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Ballista

A low-poly Roman field ballista on a timber trestle stand: twin torsion skeins drive two tapered arms, a V-string nocks onto a draw slider, and a rear winch cranks the span. Loops an 8-second spanning-and-aiming drill.

Original GLB215 KB Poster

Left rail: colours and the 4 knobs the agent wrote into this model — they rebuild the geometry and go into your download. Right rail: looks for the viewer. Drag to orbit, scroll to zoom.

Triangles: 1,840
Vertices: 2,623
Meshes · materials: 67 · 9
Size (W × H × D): 2.6 m × 1.5 m × 2.3 m
File: GLB · 215 KB
Animation: scene-motion · 8.0s
Style: Low-poly
Collection: Siege Camp

Palette · named materials

frame#3d2a1c
timber#634d36
rope#bf9769
cord#d2bca2
metal#7e8c9a
army#c05959
runner#8f7356
iron#1b1b22
canvas#9a7142

Use it

import { GLTFLoader } from "three/addons/loaders/GLTFLoader.js";

const gltf = await new GLTFLoader().loadAsync(
  "https://assets.stoicsoft.com/1designtool/3d/models/siege-camp-ballista/8f12bd30f6/model.glb"
);
scene.add(gltf.scene); // metres, +Y up, front faces +Z

const mixer = new THREE.AnimationMixer(gltf.scene);
gltf.animations.forEach((clip) => mixer.clipAction(clip).play());
// in your loop: mixer.update(delta)

How it was made

The brief given to 1DesignTool's “3D object” template:

Ballista for the Siege Camp kit. Design it as one clear asset at believable real-world scale for that setting (state the size in metres in meta.notes), with its main parts modelled and named, readable at thumbnail size and from every orbit angle. It moves: author a seamless baked loop (2–12 s) with every pivot exactly at its hinge, axle or swivel, and keep the base still. This is one part of the Siege Camp kit (Low-poly style, flat-lowpoly direction): An army camped outside the walls. Use ONLY the kit palette, by name: canvas tan #bf9769, mud #634d36, steel #7e8c9a, faded red #c05959, canvas tan dark #9a7142, mud dark #32261b, canvas tan light #d2bca2, mud light #8f7356, soot black #1b1b22, warm white #f2ede2, mid grey #7d828c, dark wood #3d2a1c. Every material's `name` must be exactly the palette colour it uses — the GLB carries these names so the kit recolours as one; an unnamed material fails delivery. Kit knob: expose a param `armyColours` (0–1, default 0.5) for the kit's "Army colours" setting wherever it makes sense on this part, and keep that id.

Agent: Devin · SWE-2 Max in 1DesignTool
Direction: Low-poly · family abstract-kinetic
three-check PASS · glb-lint PASS

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Named parts · 22

Ballista
Trestle stand
Front-left leg
Front-right leg
Rear-left leg
Rear-right leg
Base frame
Turntable
Elevating carriage
Bolt rail
Spring frame
Left torsion skein
Right torsion skein
Army shield boss
Left arm
Right arm
Draw slider
Bolt
Winch
Left bowstring
Right bowstring
Winch rope

Note: Believable field size: ~1.54 m tall, ~1.9 m arm span at rest, ~2.4 m long — a light Roman ballista on a fixed trestle. Metres, +Y up, front faces +Z, origin at bottom centre. The baked 8 s clip is a spanning drill: the winch cranks the slider back, the string draws and the arms sweep in their skeins, while the turntable yaws and the carriage nods; the stand never moves. Bowstring and winch rope are rigid segments re-aimed per frame — they stretch ~8% at full draw for readability. armyColours scales the faded-red heraldry (shield boss, arm bands, bolt fletching). Materials are flat-shaded, metalness 0, named by palette colour. GLB carries 9 shared materials, 22 named parts, 1 clip ('scene-motion', 27 tracks).