Regional weather and sky — 2026-09-16

Settings now expose WETTER / REGIONAL and AUS · WOLKEN BLEIBEN. The setting saves immediately with the rider profile. Existing profiles default to regional weather through the additive weatherDisabled=false field. BEWEGUNGSUNSCHÄRFE remains a separate switch, default off, using HDRP intensity 0.12 when enabled in a race.

Regional weather chooses a reproducible plan for each stage within a running session. Rain is most likely in Jungle, less frequent in China and Tuscany; the upper Alpine stage can snow; Egypt and Canyon can carry drifting dust. Clear sessions and long dry intervals remain possible. Showers fade in and out rather than appearing on every course. Weather OFF immediately stops emission, clears remaining particles, restores original road material property blocks and removes weather darkening/haze.

Moving HDRP CloudLayer clouds remain on clear days and with weather OFF. The single layer uses a square 256/512 map, four lighting steps and no cloud shadows or volumetric clouds. upperHemisphereOnly=false is deliberate: the installed HDRP 17.3 cache returns a released cloud texture under (height,height), so full-sphere square maps reuse their allocation instead of repeatedly missing the rectangular cache key at stage changes. The bundled HDRP cloud map is initialized through VolumeManager; isolated offscreen QA first renders two garage frames after assigning its target texture.

Tuscany stages 1 and 3 use native EarthSimple atmospheric skies for sunrise/sunset. The current dawn/dusk source uses a neutral white 90,000-lux solar source at 8°/6° elevation, exposure EV 11.1/10.9 and sky multiplier 2.5. Native atmospheric scattering supplies the low-angle warmth. Aerosol zenith opacity is 0.008/0.010, near the HDRP Earth default of 0.011928; these values are opacity, not generic fog density. Near-white horizon/cloud tints and a slightly violet zenith retain blue sky fill and readable foreground instead of applying an orange filter. Regional fog remains separate, with a 5,400 m mean free path for these two skies. Other regional daylight baselines remain in SceneLighting, including dry neutral Egyptian daylight.

Small native screen-space lens flares use one sample, no streak pass and intensity 0.065 (0.095 at Tuscany dawn/dusk); Performance quality disables them. Visibility depends on actual bright pixels and view direction, so an enabled component is not proof of a visible flare.

Rain, snow and dust use native camera-local ParticleSystems and transparent HDRP/Unlit materials. Only the selected kind emits. Maximum live particles at normal/high quality are 2,100 rain, 1,400 snow or 220 dust; Performance uses 900/650/100. An upward shelter check suppresses particles under roofs. Rain darkens and raises asphalt smoothness through renderer property blocks, which are restored when weather is disabled or the stage changes. Weather does not modify riding grip.

Native QA interface

RegionalWeather.SetQAOverride("rain" | "snow" | "dust" | "sunrise" | "sunset" | "clear" | "") is permitted only in isolated QA. It applies to the already loaded course and rebuilds its normal lighting profile. Empty resets the per-instance override. WarmupQA(camera, seconds) positions and simulates the actual production ParticleSystems while the gameplay clock is paused; it does not substitute an image or alternate effect.

Native audit can record ActiveWeather, Intensity, Wetness, CloudOpacity, CloudTextureAvailable, ParticleCount, WeatherEnabled, MotionBlurIntensity and LensFlareIntensity. Snapshot and restore profile fields around toggle checks. The shared shader retention list must include RegionalWeather.RepresentativeMaterials.

Implementation was checked against the installed HDRP package source (CloudLayer, PhysicallyBasedSky, ScreenSpaceLensFlare, HDRP/Unlit). The procedural soft particle footprint is created at runtime; shader-retention seeds use a serializable texture without replacing the runtime material's texture. Only position and UV streams are required for the selected unlit particle shaders.

Native visual and performance evidence belongs to the consolidated graphics audit for its recorded build hash. Earlier captures proved actual rain/snow particles and that weather OFF cleared particles/wetness while retaining clouds, but the first Tuscany dawn/dusk values were too dark; the corrected lighting above requires its own captures. This source-behavior document does not certify a final Windows build, photorealism or long-term GPU stability.