I tried rendering a scene with a cube with a volume shader lit from within by a point light. Version 3.6.5 renders the scene with no problems. Version 4.0.0 Beta renders the same scene with a visible disk the actual diameter of the point light. I don’t think this is right, but I don’t know if it’s a bug. Thanks
Here’s V 3.6.5
I’m not sure about 3.6 I dumped it just today, for 4.1
But 4.xx looks correct or at least better. 3.65 looks like it is not working as it should…
Just think about lights in a thick fog or passing through clouds…
Photo
Thanks for the response. There’s definitely a difference between the two versions. I think Version 4.1 is modeling lights in a volume in a way that’s more physically accurate. Anyway, I found that I could achieve a similar look with the new version. I did this by setting the point light radius to about zero and moving the light behind the volume rather than inside it. This smeared the illumination in the volume.
Yes, it is far better to “Hide” the lighting within the Volume…and like you said set with a radius of zero works also…unless you want a focal point…increasing the radius adds some fine effects also…
Reminds me of this thread.
But that was spot lights.
Lights have been reworked in 4.0
Yes it is related.
Here I have a floor, a ceiling and 2 lights a white point and a red spot.
Note that the ceiling and the volume are totally lighted inside the lights radius.
The same file in 3.6
There is no “radius lighting”
The 4.0 one is agx and the 3.6 filmic but that is not the point.
Here is the 4.0 one in filmic for those who like to compare that.
Note that the point lamp on the left has White light, (or should be).
I think that the radius lighting is also acting on surfaces (even with no volume present). One slightly bad thing is not getting the same results with some files made with the previous version.
Yes it is acting on surfaces (look at the ceiling plane), it has to do with this change, (from release notes)
Point light and spot light are changed to double-sided sphere lights (#108506 #109329). Besides, the light normal now points from light center to the sampled/intersected position on the sphere, any pipeline that was using the light normal should use the Incoming socket of the Geometry shader node instead.
I have not found a good way around it. You can clip the "“in radius” like this, the “less than” value has to be twice the light radius to get rid of the inner light.
This is not ideal as you can see, especially for volumes.
