rendering black!

[cdavis]

Hi,

When I render an image , for example a car , which I render on black to be comped in, in another package It seems to take forever to render the black part of the image. I am working at 10k pixels so pretty high res & I understand the actual car geometry taking a while ( which it doesnt usually its pretty quick) but It seems to take as long rendering the black in the background.

Is there a way to stop this or is this normal?

Thanks

Chris

[Yannick]

Hi Chris,
Usually it render a lot faster then the actual geometry, if the environment is set to black.

[cdavis]

i have a environment light , which is set to invisible but its definatly not rendering fast. OK, so its not taking ages but I would expect it to take a split second , am i wrong? as it takes about 30-40 seconds per bucket on the black section

[Yannick]

do you have some high samples? I guess that could slow down the render even if invisible.

[cdavis]

i use the adaptive DMC & use the subdivision multiplier set to 10, which is what I usually use.

[aweidenhammer]

yes, but what is your min subdivs? That is usually the issue with taking too long on blank areas. min of 2 or more is like fixed of 2 or more on those areas. Set it to 1 and it should speed up. If that's not it, I'm not sure

[cdavis]

min is set at 1. so ... no not sure why then.

[vlado]

Do you have any render elements? What is your AA filter set to?

Best regards,
Vlado