Hi,
I am trying to produce an alpha channel of shadows only or a pass with only my shadows!, I am quite new to VRAY so A bit of an explanation would be appreciated if it is at all possible.
Many thanks in advance.
you may approach it in few ways:
1 - apply single vray material wrapper to the entire scene, and specify to render only shadows, if you set alpha contribution -1 the returned result in alpha will be shadows only.
2 - you can apply a single vray material to the entire scene, take all your lights, set their intensity to 0.001 and shadow color to full white, this will also return shadow only in render.
3 - you may play around with render elements shadow passes, they also generate shadows, but often we use custom shadow passes created with methods above.
I can not seam to get this working… I wish to render just the shadows with an alpha for easy compositing.
I have tried both methods.
Could you please explain in more detail…
I have a simple scene illuminated with a single light and a GI LC on both bounces.
If i click OFF “use global settings” in the lights “shadows” drop down thing… i get this… but it looks wrong?
This is the method as i understand it from your description using the lights at .001 etc etc
This is the method using the vrayMltWrapper method as i understood it from your description.
As you can see neither is rendering just the shadows on the render.. and neither is showing just teh shadows on the alpha map.
I am using rc2 and max2009
Any help would be appreciated.
is the alpha contribution of the matte set to 0 or -1?
In the VrayMtlWrapper, uncheck ‘No GI on other mattes’ - that made it work for me.