version: "1.0.0" name: ada-procedural-models description: Generate low-poly GLB 3D models from an AdaScript program in Ada Studio (primitives, revolved profiles, triangles, part hierarchy, PBR materials), then place them with Model3DSource. allowed-tools: editor.project.context, editor.model.generate, editor.model.inspect, editor.model.validate, editor.components.describe, editor.scene.get, editor.scene.apply, editor.docs.read, editor.build.start, editor.play.start, editor.task.status

Ada Studio Procedural Models

Use this for props, furniture, vehicles, buildings, trees, robots and other stylized or low-poly objects built from simple shapes. Blender is not available; describe the model in AdaScript and Studio writes a .glb. For blocky voxel art use ada-voxel-models instead. Organic meshes, skinned characters and animation clips cannot be generated this way.

1. Read editor.project.context for the Assets root. Choose a new destination such as Assets/Models/lamp.glb; editor.model.generate never overwrites, so use a new name for each revision.
2. Call editor.model.generate with source (the script) and destination. The script runs in an isolated VM: no files, network, scene or engine access, a 64 KiB source limit and a small time/step budget. Errors come back as text; fix the script and call again.
3. Read the result: parts (names and parents), materials, vertexCount, triangleCount and assetReference (@res://...). Run editor.model.inspect on the path to read the real bounds and confirm the size is what you intended (1 unit is 1 meter).
4. Read editor.components.describe with query Model3DSource, add that component and a Transform to an entity, and set source to the assetReference. Preserve unrelated payload fields and pass the current scene revision.
5. Build, run visible Play and inspect a completed frame before claiming the model looks right. Generation proves the file is valid, not that it reads well.

Script API

Define func build(model). Axes follow the engine: X right, Y up, Z forward. Every shape is centered on its own origin, so build it, then move it with model.place. Shape calls return the part id (a whole number); keep it in a variable. A failed call records the error and the generation is rejected with that message.

Winding: triangles must be counter-clockwise when seen from outside, so cross(b - a, c - a) points out. A lathe profile runs from the top, outward and down the side, back to the axis at the bottom (a solid), as in a cup: profile(0, 1), profile(0.5, 1), profile(0.3, 0), profile(0, 0). Repeat the first point to close a ring profile. Corners sharper than 60 degrees get hard edges; gentler turns are smooth.

Limits: 512 parts, 200,000 vertices in total, sizes up to 1000, 256 profile points, 20,000 custom vertices.

func build(model) {
    model.material(1, 0.55, 0.55, 0.6);
    model.surface(1, 0.8, 0.35);
    model.material(2, 1.0, 0.85, 0.4);
    model.emissive(2, 1.0, 0.8, 0.3);
 
    var lamp = model.group();
    model.name(lamp, "Desk lamp");
 
    var base = model.cylinder(0.12, 0.15, 0.04, 24);
    model.paint(base, 1);
    model.place(base, 0.0, 0.02, 0.0);
    model.parent(base, lamp);
 
    var arm = model.cylinder(0.015, 0.015, 0.45, 12);
    model.paint(arm, 1);
    model.place(arm, 0.0, 0.26, 0.0);
    model.parent(arm, lamp);
 
    var shade = model.cylinder(0.04, 0.12, 0.14, 24);
    model.paint(shade, 1);
    model.place(shade, 0.0, 0.55, 0.0);
    model.parent(shade, lamp);
 
    var bulb = model.sphere(0.045, 12);
    model.paint(bulb, 2);
    model.place(bulb, 0.0, 0.52, 0.0);
    model.parent(bulb, lamp);
}

Craft

• Model at real-world size in meters; an object about 1 m across is easy to frame.
• Put the origin where the object sits or pivots: a prop's feet at y = 0, a door's hinge at its own group.
• Group the parts (model.group() plus model.parent) so the scene gets a named hierarchy that code can animate by part later.
• Use 3-6 materials and distinct roughness values; shape reads better than detail. Segments of 12-24 are enough for small parts.
• Use plane for floors and walls only when seen from the front; thin box parts have both sides.
• Prefer shapes and loops over raw triangles. Loops over many parts are fine in a script, but each call costs script budget, so build repeated detail with a few lathe or box parts.
• Only the calls above exist; do not use print, files, imports or System. A script that fails validation is rejected before running.