Fast Triangle Strip Generation and Tunneling for Different Cost Metrics

Abstract

Triangle strips provide a memory-efficient representation of triangle meshes. In the ideal case, they allow to encode a mesh of n faces with $n + 2$ vertices. All modern graphics interfaces offer a primitive type for triangle strips to disburden the host/device bottleneck and save graphics memory. Although modern 3D rendering pipelines mainly utilize triangle lists, strips still offer significant benefits in two-dimensional applications, e.g. the visualization of polygons in orthographic maps. Encoding a regular mesh into an optimal triangle strip representation is an NP-complete problem. Therefore, multiple heuristic techniques for different cost metrics have been proposed and implemented. In this paper, we provide an overview of related approaches and propose a unified cost model to rate their quality. Furthermore, we introduce a faster and more flexible implementation for triangle strip generation. It extends an established key technique, the tunneling operator, with a new algorithm for circle detection. A concluding benchmark compares our code with existing solutions and outlines its superior performance in most use cases.

8 Appendix

See Tables 1–6, Figs. 14 and 15.

Table 1 suzanne (966 triangles, 1250 runs)

Table 2 triceratops (5660 triangles, 250 runs)

Table 3 horse (96,966 triangles, 100 runs)

Table 4 armadillo (345,944 triangles, 5 runs)

Table 5 happy_buddha (1,087,716 triangles, 1 run)

Table 6 Reducing the number of strips with the tunneling stage of rm_tristripper (pairs as preprocessing algorithm)

Fig. 14

The triceratops model before tunneling. The pairs preprocessing algorithm has created 2812 strips consisting of two triangles and 36 isolated strips that contain a single triangle

Fig. 15

The triceratops model after tunneling; only 59 strips remain