Sierpinksi Triangle: http://zenphoton.com/#AAQAAkACAAEgXgB8AaYA2wJdANlWUlUCXgDZAg...

This was created by someone the last time this was on HN: https://news.ycombinator.com/item?id=5983421

absolutely stunning

With a bit of imagination, you can create scenes that look like they belong in a movie. This thing is wonderful

http://zenphoton.com/#AAQAAkACAAEgcAAOAdEA6wHRAVVjUiUB0QDsAi...

It would be awesome to have a little blog post about why and how, this is very cool tech! I'm lazy I don't want to go read the code, I want a beautiful and clear explanation with pictures

And about the what. What exactly am I looking at? All I can tell is it has something to do with the physics of light. What assumptions are made? What models are used?

Clever and pretty. Is it possible to add an "absorb" slider to the walls? I'm having trouble making some of the effects I'm trying for.

Try decreasing the reflectivity to zero and transmissivity to max.

I like how having a lot of random stuff ends up making some natural-looking textures: http://zenphoton.com/#AAQAAkACAAEgdwAeAAsAKgArABMA/wAASgH9AF...

I wish there was a "best of" for this. I don't have the arts enough to make anything visually pleasing and would love to see the results of those that do.

Artistic interpretation [1] of the Triforce:

http://zenphoton.com/#AAQAAkACAAEgagAHAAABegQqAXgA/wABFwGJAg...

[1]: Have no right calling myself an artist of any sort, especially when I can't draw straight lines.

I particularly like the "exposure" slider on the righthand side. That's a neat UI element I intend to borrow.

Fantastic! I particularly like encoding the state in the URL - makes it very easy to share good designs you've built.

Am I going mad or is this a re-submission?

It is a re-submission: https://news.ycombinator.com/item?id=5983421

The model doesn't seem precise - there is no light diffraction. See http://en.wikipedia.org/wiki/Kirchhoff%27s_diffraction_formu...

It seems like this effect could be got much more efficiently using block lighting. you could get the gradients by storing the light's strength at each vertex. This way you would be tracing only two rays per line

That doesn't provide a way to simulate reflectivity and transparency.

My first reaction was to try the double-slit experiment, but unfortunately there was no interference pattern. Beautiful none the less. (Ok, a little less.)

That's not surprising. The double-slit experiment was used to prove the wave behavior of the light. Ray tracing simulates the photon/ray behavior.

Very nice, although it took me a few minutes to figure out how it works.

I wish you could save a high resolution PNG.

I dont understand what's going on ...

It's an interactive raytracing demonstration. Draw on it, and watch it simulate light diffusion, reflection, and transmission. It's pretty straightforward, actually.

Add refraction, I want to make a laser.

Why reboot your computer when you can just load this demo and up the settings!?!