GrassKind (grass_kind.ludic) carries what grass.ludic, grass_gpu.ludic, grass.vert, grass_cull.comp and
model.frag's BLADE path held as constants: the cell, s0 / d0 / radius, the row bands and rows, the blade
profile (neck, root, swell, tip, bend), the heights, clumps, widths and arch, where it grows (slope, snow,
the photograph's test), the root / tip / gone-to-seed colours, the far tufts, the root occlusion, the
roughness, the sheen and the wind. Its defaults are those constants exactly, so a game that sets nothing
draws as before. The shaders read them as u_gk_* (the cull as five more Params vec4s, 288 bytes);
grass_reset.comp writes each band's index count so a kind of other rows reaches the draw in order.
grass_quality holds the kind to a settings tier (never denser, never farther); R3D_GRASS_* still win.
grass_profile_w / _bend are the one profile, for the meshes and a game's preview. grass.mesh takes only
the cell: the rest of it is an older copy that already differs from grass.vert, left as it draws.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
gltf_factors reads pbrMetallicRoughness.baseColorFactor, metallicFactor, roughnessFactor and the
emissiveFactor into the primitive (pr.fac), and prim_factors hands them to every program that draws its
textures (actors, the scatter's meshes and levels, the impostor bake) as 1 - factor, so a program never
given them - or a material that gives none (pr.fac null) - multiplies by 1 and draws as before. An
untextured material with a colour (or a metal/roughness) samples a pure white for it, so the factor is
exactly what it draws: horse_cornea is its own colour, not the 200 grey every untextured part had.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The user saw kit grass, ferns and flowers lit up at night. Nothing was
emissive and every layer draw binds the scene's lighting; what differed was
occlusion. At night the sky's light is nearly all the light, and it is
scaled by ambient occlusion: the meadow's blades are heavily occluded near
the ground, while a kit plant's own AO map knows nothing of the grass around
it, so it took the full sky. By day the sun hides the difference.
model.vert hands on each vertex's height above the model's base (v_lh), and
a non-blade FOLIAGE plant under 2 m scales its AO from 0.35 at the ground to
1 at 0.9 m. Crowns and the blades are untouched.
Measured in the lab (R3D_AT=tree, same binary, old and new SPIR-V): the fern
against the meadow beside it was 2.05x at 23:00 and 1.66x at 13:00; now 1.58x
and 1.60x - the same relation by night as by day. The flowers' brightest
tenth at night 78 -> 52. The noon frame moves 8.4% of pixels past 8 (the fern
and flower bases a little darker; run-to-run noise is part of that).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- grass_cull.comp decides each candidate blade once a frame (place, ground, density, water,
slope, frustum, colour field) and writes survivors into three bands by distance, one indirect
draw each; grass_inst.vert only bends and places the vertices. OpenGL keeps grass.vert's
per-vertex path; R3D_GRASS_GPU=0 compares
- compute programs take sampled textures after their buffers (gpu_compute_tex / gpu_dispatch_tex),
and every dispatch now records a compute-to-draw memory barrier
- the blades as a sward: 4 m cells, bands with five, three and one-quad blades, spacing doubling
every 18 m to 70 m, never narrower than a pixel; lit facing the sun and leaning to the sky,
shadow looked up above the ground (it read the terrain as its caster), a colour ramp that
leaves only the sheath dark, clumps, dry patches and a tussock shade worked out per blade
- scatter layers flagged grass are skipped while the blades draw (and under R3D_NOGRASS);
R3D_BLADES, R3D_NOBLADES win over the game's setting; R3D_GRASS_S0/D0 for measuring
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Input.text, App.monitor_count / window_to_monitor / window_fixed,
gl_sleep_us, and the grass and collide changes, uncommitted on main and
depended on by the game; carried here so the language work starts from
what the game actually uses. main's working tree is untouched.
layer_flutter's mask was the vertex's height alone, so on a ten metre aspen every part of
the trunk above 1.2 m trembled with the leaves and the bole read as cloth. What separates
a leaf from a bole is distance from the model's centre line, not height; the mask is
radial now, and small plants keep the old one because a flower is all leaf.
