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Light passes don't premult correctly

Posted: Mon May 27, 2019 6:47 pm
by ptunstall
Hey so lighting passes don't premult correctly in compositing. I've linked the HIP file and render below.

SCENE: https://www.dropbox.com/s/lf4w14gpl95jl ... e.zip?dl=0
EXR: https://www.dropbox.com/s/iyfqmgrvfhml5 ... 1.exr?dl=0

Re: Light passes don't premult correctly

Posted: Mon May 27, 2019 8:17 pm
by juanjgon
Hi,

What problem do you have exactly with the light passes? According to the docs, they must be added together to recreate the original render in post.
https://docs.otoy.com/StandaloneH_STA/S ... Passes.htm

Thanks,
-Juanjo

Re: Light passes don't premult correctly

Posted: Mon May 27, 2019 8:57 pm
by ptunstall
Yes traditionally adding them back together has worked. If you were to checkout the exr linked you'll see that doing this reveals an illuminated edge akin to unpremutliplied renders. Even if I premilt them again the edge still shows up.

Re: Light passes don't premult correctly

Posted: Mon May 27, 2019 9:39 pm
by juanjgon
So, did this feature work fine before? Do you know the latest Octane version where it was working fine?

Thanks,
-Juanjo

Re: Light passes don't premult correctly

Posted: Mon May 27, 2019 11:35 pm
by ptunstall
Yes we've used this feature a lot in 4. I haven't used it much since moving to 2018.

Re: Light passes don't premult correctly

Posted: Wed May 29, 2019 9:18 pm
by juanjgon
Sorry, can you please send us the .orbx file from the scene used to render these to light passes? I've been trying to reproduce the problem using your Houdini scene, but somehow I can't get this kind of lighting, so I'm not sure if I can see the same problem here.

Thanks for your help!
-Juanjo

Re: Light passes don't premult correctly

Posted: Fri May 31, 2019 3:27 am
by ptunstall
sorry for delay:

https://www.dropbox.com/s/0oj5pfpbqheld ... .orbx?dl=0

You can see the issue easily in standalone. Just select ln1 or ln2 in the viewpoint.

I'm using multiple rops and also layers maybe it's something to do with layers?

Re: Light passes don't premult correctly

Posted: Wed Jun 05, 2019 2:07 pm
by ptunstall
Any info on this?

Re: Light passes don't premult correctly

Posted: Wed Jun 05, 2019 2:21 pm
by juanjgon
Hope, sorry, not yet. I've sent the scene to the core devs to check it, but I have no news yet.

Thanks,
-Juanjo