LuxCoreRender Forums

At the moment Glass opacity is larger than 0.0, means visible, deep blue appears above horizon line.
In my opinion this asks for explanation because I cannot see any physical explanation for this strong saturation of pale blue sky.

In general, mixing opacity with transparent materials is a bad idea, they are 2 contradicting properties: opacity literally makes the surface exists/not-exists (i.e. ray tracing can continue, ignoring the surface, it is like a glass with IOR 1.0). So it is like mixing two glasses with different IOR (something that doesn't makes very much sense).

About the specific scene, it is hard to be more specific without having the scene and all volume parameters, etc.

Dade wrote: Fri Sep 25, 2020 10:23 am In general, mixing opacity with transparent materials is a bad idea, they are 2 contradicting properties: opacity literally makes the surface exists/not-exists (i.e. ray tracing can continue, ignoring the surface, it is like a glass with IOR 1.0). So it is like mixing two glasses with different IOR (something that doesn't makes very much sense).

a|Glass material with opacity of 0.0 equals Null material as ever other material with opacity 0.0 does.
Opacity does not have any influence on Volumes but making them less (opacity >0.0) ore more (opacity <1.0) visible. It is only the material surface that renders invisible with opacity 0.0.

b|The opacity series I made to illustrate that there is something very odd with Glass material together with Sky's blue. Even stranger with Matte material reflecting (left box) or emitting (right box) Glass material looks rather correct (in contrast to the sky).

c|Believe it or not opacity of 0.99 for Glass materials can make much sense for some wanted or even from real world 'experiments' expected effects homo- or heterogeneous Volume. Although theoretically this should actually not be required. But I have the feeling Glass material does not behave as it should in certain circumstances even if the formulae implementations are are correct.

Dade wrote: Fri Sep 25, 2020 10:23 am About the specific scene, it is hard to be more specific without having the scene and all volume parameters, etc.

Sure. You can check the scene. Maybe I have done something unusual.



Blender Scene File Dade, I give you, and other developers you are working with on a team, temporarly the right to use scene and render results in the meaning of issue tracking / analyzing.

@All other persons following this post: Please, use this scene for personal use only.
I consider attached scene and its render results commonly protected by copyright laws, especial the main view with the transparent sphere in front of the orange boxes rendering an axial symmetric, rather flat looking object