Stroker

Mapping channels are cool. I've got some tutorial ideas running around in my head.

Unfortunately, I'm a Max user. That is, I don't know if other 3d programs use them or in what capacity.

Several questions:
Does your non-Max 3d program have mapping channels?
If so, what 3d prog is it?
Do mapping channels extent to uv mapping in your 3d prog?
Are you interested in some Stroker-style mapping channel stuff?

Blinky2004

hmmm... i don't recall seeing that function in C4D. Could be wrong though. Stu or someone else might know better.

What is the function/purpose of this "mapping channels" Stroker?

Stroker

Hmm...
Blending between different textures...?

One of my favorite uses is to chop out parts that need more texture space with out having to size up the whole texture. Take lips for example. You can chop out the lips, give them more texture space via uv mapping, assign to a different channel, then blend seamlessly onto a face with an alpha.
So the whole head texture could be 500x500 and the lips could be 500x500 as well.

Yeah, blending between textures.

Another good example is having two views of a head: front and side. Lets say that you want to use the shots to texture the head. Well, instead of taking the shots into PS to make one texture, you can use mapping channels and an alpha. Fairly easy to do and seriously cuts down on the PS headaches.

Stroker

Grabbed an old model that I had given up dinking with. Gave it a real quick work over for our purposes here. Did the mapping channel thing real quick. Painted a transparency map, which was just some black + Gaussian Blur (not too hard), and then baked it out.

This is the raw output. The nose and under the chin need some attention. Few other little things.

Can you see how this is a handy technique?

Tomorrow I'll post a render and the easy-sleazy trans map.

Blinky2004

Ooooh ok... ya i know what you mean now man. In C4D that's just done by assigning a specific "alpha" image to a texture.

And then in the Material Manager, you'd assign the textures to "Mix" with the other textures assinged to the same object.

Stroker

Some quick test renders:



Notice the funkiness around the nose. While the texture there does need some work, it is also partly due to vertex shading. Some vertex illumination in there would improve it.

Pretty close, Keeper, but it's a little more complicated than that. Let's take a peek, shall we?

Upper-Left: mapping channel 1
This is the mapping that I want to end up using.

Upper-Right: mapping channel 2
Planar mapping straight on for the front view photo. Notice that it's a bit cock-eyed. The chick in the photo was a bit rotated, so I had to do some compensating. This resulted in a slightly rotated uv mapping.



Lower-Left: mapping channel 3
Side view. Getting the idea here?

Lower-Right: transparency map
This is the transparency map applied to the side view photo. It hides the nose, mouth, and a little bit of the eyes. This is the only work that has been done in PS.

Notice that the transparency map is for the side view. Several reasons. The main reason being that painting a trans map for the front isn't my cup of tea. You can do it the other way around, but I just don't like it.

Since the side view has transparency, this means that some thought has to go into the final material. In the material, the front view is on the "bottom", then the side view is "layered on top" of it. Where the side view is transparent, the front view shows through.

Remember channel 1? Well, when I baked the material, this is the channel that I baked to. As a side note, I made sure that the textures have 100% self-illumination. Didn't see any real need to bake in any scene lighting for this.

Man, I love talking about these kinds of things!
Those stupid little things that few know about, yet can save some serious bacon. Know what I mean? I even went to Google to see what is out there regarding this and found next to nothing.

The final tutorial will be hosted at SomethingLeet. One of the guys over there approached me about writing some 3DS Max tutorials for them, and this is what I decided to babble out.

Hehehe.
I'm all giddy with excitement.
I love this stuff!

Blinky2004

hehe It's nice to see someone so excited about something. Makes me wanna get up and dance! aaa... not really... i don't care much for dancing.

I'm not so sure it's all that different Stroker. Like is said... the same things you've described can be done simply by assigning/using multiple textures to your model, or any part thereof. Alpha settings allow for hard/soft edges/blends, inverse alphas, etc. And each separate texture applied can be mapped in its own specific way.

So i'm not sure i'm completely following you then, because it "seems" like we're talking about the same thing. Just that Max has a different way of doing it...? :B

Rantin Al

So you are a Cinema goer as well Mark. Have you used BP at all?

Materials with transparency, alpha and then you can bung a layer mask on top which can be inverted for good measure. [confused]

Stroker, keep them coming. I can follow most (some \:] ) of your dissertations. There is always some little nugget in amongst the enthusiasm which turns out to be useful. 8))

Am I right in thinking that Bake Texture refers to converting a procedural into an image/ bitmap texture?

Cheers, Al.
(Slippin' an' slidin' away on the Z-axis)

Rick

Very interesting concept here - it gave me an idea to try it with a Poser girl in Photoshop and just using layer masks. A lot of fun. 8)) [bustagut] }P

Stroker

Rick, I see three lesbians. I'm sure Freud would have something to say about that.

That is correct, Rantin.

Mark, I think you have the idea, but I'm not sure if you are taking all the way, though. This is what I hate about not being face-to-face.

Maybe the first rough draft will help clear it up:

Mapping Channels

I need to give it a break as I've been working away like a mad little monkey on it all day long as the kids permit. Fresh eyes do the editing process good.