alpha maps in terrain textures

[Rhinokio]

hello i was wonderin if it was possible to have an alpha in your terrain texture to modify how it blends over another terrain layer, say my layer 1 is sand , and i make a rocky layer, and alpha around all the rocks, so when i layer it over the sand you see the sand thru the alph sections of the texture, we could do this with the warhammer online engine and was wondering if it was possible in unreal.

i tried just making a texture with an alpha in it, but when painting terrain it seems to do nothing.

[ambershee]

I don't believe you can use alpha in the texture itself on terrain; any blending should be handled when painting on the terrain itself, try painting using weaker brush strengths.

[Rhinokio]

yeah thats what i feared, but is not what i was after, weaker brushes just lowere the opacity of the whole texture, what i would like would be the texture at full str but the alpha of the texture being transparent. perhaps its possible to be modified in script.

[nfollmer]

Why can't you create a rock/grass texture in photoshop (or whatever you use) and then just paint that texture where you want the rocks? That ensures a clean paint.

[Rhinokio]

cause then you would need to make rock/grass rock/dirt rock/snow rock/snow/dirt rock/mud theres all kinds of ways to work around it i'm just asking if its possible with the tech. i mean we had it on warhammeronline in that crummy gamebryo engine. so i figure it should be possible in udk, i was just checking to see if it is already there before i think about trying to modify it

[Rhinokio]

heres a shot of the feature at work in warhammer.

[gokzor]

Yes you could use a Larp (linear interpolation) and combine the maps. If im geting what you mean.

[Xendance]

You could use 3d rock smeshes and use them as foliage with the terrain material.

edit: just saw your pic, dunno if you can do that.

[Rhinokio]

yeah i will be doing some rocks as foilage also, but just thought this would be a nice feature, on warhammer we used it for tree roots ground cover flowers, leaves, snow, oh well! cest la vie!

[gokzor]

Here is what i think your asking?

[gokzor]

My bad i wasnt reading terrain texture sorry!

[Rhinokio]

that would be one way of doing it, and may work in a pinch, but even thats not ideal say you have a terrain painted with 3 layers mud / grass / sand and they are all blended, with your method gok if you want rocky bits over each of those terrains you would have to make a shader for each of them, 3 shaders, and ad 3 more terrain layers.
just for the rocks,

but still if it is the only way to do it, then it would be better than nothing.

i appreciate you taking the time to write that up tho.

[AreDub3D]

Can't you still only have 3 or 4 terrain materials in UDK? Can it now handle more?

I think Rhinokio wants to do this without adding another material ...

[musilowski]

How about decals projected on the terrain? In case you've used all the terrain material "slots".