storm_sheet

Additive upright sheet of slanted rain streaks in patchy gust bands, turned to face the camera about the vertical (zero_billboard_axis with world Y). Dozens of them sweep across the scene on the wind, which makes the rain read as weather. On each sheet three layers of fine lines run along a wind-slanted fall direction; every line has its own length and phase and falls with time, so they read as individual drops. A value-noise gust pattern, drifting with time, makes the sheet thick in gusts and threadbare between them. The sheet fades in and out over its life and toward its edges. The streaks are a cool blue (0.46, 0.56, 0.78) lifted by ambient + flash * flash_gain, scaled by density and faded with distance by exp(-distance * fog).

The storm graph (storm/storm.procGraph) draws its sheets output with it (additive, flash from the storm schedule's flash expression, flash_gain 0.9, ambient 0.16, fog 0.005, and density animated as 0.55 + 0.25 * sin(t * 0.9) + 0.14 * sin(t * 2.3 + 1.7)): up to 90 sheets 46 to 92 wide, born on a wide disc upwind and carried across on the gusts for 7.5 to 9.5 s each. The graph writes data0 as (life, a random seed, 0, 0). In the Procgen Effects Showcase world, the fx_storm scene plays the graph.

The shader includes @builtin::shaderModules.billboard.

Properties

Lanes