to make udk select a different UV space. Of course this would all be solved with the multiple uv's method.. was just wondering if there are any drawbacks on it.

why cant you use 2 textures?

also yes you could do multiple UV's and blend between the 2 uvsets with vertex paint

This is what you are looking for:
Vertex Blending:

Mesh / Vertex Painting Basics - UDK Tutorials by...

I was wondering this exact thing, so it's fresh in my mind

If you want to have the texture you're going to vertex paint on one sheet just create a separate uv channel and unwrap again (mind you 0/1-1/2 are already taken). Once inside UDK you can use a "Texture Coordinate" node that can switch between UV channels.

With multiple UV sets and careful blending, you can have completely seamless environments.

you can change the UV channel in the UV coordinate node, though I don't know if that works in mobile.

the main down side to multiple UV channels is that it is stored as addition geometry information. If you have a dense mesh that you exspect will be rendered often(such as mountains, terrain or buildings) it will chew through your geometry budget.

though one extra UV shouldn't be a big problem, any more you might start seeing problems.

here is the UDN document for texture blending but i think that's more for detailing

http://udn.epicgames.com/Three/Mobil...xture Blending

mobile does support some vertex painting in the newer versions, which could work but will give you that fuzzy transition between textures, and can get expensive as well.



I recommend taking a look at the citadel mobile map that comes with UDK. they use multiple materials, tiling textures and carefull overlapping of UVs to create terrain. the end result looks great but requires a lot of pre-planning in the modeling and UV phase.

Really great answers here guys! Got it to work perfectly! Thank you for the help!
I would like to know if it is possible to show the the painted vertices within the 3ds max viewport? Like can i paint the the vertices in UDK and show up like that in max?

Or better yet... doing the vertex painting in 3ds max and exporting with the data to udk. Is that possible?

It's possible, but annoying.
You'd have to use ShaderFX in 3dsmax in order to create a FX shader for the viewport that imitates the behavior of your UDK shader. That way you can paint in Max then export that mesh out to UDK.

It's possible, but annoying.

You also lose one of the benefits of vertex painting your texture blends: variety. If you're importing your mesh with vertex colors, then every single instance of this mesh will have the same texture transitions. Vertex painting in-engine is a much better option, since you get whatever variety/specificity you need, with negligible overhead.

Thanks for the input guys! Yeah, i guess i'll do my vertex painting in UDK then. Just one question.. is it possible to view the painted mesh from UDK in max?

you could do the vertex painting in max or udk, dosnt matter.

the nice part about doing it in udk is that each instance of the mesh can have differnt vertex colours

I got to get the vertex paint to work in 3ds max with the modifier. But it just show up as black.. Doesn't show the blending.
Another question I was wondering is if it is possible to show one of the image channels in max? Like you do in UDK..