Fast overlap detection between hard-core colloidal cuboids and spheres. The OCSI algorithm

TL;DR

The paper introduces the OCSI algorithm for fast collision detection between cuboids and spheres, demonstrating superior performance and ease of implementation compared to existing methods in computer graphics and colloidal science.

Contribution

The paper presents the OCSI algorithm, a new OpenMP-based method for efficient collision detection between cuboids and spheres, with improved performance and usability.

Findings

OCSI outperforms traditional algorithms like QRI and QRF in speed.

OCSI maintains performance regardless of object geometry.

OCSI offers a more accessible implementation compared to SSE-based methods.

Abstract

Collision between rigid three-dimensional objects is a very common modelling problem in a wide spectrum of scientific disciplines, including Computer Science and Physics. It spans from realistic animation of polyhedral shapes for computer vision to the description of thermodynamic and dynamic properties in simple and complex fluids. For instance, colloidal particles of especially exotic shapes are commonly modelled as hard-core objects, whose collision test is key to correctly determine their phase and aggregation behaviour. In this work, we propose the OpenMP Cuboid Sphere Intersection (OCSI) algorithm to detect collisions between prolate or oblate cuboids and spheres. We investigate OCSI's performance by bench-marking it against a number of algorithms commonly employed in computer graphics and colloidal science: Quick Rejection First (QRI), Quick Rejection Intertwined (QRF) and SIMD Streaming Extensions (SSE). We observed that QRI and QRF significantly depend on the specific cuboid anisotropy and sphere radius, while SSE and OCSI maintain their speed independently of the objects' geometry. While OCSI and SSE, both based on SIMD parallelization, show excellent and very similar performance, the former provides a more accessible coding and user-friendly implementation as it exploits OpenMP directives for automatic vectorization.