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the-eandClaude Opus 5
5e745f7535
Raytraced shadow penumbras needed a hand-authored $SunAngularSize: in stars.tbl, which no shipped content sets -- so in practice nothing ever got a penumbra, and the shadow-mapped path's $Shadow Smoothness Factor: had no relation to it at all. Derive a size from the sun bitmap instead and drive both methods from the same number. g3_render_rect_screen_aligned_2d() sizes the sun quad so its rad is the tangent of the half-angle it subtends, making tan(angular radius) equal to 0.05 * the mission's +Scale: * the emitting disc's fraction of the bitmap. That fraction is the area of the pixels at or above 90% of the brightest one, converted to an equivalent radius. Across 90 sun bitmaps from retail, the MediaVPs, Blue Planet and BtA it lands at a median of 0.261 (retail's chunkier art at 0.487), and the threshold acts as a constant factor rather than a per-bitmap judgement call -- Spearman rho 0.96 between a 90% and a 50% cutoff. Taken literally that yields suns 3.9-8.5x Sol's apparent diameter once +Scale: is folded in (median 1.55, up to 5.0 in retail's own missions), so the measurement is scaled by 0.25 and clamped to 1.5 degrees, putting typical content near Sol. Derivation is the default: $SunAngularSize: 0 asks for hard shadows, an explicit value still wins, and missions can also set +AngularSize: on an individual sun to override both, with FRED and QtFRED UI (validation and fallback included) to author it. Bitmaps that can't be read -- and the deliberately blank sun bitmaps mods ship to get a light source with no visible disc -- fall back to hard shadows rather than to the widest possible penumbra. That angular size now sizes the raytraced penumbra cone directly (traceShadowRayCone() in shadows.sdr), with sample count following the same Shadow_quality tier that picks the shadow map's resolution (1 ray at Low, up to 16 at Ultra) rather than being a separate setting. The shadow-mapped path's tabled smoothness values were tuned by eye against Sol-sized retail/MediaVPs art, so shadow_smoothness_scale() in shadows.cpp scales them by the active sun's size relative to Sol, clamped to what the shadow map can represent (shadow_clamp_smoothness()). The two methods still disagree about occluder distance -- the raytracer uses the real one, the shadow map's tabled values stand in for a blocker distance pinned to the cascade's own extent -- so RT_SHADOW_SUN_SIZE_CALIBRATION in shadows.sdr is a constant factor that makes a given $SunAngularSize: read as roughly the same softness either way; it's the number to revisit if the shadow map ever grows a real blocker search. Also adds RTAO (raytraced ambient occlusion) sharing the same TLAS as the shadow rays, with lighting-profile-driven radius/strength, and lab controls for RT shadow quality (Low/High), the local light cap, RT shadow samples, RTAO, and an angular-size override for comparing both shadow methods against the same sun. All are safe to change live: they only gate which lights are picked as shadow casters or scale existing uniforms while filling the per-frame light data. Co-Authored-By: Claude Opus 5 <[email protected]>