LuxCoreRender Forums

I encountered this bug because suddently, in an exterior scene, an asphalt material which uses a mix node + two disney nodes, was not receiving shadows correctly. Then i discovered that i was getting the correct brightness only by removing the mixed node.

using mixed single disney only

The attached scene is a simplified set-up of the same problem.
It's a closed box with an environnment outside.
the camera is inside the box.
To the base of the box i applied two mixed disney nodes. Each disney node has a bum map.
In theory, being the box sealed the resulting image should be completely black.

Instead, i get this:

if i keep one single disney node with the same bump applied the result is black as expected.
So it seems a mix+bump problem

Here the issue reproduced in blender :
In the blendfile you have 2 nodetrees.
one create the bug (bump in each of the shader being mixed )
and the second (bump in the mix node only) is fine.

the files : https://drive.google.com/file/d/1IP3dS_ ... sp=sharing

Hello.
Excuse me, but why highlight the asphalt at all?

hi, exactly this is the problem... it should be full black.

S0rda wrote: Wed Jan 26, 2022 11:02 am Hello.
Excuse me, but why highlight the asphalt at all?

It is a bug that let light pass throught object.
light come from the outside. object are solid
with no emissive material on them.

Add thickness to asphalt?

S0rda wrote: Wed Jan 26, 2022 5:17 pm Add thickness to asphalt?

It do not makes any difference. It's a reflection issue.

daros wrote: Tue Jan 25, 2022 10:38 am So it seems a mix+bump problem

The scene includes the definition of some very strange normal map:


used as a normal map:
This is wrong because the above image clearly not a normal map (i.e. it is a bump map). This is likely to be the source of your problem.

Normal maps have a very specific look, they looks like this:


where the R, G and B channels are used to encode the X, Y and Z offset.

Hi Dade, sorry for the long delay replaing you, i simply missed your answer despite thinking about it everyday,
If you look in depth to the scene you will notice that this normal map is not used. The texture with name 92411_1_sub1_normal01 is in fact not used by any material in the scene.

And for this reason Charles gets the same results i got, by setting up the scene in blender.
Did you revised Charles scene?
Thanks for you help dade.

Here is the blend Scene with no Normal map involved :

https://drive.google.com/file/d/1IP3dS_ ... sp=sharing