I'm still running in several different tangents and still no wiki. I'll have wiki back one of these days, and then I'll astound and amaze with the tutorials that I've been working on.
However, I really want to get this out.
However, you will need access to 3DS Max + Mental Ray and know your way around to follow along. Kind of narrows down the number of people that can pull this technique, which really sucks. But maybe something like this can be hacked in other 3d packages.
One thing I really hate is trying to paint smooth transitions. And when dealing with skins, transitions can be very important. Skin really speaks of the person. Let's say that you have an olive complextion, get moderate sun, and always wear tank tops. There will be slightly broad tans lines down the chest and over the shoulders. I really hate trying to paint those kinds of transitions. Or let's say you are super pale and spend a full day at the beach wearing a one-piece bathing suit. The transitions for something like that will be rather hard.
Ugh!
There-in lies what one of the things that has been on my mind lately. Is there a way to use a renderer and geometry to do the transitions for me? Is there a way to model the lighting/selections/masks without any painting what-so-ever?
I can be done in 3DS Max + Mental Ray. I read how to do this when I random link-hopping and stumbled upon a tutorial for neon lights. After some playing around, I'm pretty sure I narrowed the technique down to the important pieces.
Fire up Max and open up the Render dialog. Assign Mental Ray. In the Indirect Illumination tab, enable Final Gather. For test renders, I usually bring Samples way down, then crank it back up for final output.
Mental Ray with Final Gather turned on.
Now get some object that you want to 'model lighting' onto. For example, the avatar OBJ. Sure. For this, going to need a special material.
Open up the Material Editor and pick a slot. For this slot, you will have to disable the link between Ambient and Diffuse. Make the Ambient colour pure black, and make the Diffuse colour pure white. Slap this material on the avatar.
Now need an object to illuminate things. Go ahead and drag out a plane and face it towards the avatar. Just a regular plane for now just to see how this works.
The illuminating plane needs a different material. Back to the Material Editor and pick a different slot. For this material, make Diffuse + Ambient pure white. Turn on Self-Illumination and make it pure white as well.
One last thing to do is to set up the lighting. Drop in an Omni light and turn on Ambient Only in the Advanced Effects roll-out.
Render that bad boy and hopefully the plane will emit light and light up the avatar.
*If the light emitting plane is obstructing your view in the render, turn off Visible to Camera under Properties.
The real coolness starts when you get to really playing with the light emitting object. Does it have to be a flat plane? Of course not. For example, a torus around the avatar's waist. Or even a Poly/Mesh object with whatever modeling tricks you care to put into it.
There are several things for tweaking:
- The area of the faces of the light emitting object. The more area, the more it lights things up.
- How close the light emitting geometry is to the light receiving geometry. The closer, the brighter.
- In the Omni light, Intensity/Color/Attenuation > Multiplier. This will brighten/darken. An easy way to blow things out.
- The geometric normals of the light emitting poly/mesh object.
- You can also toss in other objects to block light and cast soft shadows.
Getting those things to play nice together to get what you want takes a bit of getting used to. Bit of an art, but modeling light on an object is definitely kind of cool. And, for me, beats painting. Tweak a few verts and it's a whole new mask. Bake it out and take it into Photoshop. One mask to shift the hues a tad around the hips, then another mask to lower saturation underneath the gluts. No real painting, perfect blending. Not bad for moving some verts and 10 seconds of baking.
Hopefully this weekend I'll have some time to play and toss up some practical examples.