WebGPU Shadow Accumulation Lab

Sun & accumulation period

Latitude Longitude

Coordinates move the sun, not the ground or buildings. North is −Z; east is +X.

Start date · UTC End date · UTC

Sampling interval 15 min

Both dates are included. Samples are evaluated at interval midpoints. Night-time samples are skipped.

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Heatmap

Measurement Color scale

0%100%

Received / possible direct energy at the same surface orientation. Gray means no front-side solar potential.

Show accumulated heatmap Heatmap opacity 100%

Generate to see area-weighted results.

Resolution & engine settings

Surface atlas Shadow map

Sun samples per GPU batch Constant direct-normal irradiance 1000 W/m²

Idealized constant beam × incidence cosine × visible time. This is not weather-calibrated solar yield; diffuse sky and reflections are excluded.

Surface offset 0.020 m

Lower for thin obstructions; increase only for self-shadow acne. Receiver-plane depth correction is already enabled. No PCF blur in the integration.

An analytic four-point test for this device. No scene changes.

One reused shadow texture · f32 storage-buffer totals · GPU reductions · GPU-only color atlas.

Preview sun & camera

Preview date · UTC Preview time 16:00 UTC

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The sky and live shadows follow this preview. Changing it does not alter an accumulated heatmap.

NESW

0°