Ray-Strips: A Compact Mesh Representation for Interactive Ray Tracing (2007) [pdf]

Ray-Strips: A Compact Mesh Representation for Interactive Ray Tracing (2007) [pdf]
gamma.cs.unc.edu

> 6.2 Analysis and Limitations

> The results above show that Ray-Strips are an efficient representation for our tested complex benchmarks. In practice, the memory improvements gained from using Ray-Strips are highly dependent on finding sufficiently long triangle strips to build the hierarchy on. Obviously, this makes our approach unsuitable for models without any mesh connectivity (e.g. without any shared vertices). In that case, the Ray-Strip representation shown in Section 4 becomes an indexed triangle list with a standard BVH (just with the addition on the 2-byte header storing the triangle count) and performance gains are lost. However, the memory overhead added is only very small.Therefore, it is unlikely that there will be a significant performance loss compared to using an indexed triangle list to start with.

> Our current implementation uses the stripification library Stripe[0], which was designed for rasterization and unlike many newer approaches works on general meshes without limitations on the input. Since the computed strips can be sub-optimal for ray tracing,it should be quite possible to further improve the performance of our approaches by designing a stripification algorithm that chooses strips based on ray tracing criteria.

> As presented in Section 3 and 4, our system uses a BVH with axis-aligned bounding boxes as the high-level hierarchy, but is important to note that in principle any acceleration structure can be used for the Ray-Strips. We find that a BVH usually provides a reasonable compromise between rendering speed, flexibility and ease of use. It is also easily updateable so that dynamic scenes can be handled efficiently. If maximum performance for a static scene is desired, a kd-tree may be a better choice and might reduce the memory footprint slightly. Note that Ray-Strips can be updated in the same manner as BVHs, but have the limitation that mesh connectivity cannot change in the animation, e.g. objects cannot “break”.

[0] I can't find this anywhere on the internet. Here is the DOI for the IEEE paper cited (which does not mention this library), DOI: 10.1109/VISUAL.1996.568125