55% of every ground pixel was the orthophotograph, at every distance and on every
material. A survey image records WHERE the forest and the scree are well and what a
steep rock face is coloured badly - it is shot through kilometres of air at an angle no
player stands at. The photograph keeps the meadow and the forest and gives the rock back
to the rock, by material and by elevation and never by distance: a distance fade used to
live here and was removed because the photograph has the day's own shadows baked in, so
grass grew dark patches as you backed away and they slid as you walked.
The far tier's rock fallback is the maroon mean, not a neutral grey - TFAST_3 skips the
rock sample and leaves that constant standing in for a whole mountain.
Ortho-classified snow needs altitude now. Bright and unsaturated is what snow looks like
from a satellite and also what a sunlit rock face looks like. Gully snow is gated on the
snow line rather than two absolute heights.
Distance desaturation eased 1.9 -> 1.15: tuned on a valley whose rock was grey anyway.
NOT FIXED, and I want it recorded rather than implied: the Bells themselves are still
not maroon. The near and middle rock is warmer and measurably so, but the distant peak
does not respond to ANY of this - not the rock tint, not the ortho weight, not the snow
line, not the gully gate. Painting sA bright red left it unchanged, so whatever surface
that is, it is not this shader's snow and not this shader's material blend. Somebody
should find out what draws it before tuning any of these numbers further.
400 frames: GL 7.0 s, VK 7.2 s. Backends agree to 0.62/255.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Aerial perspective is a curve now. A low sun shines through far more air than a
high one and shines ALONG the ground rather than down onto it, so density, height
falloff and forward scatter all ride the sun's elevation; overcast thickens the air
and flattens the scatter, because a grey sky has no disc to scatter from. `lowsun`
falls away BELOW the horizon as well as above it, or the middle of the night gets a
dawn's haze with no dawn to justify it.
The term that was missing entirely is distance DESATURATION. Blending a saturated
green ridge toward a saturated blue noon sky leaves a saturated ridge - which is why
the same valley read as a photograph at dusk, where the fog colour happened to be a
warm grey, and as a toy at one o'clock. A surface is now pulled toward its own
luminance faster than the fog itself arrives. Measured far/near saturation at the
camp: 07:00 1.11 -> 0.89, 09:00 1.04 -> 0.93, 13:00 0.98 -> 0.89.
The grade is the hour's too - nine literals bound at the draw, written by
daylight_set now. Noon is the case worth naming: direct sun is warm-white and the
only thing filling a midday shadow is a blue sky, so noon gets a cool balance over a
blue-lifted shadow with hard contrast, and dawn and dusk the reverse. Ground R-B,
lit vs shadowed: 07:00 +42.8/+14.2 -> +48.9/+15.1, 13:00 +32.2/+14.8 -> +25.2/+2.9.
Gain is left alone deliberately: the grade is `c * gain + lift * (1 - c)`, so warming
it warms the whole frame, and warming it at noon made one o'clock yellower than seven
in the morning - the opposite of the point.
The visible sky is relit. Turning a photograph on its axis does not change what
colour it was taken at, so every sunset had a mid-morning blue overhead. An analytic
sky supplies the chroma and the photograph keeps the luminance: the cloud stays where
it is and goes orange at dusk, the zenith goes deep blue at noon, and no second sky
is shipped. It fades out under the horizon and eases off under cloud.
The ground bounce follows the ground, crossing meadow to rock at the map's treeline
instead of being one green constant everywhere including above the scree.
R3D_NOAIR=1 restores all of it, so a before-and-after comes from one binary at one
hour; it joins R3D_NOCLOUD / R3D_NOSHADOW / R3D_NOGI.
Verified on macOS OpenGL, macOS Vulkan (MoltenVK) and Windows Vulkan (RTX 3070 Ti).
Backends agree: mean difference 0.15-0.88/255 within a machine. Across machines the
ORIGINAL renderer already differed by 5.02/255 at 19:12 and this build differs by
2.80, so cross-platform variance is pre-existing and did not grow. 400 frames: GL
7.4 s before and after, VK 7.0 s before and after.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
A reflecting body is clipped to its ellipse like every other unless it is an
unbounded sea, so a map whose reflection belongs to its lake (Maroon Lake, once
its sea sits below it) does not draw that lake's level over every hollow in the
survey. The terrain's wet shore and its forest and scree gates read the carved
lake's line inside its outline (u_lake), the rule grass already used. SPIR-V
regenerated.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
tersun.frag rasterised every terrain patch a second time into a screen buffer, because on OpenGL the
cascade read inside terrain.frag fell off a driver cliff (about 6 ms a frame). Vulkan has no such
cliff: its terrain programs are the SUN_INLINE variant, which evaluates the same two tiers with the
same normal and cross-fade in the ground's own shader, and terrain_draw skips the pass - in the frame
and in the water reflection. OpenGL keeps the pass. R3D_SUN_PASS=1 keeps it on Vulkan, for comparing.
Mac Vulkan town 1759 -> 1692 draws; frames within 2/255 of the pass (15331 px, float rounding). PC camp
1984 -> 1882 draws, 3.9 s for 400 frames either way, self-tests 59/59, validation 0. OpenGL frames
byte-identical.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
