alpha channel

[dalsayegh]

Hi,

I am rendering an image that has a skydome as the sky with a texture map on it. I would like to know how to save the rendering with an alpha channel of the sky.

Thanks for your help,
Dalia

[travistlo]

Is the skydome an object, or max enviroment?

If max enviorment skip to ***

If it is an object, (a hemispehere or whatever) i would erase it. If the rendering takes a long time do the following: Make all the materials a simple color, doesnt matter turn off reflections, refractions, maps, etc. (just to speed up rendering)

Render the scene again

***Save it as a tiff with alpha map.

Then in image editing software, you will have a alpha channel that you can use of just the sky.

Hope this is what you ment, I will bet somone knows another way, this is what I would do.

[egz]

Hi,

Select your skydome, right click, select VRay Properties from the lower right quad menu. In the VRay Properties dialogue set alpha contribution to -1. Do not turn on matte object.

When you render now, your skydome will be transparent in the alpha channel.

[dalsayegh]

Thanks for the answer. It worked.

Dalia

[TRGraphics]

egz,

That was a damn good tip, thanks for sharing! That was just what I needed for a scene I'm working on.

Tony