NEAR_FADE dithers tree foliage out inside arm's length of the camera, in the depth
prepass, so the lit pass never sees those pixels and the equal-depth optimisation is
untouched. gl_Position.w is the view depth, so it costs one varying and no uniform.
Blades, cards and flowers are excluded - they live at the player's feet - and the shadow
pass keeps every leaf.
daylight_hand takes a reach in metres. The falloff was an inverse square windowed between
26 and 6 with both numbers hard-coded: two per cent of its own near field at ten metres,
so a torch lit your boots. It is a gentle power out to the reach now.
Measured in Maroon Lake, twice per side: the crown mask moves 1.7% of an aspen frame and
nothing at all in the meadow under it; the near fade moves 7.1% of a first-person frame
at a conifer and 0% where there is no foliage in the lens; the torch's reach lifts the lit
ground 20 to 45% and leaves the sky bit-identical.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
layer_flutter(l, v) gives a scatter layer a per-leaf tremble. The vertex stage offsets
each leaf by a phase taken from its own place on the card, so neighbouring leaves are
never in step, and writes the result out as a varying the fragment stage uses to flash
the leaf's pale underside as it turns - which is the part that reads, since a still
frame of a tremble is a still frame of nothing. One uniform, one varying, no extra pass.
And the sway itself was measured in METRES: hgt * hgt * 0.35 is right for a 40 cm
flower and puts ten metres of sideways into a 14 m trunk, so every tall tree in the
valley stood bent over like a fishing rod. It is a fraction of the model's own height
now - the tip moves a few per cent of the tree whatever the tree is, and the base does
not move at all.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Foliage roughness was pinned to 1.0 and grazing Fresnel switched off, so nothing green
in the game had a highlight anywhere. The glint off waxy leaves and wet needles is most
of what makes a stand look alive rather than painted.
The reason it was off is real: a crown is card quads, and at a grazing angle the card's
normal is a lie, so a specular lobe frosted whole crowns white against the sky. The sheen
returns as its own term gated on exactly that - it fades as the card turns edge-on, which
is where its normal stops meaning anything. A tight lobe for the glint, a weak wide one
for the waxy rim, nothing at the angles that frosted.
Translucency reaches 260 m rather than 140, and a dense crown passes 0.45 of it rather
than 0.3, so a backlit stand glows for as far as you can see it.
400 frames: GL 7.1 s, VK 7.4 s. Backends agree to 0.14/255.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Needle-card crowns are many cut-out quads deep and a discarding shader turns early depth
rejection off, so every card behind the front one ran the full lighting shader. The near
tree LODs now write depth first (depth.frag, the same alpha coverage test), terrain under
them is rejected before shading, and the lit pass draws them with no discard and an equal
depth test (invariant gl_Position). R3D_NOPREPASS=1 restores the old path.
Dense forest on a Windows PC: 61 -> 78 fps at 3840x2160, 116 -> 164 fps at 1920x1080.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
`Gl.*` binds the whole OpenGL 4.1 core API — every entry point of the
platform gl3.h with every GL_* constant, generated by `ludic-dev glgen`
with per-call ABI thunks. Windowed builds get an NSOpenGLContext on the
existing window at Retina resolution; headless builds render into an
offscreen CGL context, so a program that uses Gl.* renders and
screenshots identically under the test harness. It links gl.ll, the
thunks and OpenGL.framework only when used; every other build stays
byte-identical.
packages/ludic.render3d is a physically based renderer written on that
surface: HDRI image-based lighting, GPU-generated terrain with scanned
PBR materials, CDLOD, cascaded shadows, glTF with skinning, instanced
vegetation with impostors, procedural grass, water, SSAO, and an HDR
pipeline with bloom, auto-exposure and ACES.
It also carries this session's work on it: the terrain at half its cost
(10.3 -> 5.4 ms of frame), the streaming hitch that got worse the longer
you played, a resize that emptied the world, and the packaging that lets
a game use the renderer from its own repository — `ludic assets`, the
material manifest shipping with the package, and shader lookup falling
back to the install root. See changes/ for each, with its numbers.
The camping game that drove all of it has moved out to its own
repository, Maroon Lake; examples/rendering/smooth.ludic stays as the
renderer's example here.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
