Invisible Lights still visible Tweet

[dflamholc]

Hi
I'm having a slight problem with Octane Area Lights , where I have unchecked Visible to Camera and dialed down general visibility to zero.

THe lights still create a slightly visible dark triangle when visible to camera. This seems to be and issue only in a quite heavy scene with a lot of area lights (about 12 of them) and large areas with fine displacement.

I don't get the same error in a test scene with two area lights a sphere and a plane.

Any knowledge about this? Is this a known issue, or could there be something I can do to help it?

Any advice much appreciated

Thanks
David

[bepeg4d]

Hi David,
could you post some screenshots, to better visualize the issue?
Since you are talking about displacement, maybe worth to try to reduce the ray epsilon value
ciao beppe

[dflamholc]

Hi thanks for getting back

yes here is a few small screengrabs of the issue. Please let me know if this gives any hints.

I moved the Ray Epsilon to 0.005 a few weeks ago as I was having issues with banding in the displacement. that was just before the release of 3.06.
Im going to check now if that's the issue, but in case it isn't it would be good to know what could cause this.


Thanks
David

[bepeg4d]

Hi David,
thank you for screenshots.
Please, try with reducing the opacity at 0 in the Light tag, instead of using the Visibility options in Object tag.
ciao beppe

[dflamholc]

Hi Beppe
Thanks but yea sorry i tried that. That basically kills the whole light, including its rays.

.d

[dflamholc]

Ok so after completely dissecting the scene and deleting all C4D display tags, neutralising all light Octane light tags to standard settings and rendering on default Pathtracing settings the error still remained.
Nor did it have anything to do with the displacement.

It turns out that the shadow multipass bakes in the 'shadow' of the light although it has Visible to Camera OFF, as well as General Visibility set to 0.
Also this is not a true shadow of the area light, but rather a 'ghosting' or 'outline' effect of the light where it sits in space, rather than a shadow cast on a surface behind it.

The shadow multipass is not a necessity for me this time, as the compositors will be ok without it, but if this is indeed a bug, it would be nice if it could be looked at so we can use the pass in the future.

This error should be quite easy to replicate and let me know if its me that's crazy and doing something wrong here

Cheers
David

[aoktar]

Could you please post a sample scene? So we can understand better the issue.

[dflamholc]

Hi sorry this project is under NDA.
I will post a test scene showing the error once I get some time.

In the meantime, as I state above, the problem is solved once I uncheck the Shadow Multi Pass in the Beauty Passes under Octane Multipass tab

Best
David

[jooncult]

Same problem here in many different scenes. Lights are never really invisible. They leave a shadow trace.
Any ideas on how to fix that issue?
Best,
Ioannis.

[bepeg4d]

Hi jooncult,
please, try with the new 3.07 test version, there are important news for emission:
viewtopic.php?f=33&t=62395
ciao beppe