Fast Ray-Triangle Intersections by Coordinate Transformation

Ray-triangle intersection is a crucial calculation in ray tracing. We present a new algorithm for finding these intersections, occupying a different place in the spectrum of time-space tradeoffs than existing algorithms do. Our algorithm provides faster ray-triangle intersection calculations at the expense of precomputing and storing a small amount of extra information for each triangle. Running under ideal experimental conditions, our algorithm is always faster than the standard Möller and Trumbore algorithm, and faster than a highly tuned modern version of it except at very high ray-triangle hit rates. Replacing the Möller and Trumbore algorithm with ours in a complete ray tracer speeds up image generation by between 1 and 6%, depending on the image. We have coded our method in C++, and provide two implementations as supplements to this article.