Hybrid Hidden-Line Processor Edge Visibility

The algorithm segments edges into two categories: silhouette edges (which define object boundaries) and non-silhouette edges (internal edges). By separating these edge types and applying different processing rules, the algorithm achieves both speed (by not intersecting all edges) and accuracy (by correctly identifying visible silhouette edges through plate protection)

The patent applies plate protection specifically to silhouette edges rather than all edges uniformly. This local quality approach ensures that silhouette edges (which are critical for accurate object boundary representation) receive enhanced protection against being incorrectly hidden, while non-silhouette edges use standard depth buffering, thus balancing accuracy and performance

The algorithm extracts and processes only the critical subset of edges (silhouette edges) that define object boundaries, rather than processing all edges as in traditional object space algorithms. This extraction approach maintains accuracy for visible boundaries while dramatically reducing computational complexity and memory requirements

Instead of performing complete edge intersections for all edges (excessive action), the algorithm performs partial action by only intersecting non-silhouette edges with silhouette edges to determine visibility changes. This partial processing achieves sufficient accuracy for hidden-line removal while avoiding the computational burden of full object space processing