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View Full Version : Multiple UVW same material in BP v3?

EricChadwick
10-20-2006, 03:04 PM
Anyone know if the new version 3 of Body Paint 3D will support the use of multiple UVW sets within the same material?

I need to paint an untiled mask between two tiled color textures, for landscape blending in a real-time 3D application (like a game engine, but not really a game). Here's an example, created in 3ds Max:
http://www.ericchadwick.com/examples/images/2006.10.10_landscape_sm.jpg (http://www.ericchadwick.com/examples/images/2006.10.10_landscape.jpg)

One 1024^2 color texture (rocks) is tiled in UV space 15 times across the landscape, the other 1024^2 color texture (greenery) is tiled 8 times using its own UV space, and I need to paint a 1024^2 detailed grayscale mask (blending between rocks and greenery) using its own non-tiled UV space.

Only way I can figure out how to do this is by pre-tiling the textures into a massive-resolution file in Photoshop... 1024 x 15 = 15360 wide... painting the mask at this massive res, then rescaling it down to my 1024^2 output size.

But I'd prefer to do this painting in 3D, since the shape of the landscape should dictate the shape of the mask.

Anyone know of a 3D painting tool that can accomplish this kind of task?
Srek
10-20-2006, 03:19 PM
You can use on UV set per material tag. The order of tags in the OM determines which uses which.
Cheers
Björn
EricChadwick
10-20-2006, 03:50 PM
Thanks Björn.

So I guess that means I won't be able to do it with BP3D? If I set one material to be rocks, another to be greenery, I can set them to each use a different UV set... but I guess I can't paint a mask between them, unless I use the transparency channel of the upper material, which means I'm using the same UV?
Per-Anders
10-20-2006, 08:24 PM
Thanks Björn.

So I guess that means I won't be able to do it with BP3D? If I set one material to be rocks, another to be greenery, I can set them to each use a different UV set... but I guess I can't paint a mask between them, unless I use the transparency channel of the upper material, which means I'm using the same UV?

Hi sure this is possible (always has been afaik), I think you're maybe not following how textures work in C4D/Bodypaint (or perhaps aren't clear on precisely what it is you want to be happening). Every Texture tag can have it's own UV's. I'm not sure why you would actually want to have multiple uv sets on a single bitmap though, but that's easily done by sharing the same bitmap between multiple textures on your object (because it will simply use the uv set of the texture tag that you're painting into to paint onto the canvas), there is one limitation with painting to the same bitmap rather than multiple bitmaps and that is that when painting multiple textures and uv's at once the upper most selected UV will win, i.e. unless you have that top most texture restricted and you've got it selected it will paint to that one and not the other when painting in viewport. you will also find that alpha work frequently is better to paint in the color channel (so it's clearly visible) as otherwise it's a bit of painting in the dark in the viewport.
EricChadwick
10-20-2006, 08:40 PM
Sorry, I'm not explaining this very clearly.

http://www.ericchadwick.com/examples/images/non-tiled_mask_example.jpg

This is a single object with three bitmaps. Rock and greenery bitmaps each use a different XY-repeating UV set, while the mask uses a non-repeating UV set.

Tech support is telling me that within a single material, each of its bitmaps (color, luminance, transparency, etc.) can only use the same UV set. But each material can use a different UV set, and BP3D can display multiple materials at once in its viewport.

Problem for me is I'd like my mask to be the transparency of one material, so I can paint my mask to follow various features of each of the two color maps, like have rocks in between the farm plots, or have masked-rock-shapes follow the natural curvature of the rocks.

But they're saying this isn't possible, they allow only one UV set per material.

Thanks for your help!
Per-Anders
10-20-2006, 09:11 PM
Ah ok, then yes they are correct (although it is possible to use multiple non uv projections within a single material), you would not be able to paint the alpha blend into the material that way directly in Bodypaint with each layer having it's own UV set sadly. You would be able to paint the alpha into another material though (with it's own uvs) and combine the results back together again in Max, but that's all.
JDP
10-20-2006, 09:18 PM
Sorry eric, I removed the info from here before you replied as you won't be able to see results while painting with this method, if you want me to repeat it let me know.

cheers, JDP.
EricChadwick
10-20-2006, 09:23 PM
Oooh, that sounds nice JDP. I just downloaded the demo, so I'll have a play with this.

Even if it doesn't, Per-Anders' method might work too. Although that may be hard to see while I paint, using 3 different blend types to blend the three material on one another (add, mult, 50%lerp, or something).

Anyone know if the Max plugin exports multiple UVs?
lllab
10-21-2006, 09:13 PM
having multiple UVs in ONE material is also a long wish for me.

it would be so grat to be able to choose which uvw tag is used for each shader/bitmap parameter.

cheers
stefan
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