- 
		  Right-click the cloud of points or mesh and select 
			 Properties.
		  
		  The 
			 cells found in the cloud of point or mesh are listed
			 below the viewer.
		   
- 
		  Select the 
			 Protected 
			  check box for the cell to protect.
		  
		
When you start 
		Remove or 
		Filter , the protected cells or scans are shown as
		low-intensity elements (meaning they cannot be filtered nor removed) and are
		not taken into account.