AO affects shadows on a matte material..

Support Compositing and Post Processing
1

I have a object composited over some footage with a transparent plane underneath that receives shadows.

If I do a basic render the shadow is nice and strong, no problems.

But I have noticed that if I turn on AO and render then the shadow on the transparent plane either fades out or disappears altogether.

Is there any way around this?

Thanks in advance,

Tupik :slight_smile:

2

AO simulates totally ambient lighting where there is no light coming from any specific direction, so it makes sense that it would “fight” shadows. AO is a dirt shader that darkens creases to kinda simulate shadows (actually more like a lack of radiosity and spec from angled light into corners) - but not shadows. You should either bake AO, or make two render passes - one with shadow and the other with AO, and then composite them however you want to get the effect you want.Another option would be to use AO "Sub"tract.

3

Fantastic. Thank you so much for clearing that up for me.