Re: [Algorithms] Problem with Woo's "Fast Ray-Box Intersection"

[Andrew H. <an...@co...>]

I spent a while optimizing this test.
Generally you're going to test a ray against many AABBs.
Instead of doing the divides each time you test a box, just do them once,
and multiply instead.  This is much quicker.
Watch out for axis aligned rays.  One or two of the deltas can be zero, but
luckily this is a special case and you don't even need to do the divide.
For example, if delta.x==0, all you want is: min.x <= origin.x <= max.x.
I do this by swapping to a slower routine if one or more of the delta
components is zero.

Andrew.