Hi Guys,

As part of my project in college, I need to have a 3D beam of light go through a lens and refract. I have the beam working fine. I have hit a hurdle with the 3D thin lens.
I am quite new to processing and from my research there is no built in primitive that will allow me to draw what I need.
Can Sphere() be adjusted to give me a compressed or flatened like shape that will look like a lens.

Any help here guys would be great.

A squashed sphere will indeed produce lens-like effects, but note that it's a different physical shape than sort of classic lens described by standard optics equations.

Remembering waaaaaay back to my college physics days, the lenses we learned about in that unit were modeled as solid geometry operations involving purely spherical surfaces; e.g. the intersection of two spheres to make a standard convex-convex lens, the disjunction of a couple of spheres with a cylinder to make a concave-concave lens, et cetera.

If you squash a sphere, you'll approximate a true convex-convex lens, but it won't be the same because the degree of curvature will vary smoothly across the face of the lens, from a small value in the middle to a high value at the edges.  With a real lens, the curvature at any point is constant until you get to the sharp edges, where the curvature is mathematically undefined.

I really don't know how you'd draw lenses in this fashion using Processing, but then, I've never done any 3-d stuff in processing.  I do wonder, though, whether you might be better off with a different tool like POVRay or something, which not only has built-in geometry operations like union and difference, but is also pretty good at modeling light propagation.

Perhaps a simple arc?

Code:

strokeWeight(20);
arc(50, 55, 50, 50, 0, PI/2);
 

Oh, well if you're using the right lens math in the background, then who cares if the visualization is just an approximation of a true lens shape?  I mean, the light rays are still going to bend the correct amounts and directions (assuming you get your math right).

That being the case, I'd totally go with a squashed sphere for now because that will be fast and easy.  Use it as a placeholder, and if you finish the rest of the project (the important pieces of functionality, that is) with some time left over, you can dig into drawing a real lens shape.