Opacity?

[Xeon18]

I would like to use opacity on some of my texture presumably my shadows to lighten them a bit and do not wish to go back and for them in Photoshop. How do I use opacity in Maya?

[SpiralFace]

now are you talking about your in render cast shadows, or shadows that you paint onto the texture?

Alot of this depends highly on what kind of light set up, and settings you've applied to your lights, and your cast shadows.

Because shadows on the texture from things like bump/ normal maps act a little bit differently then cast shadows from your engine.

Overall, it mainly depends on your light set up more then any kind of "shadow control" on its own.

This is because your shadow is calculated as a result to the lights you have set up in the scene.

Without getting into a whole lecture on proper light set up, learn that there is a basic system known as the "3 point light" set up.

The first light is your Key light. This light is your main light in the scene, and should be the only light you use to cast shadows from. It is to represent your main light source in your scene.

The second light would be considerer your "Fill" light. This light is meant to represent the "bounce" light in your room and is used to "fill out" the lightened parts of your model, without necessarily being as strong as your key light. In a situation where you are using cast shadows, this light will be the main way you will "soften" your cast shadows.

The third light is your "bounce" light, or "rim" light. This light is placed below the model and projects light up from the ground. This light represents light that bounces from the floor to very softly "round out" those parts of the model that face away from your lights.

Thats the jist of it, but you can research more of it on the net. Also, if you have a free class and go to the Academy of Art, I would highly recommend taking Jeremy Birn's lighting class. Or at the very least buy his Book on lighting. (Which is considered by many to be the standard for learning digital light set up.)

If you just want overall shadow control for fine tuneing, you can render out the images in "batches" and then bring them in to photoshop by compositing them all together. This way, you will have more control over your shadows.

[Joeythedolphin]

not sure what you're trying to do. If you want to create alpha from within Maya, you have to use procedural textures. Ramps, for example. Adjust the gradients as you like and plug it into a material's opacity.

[dabu]

for alphas, just select the verts you want to modify, and then select color -> apply color options and set alpha and color...