calibrate-model

Original：🇺🇸 English

Translated

Use before repeatedly placing GLB models in PlayCanvas Engine, React, or Web Components to measure each asset once and record its uniform scale, grounding offset, and yaw correction in a stable nested transform.

3installs

Sourceplaycanvas/skills

Added on2026-08-22

NPX Install

npx skill4agent add playcanvas/skills calibrate-model

SKILL.md Content

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Model calibration

Use the

inspect-glb

skill to measure every unique GLB before mass placement. Rely on

dims

and

groundOffset

for contact-accurate placement only when it reports

boundsSource: vertices

. Store one tuning record per asset:

ts

const ASSET_TUNING = {
    model: {
        boundsSource: 'vertices',
        aabb: { min: [-4, -1, -9], max: [4, 6, 9] },
        dims: [8, 7, 18],
        center: [0, 2.5, 0],
        groundOffset: 1,
        intended: { dimension: 'length', size: 18 },
        scale: 0.9,
        y: 0.9,
        yaw: 180
    }
} as const;

Calculate the record

Pick and record the intended dimension and size: character height, building footprint, or vehicle length. Base it on world units or an already calibrated reference model.

Calculate

scale = intendedSize / measuredDimension

.

For a floor-resting model, calculate
```
y = groundOffset * scale
```
. Record a deliberate offset for waterlines, embedded objects, or airborne models.
Confirm directional facing once in the running app, as the
```
apply-conventions
```
skill describes. PlayCanvas entities face -Z while glTF convention is +Z, but asset packs vary.
Retain
```
boundsSource
```
,
```
aabb
```
,
```
dims
```
,
```
center
```
,
```
groundOffset
```
, and the intended size with
```
{ scale, y, yaw }
```
. Use the scaled footprint and centre for initial spacing; do not re-derive or add per-instance nudges.

Keep gameplay position and heading on an outer semantic root, and seat the model on one predictable reference point beneath it so a root position means the same thing for every asset: by default the footprint centre over the base. Apply the authored yaw on a wrapper, then the scale and the full offset on the render child inside it, so an off-centre pivot is compensated in the authored frame and never re-rotated by the yaw or by gameplay heading:

ts

const yaw = new Entity('yaw');
yaw.setLocalEulerAngles(0, t.yaw, 0);
const visual = instantiate(asset);
visual.setLocalScale(t.scale, t.scale, t.scale);
visual.setLocalPosition(-t.center[0] * t.scale, t.y, -t.center[2] * t.scale);
yaw.addChild(visual);
root.addChild(yaw);

Keep

as the local correction that brings the measured minimum to the root plane; the X and Z terms bring the footprint centre onto the root axis. Place that root at a measured support point. A support name or global AABB maximum is not a surface measurement. Use an authored mount point or runtime support query for curved or stepped geometry. Treat skinned bounds as bind-pose estimates and confirm foot contact in the active poses.

Read exactly one reference matching the code being edited: direct Engine, React, or Web Components. Choose from imports and markup, not installed dependencies alone.

calibrate-model

NPX Install

Tags

SKILL.md Content

Model calibration

Calculate the record