I’ve attempted to follow along the video referenced in the documentation on Volumetric Fog and failed to reproduce it successfully under the Linux editor:
In the above picture, there is no light cone (god rays?) underneath the blue spot light (located in the left side of the scene), nor is there a light cone emanating from the far right rectangular object (located within a sphere collision outline).
Rebooting into Windows and running the Editor (using the Launcher provided binaries), with the same exact project, produced the wanted results straight away:
Is there any reason why this should be happening? I’ve already tried messing with various engine scalability settings, to no avail.
This behavior also occurs on 4.17 too (I’ve tried running the Editor with -vulkan under 4.17, it produced no difference).
I’ve the same problem with 4.18 on a GTX 1070 with Ubuntu 16.04 and Windows 10.
Even worse : If you save your project and try to open it on Linux BOOM see you lights ! Epic Fail. The spots are dead… Sorry for this bad pun, but Epic, we need help please !
I checked that in source code there is no support for volumetric fog when using OpenGL or Vulkan. It’s not implemented yet. On other thread I wrote a question about future support of it. No answers yet. When I tried to force generate volumetric fog using OpenGL Shader Compiler, there were a lot of strange colors related bugs. So we just have to wait.