What is the best way to make a mesh or texture partially invisible?
I want to make a sprite seem to be able to move smoothly between planes which are at different angles, and I guess the best method is making the part of the quad that is not touching the plane invisible, and adding a copy of it to the other plane.
Modify the alpha colour on the material associated with it - presuming you are using a shader (like a transparent diffuse) that allows this.
Example:
renderer.material.color = new Color(render.material.color.r,
renderer.material.color.g, renderer.material.color.b, alpha);
Where alpha is between 0 and 1
Do what mike says or you can use transparent shaders if you want good looks like in maya.
Hard surface shader this is a really good free source to go with.