Sunlight built from the grid

Standalone headsets do not get a volumetric fog pass, a depth read or a compositor stage in the budget I have. So instead of faking light rays with a post effect, I read them off the voxel grid, the same way meshes and collision come from it.

Four layers

1. Sun shadows. One directional light, crisp filtering to match the flat look, only the nearest opaque terrain casts. I had to raise the sun against ambient before shadows read at all; the old balance left shadowed ground nearly as bright as lit ground after tonemapping.
2. Sky exposure. The mesher writes how open each corner is to the sky into the vertex colour. Under a roof, a canopy or a cave ceiling the ambient drops, while direct sun through a window stays bright. A hut floor is dark all the way to the door because merged quads never cross a cover boundary.
3. Sun rays. The native core finds covered air cells whose line to the sun reaches open sky through an aperture: a window, a doorway, a skylight, a cave mouth. Adjacent openings merge into one rectangle before the beam is extruded along the sun, so a long window gives one clean shaft instead of a comb of thin ones.
4. The day. Sun height, colour and the shafts move together over a day cycle, into a night with stable stars and fixture lights that cast their own shadows.

Why this matters for a building game

You will build with your hands, and light through the thing you built is half the reward. A window you cut yourself should throw a beam across the floor. Now it does, on the grid, at a cost I can afford on Quest 3.

The shot above is from the teaser: those shafts on the ridge are the same beams, found where the sun reaches through a gap in the terrain. At night the same fixtures and fires light a room through their own shadows.