Possibly because the material the Skydome uses is not set to allow VXGI emittance. Find the material and open it up and take a look on the left side (can’t remember the exact option name). Report back and let me know if the option is ticked or not. In the mean time I’ll do some testing here.
EDIT: Yeah the option is unticked. “Used with Vxgi Voxelization” needs to be ticked in M_Sky_Panning_Clouds_2
Just doing some testing here, even tho the option is ticked, the SkyDome is just too far away. It will never be involved in the voxelization and therefore will not emit. Your best bet is to set the Environment Map option in the VXGI Diffuse/Specular section of the Post Processing volume to match the skydome and change it for day/night time.
Or use the skylight. Make sure VXGI indirect lighting is set to true on the Skylight
I would like to know if it is possible to do a day/night cycle with the VXGI branch of UE 4.12 . I am able to get indirect lighting from my directional light but not the sky sphere. I thought VXGI supported unlit materials so it is unclear to me why a basic unlit material seems to emit indirect bounce from VXGI but not the sky sphere material (since it is also an unlit material type).
Good to know and that is a shame that it’s not compatible. Using the skylight is not ideal since i’d just end up doing the blueprint i’d be using without vxgi anyways. I was hoping vxgi could save me the time of having to set that up…I assume there is no way to bring the skydome closer? Couldn’t I just rescale the sky sphere mesh?
Bummer, well thanks for testing it out
Not really, I tried that, it has to be pretty close to be involved in the voxelization, the only two choices are Environment Map in the VXGI Post Processing options or a skylight.