public void DrawBasis(Matrix basis, float scale)
{
Vector3 pos = Vector3.TransformCoordinate(Vector3.Zero, basis);
Vector3 xaxis = Vector3.TransformNormal(Vector3.UnitX * scale, basis);
Vector3 yaxis = Vector3.TransformNormal(Vector3.UnitY * scale, basis);
Vector3 zaxis = Vector3.TransformNormal(Vector3.UnitZ * scale, basis);
DrawLine(pos, pos + xaxis, Color.Red);
DrawLine(pos, pos + yaxis, Color.Lime);
DrawLine(pos, pos + zaxis, Color.Blue);
}