Interface DaylightAnalysisParams

Number of evenly-spaced sample days through the year. Default 12 — one per month. Increase for finer time resolution at the cost of linear runtime growth. 52 (weekly) or 365 (daily) are reasonable next steps.

Rectangular work-plane sample grid.

Number of evenly-spaced sample hours through each evaluated day. Default 24 — hourly. Drop to 12 to halve the time cost.

Sun altitudes below this threshold (degrees) are skipped — the sun's contribution is negligible at horizon angles, and the raycast against the BVH would dominate runtime without changing the answer. Default 5°.

Scene whose objects act as occluders.

Diffuse-sky model layered on top of the direct-sun raycast. When non-"none", each cell additionally fires skySamples cosine- weighted rays into the upper hemisphere to estimate its Sky View Factor under the chosen luminance model, then combines that with the direct-sun term to produce an annual horizontal illuminance proxy (in klux·hours) on the result.

• "none" (default) — direct-sun only. result.unit stays "hours" and result.values holds annual sunlit hours, matching the previous behaviour exactly.
• "cie-overcast" — CIE Standard Overcast Sky (CIE 1955). Brighter at zenith, dimmer at horizon — the canonical daylight-factor sky and the basis of UK BRE 209 / EN 17037 calculations.
• "uniform" — Uniform sky luminance (CIE 1). Simpler, useful as a baseline for "any sky at all" view-factor work.

Sky modelling roughly doubles runtime (skySamples extra rays per cell on top of the existing time-step sweep).

Number of cosine-weighted hemisphere samples per cell when skyModel is non-"none". Default 64 — enough Hammersley stratification for a smooth SVF estimate at typical grid resolutions; bump to 128/256 for noise-free output at the cost of linear runtime growth.

SunStudy providing the site location (latitude / longitude / northAngleDegrees). The analysis ignores the SunStudy's currentDate — it walks its own time samples independently — but reuses the site coordinates and north angle.

Year to evaluate. Defaults to the current calendar year.

How many ms an await yieldToHost() pause needs to honor. The analysis runner yields periodically so the browser stays responsive during the long raycast sweep. Default 16 (60 Hz).