Acceleration Data Structures
XDG relies primarily on the bounding volume hierarchy (BVH) data structure for accelerating ray tracing operations. The BVH is a hierarchical data structure that organizes primitives (mesh elements) in a scene into a tree of bounding volumes. The BVH is used to accelerate ray intersection tests by allowing the ray to quickly traverse the tree and only test intersections with primitives that are likely to be hit.
Based on the XDG design philosophy (see XDG Design Philosophy), the BVH is constructed by leveraging state-of-the-art ray tracing libraries. On CPUs, XDG relies on the Embree ray tracing kernels for BVH construction and traversal. On GPUs, XDG relies on GPRT as a vendor-agnostic interface for ray tracing pipelines that can leverage the GPU's hardware acceleration for BVH construction or modern software-based implementations of BVH traversal.
Mixed Precision Ray Tracing
The paper "Hardware-Accelerated Ray Tracing of CAD-Based Geometry for Monte Carlo Radiation Transport" discusses the use of mixed-precision algorithms to efficiently handle complex CAD-based geometries in Monte Carlo radiation transport simulations. The key contributions of the paper include leveraging modern ray tracing kernels to significantly speed up the ray tracing process, which is critical for handling the high computational demands of Monte Carlo methods [1].
By integrating the techniques discussed in the paper, XDG achieves faster BVH construction and traversal, leading to more efficient simulations. This is particularly beneficial for applications involving complex geometries and large-scale simulations, where traditional CPU-based methods may fall short in terms of performance.