I am trying to do a fully dynamic night/day cycle using VXGI. However I seem to be unable to get any sort of global illumination lighting from the sky sphere. I would assume that this is support because it is an unlit material and I seem to have no problem getting diffuse gi from other unlit materials i create so I am not sure why the same doesn’t seem to apply for the sky sphere.
I am having trouble finding any information on doing a day/night cycle with VXGI so any help or pointers would be appreciated
got my question answered on answerhub. Seems like its not supported because the sky sphere is too far away : /
If anyone has tried doing a daynight cycle with vxgi, I’d love to hear their process.
The things don’t work like that, you have to setup the light with a directional light or skylight or other light and then rotate it and do some magic tricks, the sphere of the skybox don’t affect in nothing, probably in the ambient secondary light but nothing more.
Not sure how works in VXGI but should have a main light that you can control.
I’ll answer here for others to see (I already answered on the Answerhub as Iromm is aware):
Well VXGI can actually light from emissive sources, the issue with using the SkySphere as a light source is VXGI only has a limited range and the SkySphere is just too far away. It would have to be scaled incredibly close to be able to use. Its better to use a Skylight (Enabling VXGI indirect lighting) or set an Environment map in the Post Process VXGI options.
Use a movable (or stationary if you aren’t using VXGI) skylight with a color curve that matches up with your sky’s color over the entire day/night cycle. Generally works pretty well.
Thanks for the replies. I think what I’d like to do is capture a couple of cubemaps for the skylight and have them blend from one to another in a way that is synced up with the rotation of the directional light source. I’ve figured out how to set up the cubemap blending through this tutorial:https://www.youtube.com/watch?v=cHzt73Tn0L4
but I am not quite sure how to set them up in a way so that each cubemap blends in sync with the time of day. My directional light is using a timeline of 24 seconds to cycle through a day so ideally id have some way to blend my 12pm cubemap at 12second, my 5pm cubemap at 17 seconds and so on…I’m assuming with a cubemap you get more variety in the ambient lighting rather than using a single color because it is looking at the hdr cubemap for its indirect lighting, unless this is not the case?
actually now that i think about it, when i use a cubemap- that is basically defeating the purpose of vxgi isnt it? since it is taking lighting from a precomputed source rather than having the color of the actual skylight change in real time?..that being said it would be interesting set up vxgi to use its own environment but how i would have the vxgi environment maps switch from one to another and blend is unclear.