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Displacement bug: Produces emission if RGB map is used

Posted: Tue Jul 05, 2016 2:57 am
by Phil_RA
I have an issue if I use an RGB map in the displacement map (I tried grayscale map, same issue), whatever image I use as a texture will result in the material having a bright hotspot, as if the material was emissive. The material is a glossy mat, and has nothing but a displacement map. Switching to Diffuse shader doesn't fix it, only setting the displacement to 0 or turning off the daylight system fixes it.

Image

I removed everything I could from the scene until the bug would disappear. It seems I need the daylight system present and an enclosed space.

Win 10
Graphics card is Titan Black 10.18.13.6839
16GB
Nvidia driver 8.1.900.0
Plugin v3.02 - 4.2
3ds Max 2014 16.0

1- Open the scene
2- Open the material editor
3- Select the material named matbug
4- Go in the Displacement map
5- Go in the RGB image in the Texture entry
6- Assign any random image in there (can take a print screen of your desktop, save it, load it in there).
7- Go look at the small beam object in the scene, which has that material assigned. Notice it has a bright spot on it.

Re: Displacement bug: Produces emission if RGB map is used

Posted: Fri Jul 08, 2016 3:17 am
by Phil_RA
I see the file was downloaded a few times, anyone had the issue, or not?

Thanks

Re: Displacement bug: Produces emission if RGB map is used

Posted: Fri Jul 08, 2016 3:39 am
by azen
Thanks for the file. I will take a look into it now

Re: Displacement bug: Produces emission if RGB map is used

Posted: Sun Jul 10, 2016 12:36 am
by Phil_RA
Thanks!

Re: Displacement bug: Produces emission if RGB map is used

Posted: Mon Jul 11, 2016 2:41 am
by azen
Hi,

I have tested with other models made from scratch, and cannot duplicate the issue on here. The problem seems to stem more from the model itself. The issue is definitely specific to this particular model, rather than an issue that will consistently occur in other models with a similar construction. Is there any further details that you could provide, or other scenes with this issue occurring? It is important to know the extent of this issue before we can consider ways of resolving it on our end, if at all.

Re: Displacement bug: Produces emission if RGB map is used

Posted: Mon Jul 11, 2016 1:40 pm
by Phil_RA
Hello Azen,

Indeed for some reason it seems to only happen on this one. I don't see any particular issue with the model (it was made from a copy of other such models).

I should manage to create a new object and avoid the issue, but I reported it so you'd have a clear repro in case the issue is more widespread.

Thanks for looking into it!