A method for forming a high spatial resolution perspective rendering from a low spatial resolution voxel space is disclosed. The method comprises steps of: a) initializing a virtual window of predetermined resolution pixels, and placing the virtual window in or near the voxel space; b) sparsely ray-casting a plurality of vectors from a predetermined vantage-point through the virtual window into the voxel space; and c) calculating a visualization-value at a series of positions along each vector. In a position ordering of steps from the vantage-point to the pixel, an accumulated transparency-value threshold is calculated. Values of proximate voxels are interpolated into an interpolated voxel value for each position. The interpolated voxel values are then transformed into a derived visualization-value and transparency value.