Great work on the new lightmass! I’ve waited so long for a successor to the existing one.
After playing with it for a while last night there are a few items I’d like to add to my own wish list - obviously @Luoshuang and Epic have their own plans for this, but I can only dream.
- Top of the list is the ability to bake individual static lights to their own lightmaps (or referenced maps) and have those be adjustable after bake. This would be the killer option for any future pre-baked solution for me. This would mean that the pre-baked bounced lightmap of static lights could be faded up or down via blueprint / script. This would allow day and night scenes to be baked for each map (UE level) and then fade them up as the sun rises. Failing that, just having a more simple ‘channel’ system that allowed you to assign sets of lights to a bake channel, then that channel could be faded up and down at runtime.
- Proximity aware baking - this probably has a better name, but it would mean that, if you have a large level that you’ve already baked most of the light for, and you want to adjust a small light somewhere within the level, then lightmass would only rebake the objects that are effected by the change - rather than the entire level over again. Failing that it would great to have the ability to lock lightmaps for objects once baked, so they’re ignored in future bakes. Huge time saver either way.
- Ability to draw volumetric light density boxes (also exposed in construction blueprints) - the fully automatic system at the moment is useless at optimizing itself for complex meshes (which makes matching the light conditions of static and movable meshes very difficult). If we could draw volumes that dictate volumetric probe density around any object we’d like then that would solve those cases. It’s great to see that new GPULightmass works with the current volumetric light probes, but the current light probe system is pretty useless and doesn’t allow much granular control (plus it can only populate cubic areas, so it produces loads of wasted light data in the air above geometry!). Unigine and Unity have versions of this functionality, please consider adding this if you can.
- Multi-GPU support - big must, but I expect it is already in the works. Multi GPU on local machine and multi GPU networked machines too. Crazy not to have this.
Big asks I know, but what a difference they would make. I’d really love any news on these.
Here’s some other things I noticed whilst playing around - which I assume the devs already know, but I’ll put them down anyway.
- Light Intensity for skylights and Indirect light intensity for all lights do not seem to have any effect right now, lights all seem to be stuck on their default intensities.
- Directional Light Source Angle not working - would love to see this working, at the moment only pin-sharp sunlight supported, no ability to mimic overcast conditions.
- Toggling ‘Lower Hemisphere is solid color’ seems to have a dramatic effect on the accuracy of skylights, they go from blinding in all directions when on, to accurate when toggled off.
Anyway, I’m done being annoying and entitled. Really great to see progress being made on this and can’t wait to see where it goes!