Vertices, UVs and smoothing

EditableMesh is geometry you can change from scripts and from the editor. Every method works in the object's local space, marks the mesh as changed (the GPU gets a new version) and leaves the normals alone - call recalculate_normals() when lighting matters.

Getting a mesh

if ctx.make_editable(entity) {            // turns primitive:cube/sphere/... into an editable mesh
    if let Some(mesh) = ctx.editable(entity) {
        mesh.twist(Vec3::Y, 30.0);
        mesh.recalculate_normals().ok();
    }
}

For models from files (.glb, .obj) the editor's Geometry window creates the editable mesh (the EditableMesh component).

Vertex access

Method	Description
vertex_count(), position(i), set_position(i, p)	read and write one vertex
bounds()	(min, max) of the bounding box
map_positions(|i, p, n| new_position)	any custom deformation
select_sphere(center, r), select_half_space(point, normal)	select vertices
translate_vertices(&ids, delta), translate, scale_about, transform(mat)	shifts and matrices

Deformers

Method	Result
wave(direction, displace, amplitude, wavelength, phase)	a travelling wave (flags, water)
twist(axis, degrees_per_metre)	twisting
taper(axis, start, end)	narrowing or widening along an axis
bend(along, axis, degrees_per_metre)	bending
inflate(amount)	push along the normals
noise_displace(&noise, amplitude, time)	irregularities from noise (rocks, terrain)
smooth(iterations, factor)	Laplacian smoothing

let noise = EditableMesh::default_noise(2.0, 7);   // Perlin, frequency 2, seed 7
mesh.noise_displace(&noise, 0.15, ctx.elapsed());  // a "breathing" rock
mesh.smooth(2, 0.4);
mesh.recalculate_normals().ok();

UV unwrapping

Method	When to use
project_planar(axis, scale)	floors, walls, decals: scale is metres per texture repeat
project_cylindrical(scale)	trunks, columns, bottles
project_spherical()	balls, planets
normalize_uv(margin)	fit the UVs into 0..1 (for baking)
transform_uv(scale, rotation_deg, offset)	scale, rotate and shift the unwrap

mesh.project_planar(Vec3::Y, 2.0);   // seen from above, 2 m per repeat
mesh.transform_uv([1.0, 1.0], 45.0, [0.0, 0.0]);

Normal smoothing

Method	Result
recalculate_normals()	smooth normals weighted by triangle area
flat_normals()	faceted: every triangle has its own normal
smooth_normals(angle)	smooth, but edges sharper than angle degrees stay hard (like Auto Smooth)

For a low-poly style use flat_normals(); for props with bevels use smooth_normals(35.0).

Limits

An editable mesh is limited to 100 000 vertices and 600 000 indices. For very large meshes deform in the shader (the Wave offset and Wind sway nodes).