render lights only with alpha channel and post processing

[Philipp1980]

Hey everyone,

I have the following problem:

I made a rendering, where some of my ceiling light spots weren't strong enough to be affected by the post processing glare effect. So I tried to render the spots only (with alpha channel) and applied the post processing effect to combine the image with my original rendering in photoshop. But when saving the image as png the post processing effects are lost (you can see them in the attached jpg image).

Is there a way to render and save the lights only with alpha channel while keeping the post processing effect?

And if there is no such way, does anyone know a way to create a similar effect in photoshop (good plugin maybe)? The standard filters aren't that good I think.

Best regards to everyone

[stratified]

Hi,

You can render the post effect separately with the render passes. The only thing you have to do is enable the post processing render pass. I created my example in the standalone but you can do the same thing with the Max plugin. You can combine both passes with the add operation in ps.

Beauty pass without post-effects (this pass has alpha enabled).

Post-effects only.

I hope this helps.

cheers,
Thomas

[caffe3]

A photoshop plugin that can do all that (not sure how well compared to Octane, but it should be more than decent) plus way more:
http://software.tiffen.com/products/dfx ... to-plug-in

[Philipp1980]

Hey guys,

thank you both for your answers! Sorry for the delay of my answer, I had a lot of trouble to do here with that order

I will try your solution right away

[huey_yeng]

IF you need a precise selection of the light sources as a separate pass, the Emitters pass from the Render Elements is handy too as it only render any object that cast light in the scene.

I use it a lot when I composite in Nuke as it allows me to track in a lens flare with the Emitters pass and comp it over the beauty pass.