7.1 KiB
Mesh construction operations
Construction commands create a new object and keep input objects intact:
| op | Additional fields |
|---|---|
| sphere | radius, segments: 3–128, rings: 2–128, smooth?: boolean (default true); radial normals across UV seams, including poles |
| cylinder | radius, height, segments: 3–128, smooth?: boolean (default true); centered on Y, radial side normals, flat caps with a hard rim |
| sweep | profile: XY[] (3–128), path: XYZ[] (2–128), caps, material; transported local frames |
| lathe | profile: [radius,height][] (2–128), axis, segments: 3–128, caps, material; zero-radius endpoint poles supported |
| loft | profiles: XYZ[][] (2–128 equal-size rings), closed, caps, material |
| quad_strip | a: XYZ[], b: XYZ[] (equal length 2–4096), closed, material |
| boolean | a, b, mode: union/difference/intersection; closed manifold inputs, bounded candidate pairs, unambiguous source-triangle UV/material/normal transfer |
| voxel_remesh | source, resolution: 8/16/32; bounded FaithC reconstruction with nearest-surface UV/material/weight reprojection |
Boolean and voxel inputs are transformed by their complete scene-node world matrices (including parents); the new output object has an identity frame. Input geometry and nodes stay unchanged. Make linked sources unique and apply enabled modifiers before these direct construction commands.
Boolean and voxel operations refuse seam/crease/pin constraints they cannot map. Booleans also refuse weighted intersection geometry; new intersections do not have a unique rigging interpretation. Existing CSG/FaithC phases run sequentially on the worker; cancellation is checked before/after those bounded phases, and CSG inherits an installed cancellation token. Topology-changing output receives new identities in the new object's scope. Local manifold validation does not certify that arbitrary inputs or deformed shells have no global intersections.
Sphere/cylinder smooth:false selects faceted polygon shading. Smooth shading
does not increase geometry density or round a coarse silhouette. Existing
saved sources keep their stored normals. Sweep/lathe/loft and custom polygon
meshes can use a subsequent normals operation to derive smooth shading with
an explicit crease angle; see Mesh editing operations.
For a glossy surface, author a low surface_material.roughness along with the
desired color and metallic factor; see Surface authoring.
This uses the existing PBR path and does not require image generation.
Surface fibers
For a short fur coat or fine fuzz, prefer surface_material.fur from
Surface authoring. It keeps the base mesh and uses bounded
shader shells. Use the geometry operation below when individual modeled
strands are intentional; its output contributes to GLB size, topology checks,
skinning and triangle cost.
fiber_shell {object,source,count,length,width,seed,material} creates a new
mesh of tapered closed fibers sampled by source triangle area. Counts1–32768,
length0.0001–1m, width0.00001–0.1m and at most half the length, u32 seed;
source input uses the document triangle/work budgets. Geometry, normals, root UV/color sampling
and inherited skin weights are deterministic. Fibers use source mesh coordinates;
copy its object transform to the new object when required. length:0.012,
width:0.0006, count:1400 is a starting yarn-ball surface. This creates
ordinary geometry, not a volumetric fur shader or a strand physics simulation.
For soft bodies pass the separate mesh in deform_objects; only the main body
supplies contact samples. Source is preserved. Context work/byte/topology budgets
apply before allocation; seed changes intentionally create a different surface.
Each bent fiber is admitted against conservative capsules covering both of its
segments, including its embedded root cap. A spatial grid limits nearby
comparisons. Generation tries at most64 candidates per requested fiber and
refuses with an explicit packing-budget error if the requested count cannot
fit; it never silently returns fewer fibers. This keeps distinct fibers apart
in the authored rest mesh. The root still overlaps the source surface by
design, and subsequent deformation does not simulate strand self-collision.
Parametric shapes and architecture
Factories that create a new object from parameters (material optional, 0).
Output shells are closed and outward-wound, UVs are in metres of surface and
curved parts carry analytic corner normals.
box {size,radius?,segments?}rounded box;capsule {radius,height,segments?,rings?}(height = 2*radius is a sphere);cone {radius,top_radius?,height,segments?,smooth?}(top_radius = radius is a cylinder);torus {radius,tube,segments?,sides?};wedge {size}(ramp from -Z top edge to +Z).extrusion {profile,depth,axis?,center?,corner_radius?,corner_segments?,bevel?,bevel_segments?}prism of a 2D profile (any winding), with 2D corner fillets and rounded cap edges.tube {path,radius,segments?,caps?}circular sweep with rotation-minimising frames.wall {path,closed?,height,thickness,base?,openings?,inner_material?,trim_material?}mitred polyline wall; openings{at,width,height,sill?,frame?,frame_depth?,frame_material?,glass?,mullions?}are built as reveals (door when sill is 0), optionally framed and glazed.stair {from,to,width,steps?,thickness?}one closed stair solid.roof {kind:gable|hip|flat,center,size,pitch?,overhang?,thickness?,ridge?,trim_material?,gable_material?,gable_thickness?}.
collider also accepts kind:"hull" (convex hull of the object, support
points in 256 directions for dense objects) and kind:"capsule"; both are
delivered as compact triangle proxies.
Programs
build_program(ops, limits, fetch, cancelled) applies an ordered list of
operation values to a fresh document and compiles it. Besides every ordinary
operation it expands humanoid_rig {height,clips?,sockets?}, bind {object,joint}, bind_all {} and import_glb {alias,prefix,material_base?,transform?}
(bytes resolved through fetch). Failures name the operation index.
Detail and weathering
decal {object,target,center,normal,up?,size,depth?,offset?,material}projects a box onto the target's front-facing triangles (world space) and keeps the clipped surface as a thin new objectoffsetabove it, UVs 0..1 across the decal (V down). Use alpha-masked materials for vents, badges and text.bevel {object,width,segments?,angle?}rounds every edge whose dihedral angle exceedsangleon any closed polygon mesh: faces shrink in plane, edges become quadratic strips, vertices get corner patches; faces keep flat normals and strips interpolated ones. The object is rebuilt (new element IDs).crease {object,angle?,weight?}marks sharp edges with a subdivision crease.- Program macro
weathering {ao?,distance?,edges?,samples?,objects?}casts hemisphere rays against the whole model and writes AO × edge-wear grey levels as vertex colours (multiplying every material). stencil::stencil_textrasterizes a 5x7 stencil font for text layers.