Render unpremultiplied render passes with Alpha ? Tweet

[fantome]

Hi guys,

I would have two question about render passes :
1) Is it possible to render the beauty render passes ( like emission / diffusion / reflection / refraction ) without being premultiplied by the alpha of the object , in order to get the raw pixel in the edge of the alpha to avoid black line in comp ?
2) Is it possible to ouput directly an alpha channel of the render elements in each render passes or do i have to rebuild it on comp ?

My goal is to be able to recompose an image in comp with refractive / reflective object by using only render passes.

It does work with render layer but it is longer to render i would like to know if i can get the same thing only with render passes.

Thanks for your lights
Cheers
E

[juanjgon]

Hi,

Have you tried the "Pre-multiplied alpha" option available in the render target "Imager" node/tab? This option should affect all the passes, as far as I know.

Thanks,
-Juanjo

[fantome]

Thanks for your help Juanjo !

I have already play with this one but i will double check this option and tell you if it solve what i am searching for.

Cheers
E