rayhittest - intersections with raycasting

[Aaron Auty]

I am trying to use rayhittest() in a snippet to test for intersections from a primitive to an arbitrary location. (A camera, a light etc)

I have an example that works in SOPs in my .hip using intersect, however I need something that works at render-time.

I have tried adding a scope to self, however, I am not sure if my syntax is correct. I have something like;

dist = rayhittest(origin, ray, 0.05, 'scope', 'self');

 

If I bind dist to a hard coded value, I can see that something is coming out of the snippet.

Any pointers? Any easier ways to do shader based intersections?

 

Hip file attached

Cheers,

Aaron.

rayPigs.hipnc

[davpe]

well this is a bit odd what you doing. not sure what the result should be. technically, you cannot evaluate an intersection with a point in space as there is no surface area to be intersected. in sops it gives you some result but I haven't found it meaningful in any way. anyways, if you want to use intersect in shader you can use the same Intersect VOP as you have in SOPs.