I really like lightmass and its quality but i am trying to do some day/night cycle using only a stationary skylight with a movable directional light for the sun and the results are ok…
I think if will be possible in the future to bake multiple lightmass settings (one for day, another for the night) and blend then over the time. This would be perfect for a day/night cycle. I dont want any full dynamic global ilumination because i think they kill the performance and the final quality its far away from lightmass. I want to know from someone from lightmass team if there any plans to implement this feature on lightmass. If not, there is a workaround for me to do this?
It would be nice to have, though that would not be good for your situation–blending between them would not look like a day/night cycle, the shadows and colors would be very wrong. Also, if it had both lighting builds it would have to load both in the memory which would be a massive performance hit.
I still think it would be nice though for cases where you have a big map that you want different lighting situations without making a new copy of the map.
If can i bake the light from skylight on day and on night and blend them for the ambient oclusion variation and global illumination i think the result will be better than now. Because now i bake the light from sky light on day and using blueprint i move my sun light, the shadows look very good but the ambient occlusion and gi are the same, i am trying to change the ambient light and indirect light intensity with blueprints base on my sun position but i cant figured it out. i want to make my scene darker when the sun disapear. I am using the default skybox that have the sun and the moon.
Still, you wouldn’t get good results, it would look very funky to try and blend lighting from the daytime to the night and the performance issues would be very bad
In the world settings, you can actually see and change/fiddle with the lightmaps.
So it should be possible to change them by code?
Just guessing here. My c++ is still noob level…
You could do it if you had multiple samples, say every 3 or 4 hours, although at this point the storage costs would be pretty damned high. (Performance however wouldn’t be that bad, you’d just require two light textures instead of one and a lerp between them - bit of extra bandwidth, couple of extra instructions).
Having double the amount of lightmaps wouldn’t work very well at all. And blending would end up with multiple shadows, it’s not like the shadows would morph together.
But it could work for instant time jumps.
For example, its night and the character “uses” a bed in the game. And poof! its some hours later and during day.
A bit like “sleeping” in Fallout 3.
Of course one could duplicate the map and bake a lightmap for each, but that would have to be repeated after each change…
But true, blending makes only sense in some edge case scenarios…
Right, having a set of lightmaps for a level that’s being used for different times of day would be great, but trying to use it for something dynamic wouldn’t work
It would only work on days that are overcast with no hard shadows 