Ray Casting..

hi, Im currently stuck at this problem that I have no idea on how to do it.

I’v loaded a mesh and now I’m trying to find the front facing vertices and store their information.
After that I will match it with the stroke I’v drawn. and only select the vectices that are with the stroke.
btw the stroke drawn is not just a line, it is just alot of points that forms a stroke.

I heard how to to this is to cast a ray. I checked out the theory of what it is… but I have totally no idea of how to get it implemented.

Thats why im trying to get help.

Thanks alot…

You can use a physics-engine for raycasts.

One very good, open-source, easy to use engine is Bullet.

I am currently using it and i make 3000+ raycasts each frame, at 30 Hz (plus a lot of other stuff), so lots of raycasts are feasible.