Occlusion Preprocessing slow-ow-ow

Hi guys,

Suddenly my render times increased a lot - it takes a long long time in a step called “Occlusion Preprocessing”. I don’t know what I did to “turn this on”, I’m pretty sure the scene I’m working on used to render much faster. I can only associate this with Ambient Occlusion but it is turned off, so…

I’m using a more or less recent build from graphicall, 35739 with bundled luxrender, but I tried falling back to the official 2.56a (in which I started the scene) and had the same problem. Windows7 64bit.

Any ideas?

You have environmental lighting turned on.
It basically is just another occlusion pass that brightens the scene instead of the darkening of the occlusion.

Both need Occlusion Preprocessing :wink:

Indeed I do, thanks arexma. Then I’d say it’s probably the environmental lighting + SSS that suddenly slowed things down (EL was there before but SSS just recently). Guess I’ll have to live with it!

Or was it? As soon as I made the hair material for my character NOT cast shadows, times are back to normal. Makes sense, calculating shadows for 37500 hairs must be somewhat time consuming :slight_smile: Solved!