10 research outputs found
RT-kNNS Unbound: Using RT Cores to Accelerate Unrestricted Neighbor Search
The problem of identifying the k-Nearest Neighbors (kNNS) of a point has
proven to be very useful both as a standalone application and as a subroutine
in larger applications. Given its far-reaching applicability in areas such as
machine learning and point clouds, extensive research has gone into leveraging
GPU acceleration to solve this problem. Recent work has shown that using Ray
Tracing cores in recent GPUs to accelerate kNNS is much more efficient compared
to traditional acceleration using shader cores. However, the existing
translation of kNNS to a ray tracing problem imposes a constraint on the search
space for neighbors. Due to this, we can only use RT cores to accelerate
fixed-radius kNNS, which requires the user to set a search radius a priori and
hence can miss neighbors. In this work, we propose TrueKNN, the first unbounded
RT-accelerated neighbor search. TrueKNN adopts an iterative approach where we
incrementally grow the search space until all points have found their k
neighbors. We show that our approach is orders of magnitude faster than
existing approaches and can even be used to accelerate fixed-radius neighbor
searches.Comment: This paper has been accepted at the International Conference on
Supercomputing 2023 (ICS'23
Generalized Neighbor Search using Commodity Hardware Acceleration
Tree-based Nearest Neighbor Search (NNS) is hard to parallelize on GPUs.
However, newer Nvidia GPUs are equipped with Ray Tracing (RT) cores that can
build a spatial tree called Bounding Volume Hierarchy (BVH) to accelerate
graphics rendering. Recent work proposed using RT cores to implement NNS, but
they all have a hardware-imposed constraint on the type of distance metric,
which is the Euclidean distance. We propose and implement two approaches for
generalized distance computations: filter-refine, and monotone transformation,
each of which allows non-euclidean nearest neighbor queries to be performed in
terms of Euclidean distances. We find that our reductions improve the time
taken to perform distance computations during the search, thereby improving the
overall performance of the NNS