Ray Sop And Interpolated Normals?

[Vormav]

Hey. New guy around here, so go easy on me.

I'm in the process of writing a series of tutorials, and I've chosen to use Houdini to create some of the visual raytracing charts for this (because Houdini makes it very easy ). So far, this is working great: I'm using a Ray SOP to cast one point of a curve onto my geometry, and from there I have a few nodes that move the start and end points of another curve in place to form a reflected line (with an arrow on the end), making for a pretty accurate raytracing demo.

But there's one little thing I can't quite figure out: how to get the interpolated normals for the Ray SOP intersection. As far as I can tell, the ray sop can only return the uninterpolated normals. Now, I'm sure that I could linearly interpolate them myself, with a bit of work. But before I go and potentially waste time on that, I just want to check and see whether or not there's already an option built in for getting the interpolated normals of the ray sop intersection. Yes, no?

(not directly modelling related, but it still falls under SOPs)

Also, while I'm at it, I might as well ask; are there any nice and quick ways to rotate objects to be aligned with a certain normal vector? I suppose you might actually need a basis vector to be able to pull that off...?

Thanks

[sibarrick]

It won't do exact interpolation but you could use attribute transfer to copy the normals across this will allow you to sample more than one normal and average them.

As for the second question check out the rivet object. Or there are some otls on exchange that do this sort of thing.