Function calculateBoneMatrices

scripts/test-animation-times.mjs:140–196

(skeleton, nodes, animTransforms)

}

function calculateBoneMatrices(skeleton, nodes, animTransforms) {
    const { joints } = skeleton;
    const boneCount = joints.length;
    const localMatrices = new Array(boneCount);
    const worldMatrices = new Array(boneCount);
    const skinMatrices = new Array(boneCount);

    const processed = new Set();
    const processingOrder = [];

    function addJoint(jointIndex) {
        if (processed.has(jointIndex)) return;
        const joint = joints[jointIndex];
        if (joint.parentIndex >= 0 && !processed.has(joint.parentIndex)) {
            addJoint(joint.parentIndex);
        }
        processingOrder.push(jointIndex);
        processed.add(jointIndex);
    }

    for (let i = 0; i < boneCount; i++) addJoint(i);

    for (const jointIndex of processingOrder) {
        const joint = joints[jointIndex];
        const node = nodes[joint.nodeIndex];

        if (!node) {
            localMatrices[jointIndex] = identity();
            worldMatrices[jointIndex] = identity();
            skinMatrices[jointIndex] = identity();
            continue;
        }

        const animTransform = animTransforms.get(joint.nodeIndex);
        const pos = animTransform?.position || node.transform.position;
        const rot = animTransform?.rotation || node.transform.rotation;
        const scl = animTransform?.scale || node.transform.scale;

        localMatrices[jointIndex] = createTransformMatrix(pos, rot, scl);

        if (joint.parentIndex >= 0) {
            worldMatrices[jointIndex] = multiplyMatrices(
                worldMatrices[joint.parentIndex],
                localMatrices[jointIndex]
            );
        } else {
            worldMatrices[jointIndex] = localMatrices[jointIndex];
        }

        skinMatrices[jointIndex] = multiplyMatrices(
            worldMatrices[jointIndex],
            joint.inverseBindMatrix
        );
    }

    return skinMatrices;
}