Comparison of Point-in-Polygon Algorithms for Modeling Terrain in High-Fidelity Groundshock Simulations

High-fidelity groundshock simulations model shock propagation through ground material following an explosive event and require mathematical representations of all geologic materials and geometries. Finite element groundshock codes typically depend on the ability to model terrain and/or subsurface geology by assigning elements from a mesh to a material based on whether that element lies inside or outside of a 3D stereolithography (STL) file (the “point-in-polygon” problem). For ideal, error-free STLs this assignment is easy. However, real-world STLs often have issues that can lead to incorrect element assignments. In this talk we discuss the implementation of multiple algorithms (ray casting, solid angle, and unit sphere) for solving the 3D point-in-polygon problem presented by modeling terrain with real-world STLs. Results are presented on the issues associated with each, and each algorithm is rated for ease of use, computational efficiency, and accuracy.

PRESENTER

Hariprasad, Daniel
dhariprasad@ara.com
703-329-0200

Applied Reserach Associates, Inc.

CO-AUTHORS

Patel, Michael
mapatel@ara.com

Harvey, Allen
aharvey@ara.com

CATEGORY

Computational Structural Mechanics (CSM)

SYSTEMS USED

Mustang, Narwhal, Carpenter

SECRET

No