  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.
