computeJointsPerSurface method

Implementation

Map<int, List<Matrix4>> computeJointsPerSurface(
  Map<int, ProcessedNode> processedNodes,
) {
  final jointTransformsPerSurface = <int, List<Matrix4>>{};
  final surfaces = mesh?.surfaces ?? [];
  for (final (idx, surface) in surfaces.indexed) {
    final globalToLocalJointMap = surface.jointMap;
    if (globalToLocalJointMap == null) {
      continue;
    }

    final jointTransforms = (globalToLocalJointMap.entries.toList()
          ..sort(Comparing.on((a) => a.value)))
        .map((e) => e.key)
        .map((jointIndex) {
      final joint = joints[jointIndex];
      if (joint == null) {
        throw StateError('Missing joint $jointIndex');
      }

      final jointNodeIndex = joint.nodeIndex;
      final jointNode = processedNodes[jointNodeIndex];

      final transform = Matrix4.identity()
        ..multiply(jointNode?.combinedTransform ?? Matrix4.identity())
        ..multiply(joint.inverseBindMatrix);

      return transform;
    }).toList();

    jointTransformsPerSurface[idx] = jointTransforms;
  }

  return jointTransformsPerSurface;
}