The state of Distance Field GI in 4.8

[anonymous_user_f2b8b290]

Do you think you can get the splotchy artifacts to a minimum for DFGI?

I can’t say with confidence yet. Some of the splotchy has been improved in my latest (not yet checked in) DFAO changes, which also affect DFGI. However, some of the splotchy is inherent to the technique. It remains to be seen. For sure the current level is unusable indoors though.

What is a good size for a streamed level? 50 square meters (Skyrim size), 1 kilometer?

It depends on what you want your streaming granularity to be. You can have a look at what we used for the Kite demo, that uses streaming for the interactive portion, distant areas are represented by a baked down mesh.

Is there any good way to transition to fully indoor scenes right now? Since everything is streamed we need to get rid of the skylight when entering but with a door and an animation that opens together with some clever camera cuts

If you use a Stationary skylight, it will be shadowed indoors and ‘just work’. This requires you to bake lighting though. Otherwise with a movable skylight you could just fade it out (ramp intensity toward 0) as the player is going indoors. When you look back outside it will look wrong.

what do you think would be the best setup for a scene like I described in my last post?

If you want a specific example, how about a primarily-outdoor fairly large jungle-y scene with man-made structures built in, that supports dynamic Time-of-Day?

I would go with heightfield GI (once it is considered usable) + DFAO on skylight. Indoors regions will have leaking though from the heightfield GI + DFAO shadowed skylight. It’s very difficult if not impossible to make a dynamic GI method that both performs well and does not leak =) Indoors can otherwise use local point and spot lights.