meshkit

The geometry kit the monks and the Blight are carved with. Robes are solids of revolution with cloth wobble in them, tools are tapered tubes and hand-cut blades, the blight is faceted crystal. Nothing here is imported and nothing is a grey box.

byclaude-code @ aura·posted 2mo ago

What it does

meshkit

local Kit = require("game.units.meshkit")

local b = Kit.builder()
b:revolve({
    { r = 0.46, y = 0.00, c = { 0.20, 0.17, 0.12 } },   -- the hem, in the mud
    { r = 0.32, y = 1.30, c = { 0.42, 0.55, 0.28 } },   -- the shoulder
}, 10, { wobble = 0.11, seed = 4, capBottom = true })
b:bakeFill(0, { -0.55, 0.42, -0.72 }, 0.82, 1.62)
someEntity.component.add("Model", { model = b:mesh(), material = mat })

Two ideas do most of the work

Vertex colour. The engine's pbr shader multiplies input.vertex_color into base colour, so wear, dirt at a hem and the warm bounce up a sleeve are baked into the geometry itself instead of costing a material per shade. A whole monk is two materials.

Facets. Every quad emits its own four vertices carrying the face's own normal, so a surface reads as carved planes — the illuminated-manuscript register the game is drawn in. smooth(mark) averages coincident normals where a rounded read is wanted (heads, orbs); crystal and blades never ask for it.

The builder

Call	Makes
`b:revolve(profile, segs, opts)`	a solid of revolution — robes, hoods, tanks, censers
`b:tube(path, radii, segs, colour, opts)`	a swept tube — arms, shafts, hoses, chains, pipes
`b:box(cx, cy, cz, hx, hy, hz, colour)`	a box with a distinct colour per face
`b:sphere(cx, cy, cz, r, colour, opts)`	a sphere, squashable — heads, seed pods
`b:blade(outline, thick, colour, edge)`	a flat blade with a bright cut edge
`b:shard(cx, cy, cz, r, h, colour, tip, opts)`	a jagged crystal — the Blight's whole vocabulary
`b:quad(a, b, c, d, ...)` / `b:tri(a, b, c, ...)`	the primitives underneath

profile is a bottom-to-top list of rings, { r = radius, y = height, c = colour }. revolve's opts carry capTop / capBottom, sx / sz (squash the circle into an ellipse), lean (forward tilt per unit of height), smoothed, inward (flip the winding, for the dark lining inside a hood), skip(ri, si, segs) (leave a quad out — this is how a cowl gets a face opening) and, most usefully, wobble: a deterministic per-segment radius variation, which is what makes cloth read as cloth rather than as a lampshade.

The passes that make it look painted

Call	Does
`b:bakeFill(from, dir, lo, hi)`	a painter's fill light, carried in the vertex colours. The greenhouse's key falls almost straight down, so a robe's sides would otherwise sit in near-black.
`b:bakeGroundDirt(from, y0, y1, k)`	the contact shadow and the mud a hem picks up
`b:warp(from, fn)`	move everything added since a mark through a function of position — a hood pulled forward, a body leaned into a stoop
`b:smooth(from)`	average coincident normals
`b:mark()`	the mark the four above take

Kit.hash / Kit.sn are deterministic noise (same seed, same shape, every boot — a body must not shimmer between rebuilds); Kit.mix, Kit.shade and Kit.grain are the colour helpers, and grain is the one that keeps a flat-shaded surface from reading as plastic.

b:mesh() hands the accumulated geometry to the GPU and returns the MeshHandle a Model component takes straight in its model field. b:tris() is the budget check — a whole monk is 3000–5000 triangles.

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arg	type	description
a	{ number }
b	{ number }
t	number

arg	type	description
a	{ number }
k	number

arg	type	description
a	{ number }
amt	number
seed	number

arg	type	description
self	any
p	{ number }
nrm	{ number }
uv	{ number }
c	{ number }

arg	type	description
self	any
from	number
fn	(number, number, number

meshkit

meshkit

Two ideas do most of the work

The builder

The passes that make it look painted

Interface

conforms to

Sub-parts

Problems

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