Object "ghosting through"

[Art48]

Hi,

I got a super simple scene, a groundplane with a screw lying there.
It all looks great except one thing: There is a nasty shadow of some kind in the lower right half of the image, see image attached.


Scene file is uploading to my FTP as I write this, will provide a link to support@chaosgroup.com when it's finished.

I went through the usual object/Vrayproperties already and can't find an error there, also the GI pass is completely black in the problematic area.

[Art48]

Just sent the mail to support containing a scene file

[Joelaff]

Overlapping pollys on the floor?

Shadow bias needs adjustment?

Some kind of environment set to Screen projection?

Try looking at render channels to see where it is (GI, reflection, lighting). Turn lights/GI on and off to narrow it down.

[Art48]

Good tips - I think overlapping polys I went over already, but will doublecheck - also good tip on the shadow bias, will check it tomorrow and report back.

[svetlozar.draganov]

Have you received a reply from the Support Team?
If not would you please let me know the ticket number you've received so I could check the scene?

[Art48]

Hi,

Ticket is #143234

[Joelaff]

Did you ever figure this out? I'd be interested in seeing a test scene. Does the issue happen without the hero bolt object? Could you maybe post a simplified scene without any valuable assets?

[Art48]

Didn't have time yet, MAYBE today, but not sure...

[svetlozar.draganov]

Hi,

Ticket is #143234

Thanks for the ticket number. You should have a reply in your mailbox from my colleague Miroslav which states the following:

The strange shadow you were seeing on the bottom right corner is actually the reflection of the "Problematic_Object" mesh traced on the ground plane ("Boden_Highend"). You have the "Visible to camera" option turned off in the object properties so the mesh isn't rendered, but is still considered for reflections/refractions. Just turn off "Visible to reflections" in the V-Ray object properties dialog or "Visible to Reflection/Refraction" in the native 3ds Max Object properties dialog.

[Art48]

Interesting: What is the default value of the secondary ray bias? Mine was set to 0.0.

When changing it to 0.01 things got better but were not gone.
0.02 made it go away completely.

As stated by support the problem was the reflection of the object in the floor itself - dumb, could've thought of that.
Anyways I guess it's about setting up trace sets then.

Interestingly enough tin this specific case the workaround with ray bias works ^^