public CheckerTexture(Texture odd, Texture even)
 {
     m_OddTexture  = odd;
     m_EvenTexture = even;
 }
 public CheckerTexture()
 {
     m_EvenTexture = new ConstantTexture(new Vector3(0.3f, 0.3f, 0.3f));
     m_OddTexture  = new ConstantTexture(new Vector3(0.9f, 0.9f, 0.9f));
 }