An Interactive Display Algorithm for CSG using Scanline Algorithm

Abstract

In the hidden-surface removal procedure, a one-dimensional Boolean operation in the depth direction is used to find a visible surface of the shape defined by the constructive solid geometry (CSG) instead of a depth comparison. The Boolean operation, however, refers to the definition many times while generating the image, so it takes much time to complete.
We have used the spanning scanline algorithm to display the shape of the Boolean combined primitives of the polyhedra. It describes the Boolean combination by using the pattern matrix and speeds up the one-dimensional Boolean operation by using incremental calculation. The number of Boolean operation executions is drastically reduced by using the connection information at the adjoining facets. This results in a robust and high-speed CSG display algorithm that can be used for interactive applications.