real alpha in mental ray?

[Jozvex]

Well, in the example image I've attached, I rendered the scene once with all Surface Shaders (set to the colour I wanted), then rendered again with all the objects given the same lambert shader.

The lambert has full white as the colour and a diffuse of 1. This 'lambertised' scene was rendered with Final Gathering. The environment colour is set to white to make the whole thing more alpha channel-esque and I had to turn down the lambert shaders Irradience Colour to a white value of only 0.3 to compensate for the bright environment.

Then in Photoshop I just layered the images and set the 'FG channel' image to Multply!

Any help?

[sebast1an2]

hm.. fg channel? multiply? do you have "keyed out" the white color?

of certain you will explain this to me, but thats not really the solution that i've hoped... is there no "real way" to get the original shadows & reflections like the use background shader??? how did the xsi users that?

greets:shrug:

[Jozvex]

Originally posted by sebast1an2
hm.. fg channel? multiply? do you have "keyed out" the white color?

I've attached another image to explain what I mean. When I said "fg channel" I just meant the greyscale layer that was rendered with the lambert shaders. I've put a green dot next to it in the attached image.

The red dot in the image shows what I meant by "multiply", it's the way I've added the layer in photoshop. It multiplies the colours together.

The blue dot in the image shows the layer with the Surface Shader render.

Originally posted by sebast1an2
is there no "real way" to get the original shadows & reflections like the use background shader??? how did the xsi users that?


The Use Background shader should work fine, but no it won't collect the Final Gather shadows, only normal ones from lights. XSI users can do it because their Mental Ray is more built-in than ours is.

Maya will get there eventually!

[CGTalk Moderation]

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.