Abstract This paper compares two image space hidden surface removal algorithms for polygonal scenes. These are the z‐buffer and scan‐line algorithms. There is first an overview of each algorithm, followed by a simulation experiment, designed to compare the number of polygons per second which can be rendered by each algorithm. The simulation varies the number of polygons in the scene, and the size and distribution of polygons over the display. The results suggest that the z‐buffer is preferred for a large enough number of polygons, however, smaller polygons and uniform distribution of polygons favour the scan‐line approach. The analysis does not take into account the complexity of the shading rule, which is likely also to favour the scan‐line method.

BrouHaHa is a portable implementation of the Smalltalk-80 virtual machine interpreter. It is a more efficient redesign of the standard Smalltalk specification, and is tailored to suit conventional 32 bit microprocessors. This paper presents the major design changes and optimization techniques used in the BrouHaHa interpreter. The interpreter runs at 30% of the speed of the Dorado on a Sun 3/160 workstation. The implementation is portable because it is written in C.