Monday, June 23, 2008

GPU Curve-Curve Intersection

I was traveling this weekend so I printed out a couple of recent conference papers to read while in the airports.  The SolidModeling annual conference was just held in early June.  Usually it has some very interesting results for those of us that dabble in solid modeling.  I came across a paper that was an extension of something I saw last year.

Sara McMains' research group out of UCB has been doing some great work on GPU-based NURBS generation and manipulation.  My research last summer that culminated in the genesis of Wildcat parallels much of what her group published in "Direct Evaluation of NURBS curves and surfaces on the GPU."  The approach you see in Wildcat for using the GPU to generate NURBS curves and surfaces is very similar to hers.

This year her group has followed that paper with "Performing Efficient NURBS Modeling Operations on the GPU."  I will let you read it because it is pretty good.  They tend to use too many passes on the GPU while I consolidate down to one or maybe two passes, but I like their approach.  I have not reviewed it in detail, but their stream-reduction algorithm seems very promising.

So, today I took some time and reworked my curve-curve intersection (CCI) algorithm to use the GPU akin to what you see in the McMains paper.  Overall it seems to work really well.  We are probably getting a 20-50x improvement in performance.  Not too bad.  There are still a couple of details to clean up, but this should be the way of the future for Wildcat.

Also, I got some good messages over the weekend about a broken Windows build.  I cleaned up the VS project (and moved all of the code to a VC9 project).  So you Windows folks, please try again.  Tomorrow I am going to take a shot at surface-surface intersection.  Should be pretty easy since I can pattern off of CCI.


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