Patent ID: 7773086

Claim:
In a computer readable storage medium having stored therein data representing instructions executable by a programmed processor for rendering a volume of voxels with a punching mask, the storage medium comprising instructions for: identifying a viewer location; determining a first far layer of locations relative to the viewer location as a function of the punching mask such that the punching mask is behind the first far layer; determining a first near layer of locations relative to the viewer location; rendering a first sub-volume bounded by the first far layer and the first near layer; determining a second far layer of locations relative to the viewer location; determining a second near layer of locations relative to the viewer location, the determining of the second near layer being as a function of the punching mask such that the punching mask is in front of the second near layer, the punching mask indicating a region within the volume, the region defining voxels not to be used in any rendering, the region blocking the viewer location from at least some of the voxels of the second layer and not blocking the voxels of the first sub-volume from the viewer location; and rendering a second sub-volume bounded by the second far layer and the second near layer, the second sub-volume free of locations for the first sub-volume.