Parts and shapes

Each part needs an id, a geometry and a material. The id never changes. Optional fields: name, parent (another part's id), local position, rotation (XYZ radians), positive scale, solid, animation, light and effects. A child moves with its parent. Blank rejects a part that is its own ancestor, and any name that points to nothing.

Five coherent low-poly props: a tree, a gate, a lantern, a rock and a chest — Sunward Grove: five props made from the same six shapes and one set of colours.

Shapes

`kind`	Parameters
`box`	`size: [x, y, z]`, optional `bevel`
`cone`	`radius`, optional `top_radius`, `height`, `segments` 3–32
`ico_sphere`	`radius`, `subdivisions` 1–3
`torus`	`radius`, `tube`, `segments` 3–64, `sides` 3–12
`loft`	`segments` 3–32 and 2–16 `rings`, each with `center`, `radius`, optional `phase`
`prism`	3–32 XY `outline` points, `depth`, optional `bevel`

Boxes, cones, spheres, tori and prisms are centred on the part's origin. Loft rings use the centres you give them. All meshes are low-poly with flat shading.

Light and effects

light adds a point light: color as linear [r, g, b], intensity and range in metres. effects adds up to eight particle effects, such as floating sparks: {"id", "count", "seed", "size", "intensity", "color", "emitter": {"kind": "sphere", "radius", "thickness"}, "motion": {"orbit", "wander", "speed"}, "pulse": {"depth", "rate"}}.