private void pushMatrix(MD3Object md3, string tag_id)
 {
     for (int i = 0; i < md3.tags.Count; ++i)
     {
         if (md3.tags[i].strName == tag_id)
         {
             //cache md3.tags[i].cache_matrix
             Matrix m = md3.getMatrixTag(i);
             push_matrix = m * push_matrix;
             break;
         }
     }
 }
 private Matrix getTagMatrix(MD3Object md3, string name)
 {
     Matrix m = Matrix.Identity;
     for (int i = 0; i < md3.tags.Count; ++i)
     {
         if (md3.tags[i].strName == name)
         {
             m = md3.getMatrixTag(i);
             break;
         }
     }
     return m;
 }