Disney material Bug

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Sharlybg
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Disney material Bug

Post by Sharlybg »

Hi !

It seem the disney Material doesn't behave correctly with shadow and light.
Here image to show it.

File_Download_Blender 3.1
cassombra.blend
(1.15 MiB) Downloaded 86 times
First with 1 light bounce

Disney
1X1_Disney.jpg
Glossy
1X1_Glossy.jpg
matte
1X1_matte.jpg


Second with 8 light bounce

Disney
8X8_Disney.jpg
Glossy
8X8_Glossy.jpg
matte
8X8_Matte.jpg
Attachments
scenes_setup.jpg
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daros
Posts: 280
Joined: Thu Dec 12, 2019 3:25 pm
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Re: Disney material Bug

Post by daros »

I can confirm with this pther example:

rendered on november 2021 (sorry i don't know the exact release but monday i will research),
old.jpg


Rendered with latest relase
new.jpg
I also cannot upload this scene till monday
Luximage
Posts: 165
Joined: Sun Jan 14, 2018 8:01 pm

Re: Disney material Bug

Post by Luximage »

Yes same result here in cassombra scene with blender 3.1(blendluxcore 2.61) and blender 2.93(blendluxcore 2.6).
Maybe it is connected with what i mentioned in this thread: viewtopic.php?f=4&t=4350&p=33409#p33409
Since version 2.6 the disney material behaviour is different.
Changes made in 2.6 version according to Dade:
Disney glossiness evaluation (for PGI, Albedo AOV, etc.) now checks metal and specular parameters
Disney glossiness evaluation uses now the square root of the value to align with the roughness of Glossy2, Metal, etc.
Fixed a bug in Disney material causing bright edges.
bdjones
Posts: 7
Joined: Sun Feb 14, 2021 9:30 pm

Re: Disney material Bug

Post by bdjones »

Something to do with this?
MatteVsDisney2.jpg
The shadow terminator on the spheres is better in the disney sphere (right). The light degrades over a wider angle than the matte sphere, which has a too tight terminator and errors in poly's close to the shadow terminator. Because the matte sphere is plainly wrong (you can add a subdiv to the sphere and get rid of the bad poly raggedness but the shadow terminator is still too sharp, at least with any area to the light).
In the cassombra file the walls are close to edge on to the angle of the sun so the light brightness on the wall should be less, yes? (compared with the light on the near perpendicular to the light floor). It just seems like it's related.
kintuX
Posts: 809
Joined: Wed Jan 10, 2018 2:37 am

Re: Disney material Bug

Post by kintuX »

I personally don't think it's related to 'terminator', but indeed has some relation to shadows/light falloff value. Since very beginning of LuxCore I'm observing less contrast then in other engines and usually tone mapping fixes things (also in this case) but I have never done a proper comparative study.

quick e.g.
Cycles principled BSDF
cassombra.cycles320.jpg

Corona Physical
cassombra_corona.jpg

LuxCore (tonemapped)
cassombra_luxcore-TM.jpg
PS
IDK, I just know I never achieved Corona's OoB lighting w/o tinkering with light settings & tonemapping

-------------------------------------------
PPS
Clamping helps calm effect down.
cassombraX _(LC2.6-Clamped&CameraSunGain1).jpg
Attachments
cassombraX.blend
(1.01 MiB) Downloaded 86 times
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