Ambient Occlusion in compositing removes HDR lights :/

Guys, can anyone help me out in this?

If I set AO in compositing my HDR image goes black, depending AO factor. Is there any trick to leave HDR image alone and affect only objects?

This is before:

And this is after Fac is 1

Note that more there is Fac value, more it affects HDR.

connect alpha to Fac

Nothing changed :confused:

This multiply Fac value controls how much AO is multiplied

Oh, Alpha dont take in account environment, weird.

So just use depth buffer to get alpha mask of all objects

Also, you could enable the environment pass and use it instead. I think it would be a bit better since it’s antialiased and has transparency

Nice approach, have to dig how it’s done but anyway, got some artifacts, AA thing… Also, how can I control Multiply value?

image

Andrew, can you point exactly where Env should go? I have rendered new image with Env pass enabled.

Is this done right?

I think Alpha channel doesn’t look great :frowning:

image

Yeah, I don’t think that will work, try something like this:

The antialiasing node helps to smooth the edges, but it’s quite slow, so you might only want to use it for a final render rather than while working on it.

Guys, thank you for your help!