trianglesOf static method

ModelGeometry? trianglesOf(ModelData data, { int? mesh, })

The triangles of data in engine axes (+Y down), placed by its nodes in its rest pose: of mesh mesh alone, or of every mesh when null. Null when there are none.

Implementation

static ModelGeometry? trianglesOf(ModelData data, {int? mesh}) {
  final positions = <double>[];
  final indices = <int>[];
  final point = Vector3.zero();
  data.forEachNode((node, modelFromNode) {
    final index = data.nodes[node].mesh;
    if (index == null || index >= data.meshes.length) return;
    if (mesh != null && index != mesh) return;
    final m = gltfToEngine.multiplied(modelFromNode);
    for (final p in data.meshes[index].primitives) {
      final base = positions.length ~/ 3;
      for (var v = 0; v < p.vertexCount; v++) {
        final o = v * kVertexFloats;
        point.setValues(p.vertices[o], p.vertices[o + 1], p.vertices[o + 2]);
        m.transformPointInto(point, point);
        positions.addAll([point.x, point.y, point.z]);
      }
      indices.addAll(p.indices.map((i) => i + base));
    }
  });
  if (indices.isEmpty) return null;
  return ModelGeometry(
    Float32List.fromList(positions),
    Uint32List.fromList(indices),
  );
}