getTriangleNormals method
Get the three vertices for triangle i.
Implementation
void getTriangleNormals(int i, Vec3 a, Vec3 b, Vec3 c) {
final i3 = i * 3;
getNormal(indices[i3], a);
getNormal(indices[i3 + 1], b);
getNormal(indices[i3 + 2], c);
}