/**
  * Traverse a class of voxel and material types. May be much faster then full grid traversal for
  * some implementations.
  *
  * @param vc The class of voxels to traverse
  * @param mat The material to traverse
  * @param t The traverer to call for each voxel
  */
 public void findAttribute(VoxelClasses vc, long mat, ClassAttributeTraverser t) {
   ((AttributeGrid) grid).findAttribute(vc, mat, t);
 }
 /**
  * Traverse a class of voxels types over given rectangle in xy plane. May be much faster then full
  * grid traversal for some implementations.
  *
  * @param vc The class of voxels to traverse
  * @param t The traverer to call for each voxel
  * @param xmin - minimal x - coordinate of voxels
  * @param xmax - maximal x - coordinate of voxels
  * @param ymin - minimal y - coordinate of voxels
  * @param ymax - maximal y - coordinate of voxels
  */
 public void findAttribute(
     VoxelClasses vc, ClassAttributeTraverser t, int xmin, int xmax, int ymin, int ymax) {
   ((AttributeGrid) grid).findAttribute(vc, t, xmin, xmax, ymin, ymax);
 }
 /**
  * Traverse a class of material types. May be much faster then full grid traversal for some
  * implementations.
  *
  * @param mat The material to traverse
  * @param t The traverer to call for each voxel
  */
 public void findAttribute(long mat, ClassAttributeTraverser t) {
   ((AttributeGrid) grid).findAttribute(mat, t);
 }