alt.hn

1/20/2026 at 3:28:01 AM

Flying with Photons: Rendering Novel Views of Propagating Light

 https://anaghmalik.com/FlyingWithPhotons/

by pillars

1/23/2026 at 3:25:24 PM

This is an improvement on a older technique: https://www.reddit.com/r/educationalgifs/comments/6wqwh1/lig...

or see https://en.wikipedia.org/wiki/Femto-photography

by nlitsme

1/23/2026 at 3:50:13 PM

Also a technique used all over the place for studying how molecules react to light. Probe it with as short of a laser pulse you can afford to buy and measure the light emitted by it some time later. My wife has been doing this basic technique for years studying things like molecules to generate fuels from sunlight. (Or was until solar energy funding as practically eliminated last year, now it's studying other things using similar techniques)

by rtkwe

1/23/2026 at 6:42:03 PM

So... why? If you care about accurate visualization of propogation of light through a complex scene, why not just do a full wave simulation? There are multiple, well studied techniques (Finite Difference Time Domain, Finite Difference Frequency Domain, Finite Element, Method of Moments...). These will give you what the light will 'actually'[1] do, not a guess based off some small sample of training data.

[1] Like with all modeling, there are of course assumptions and approximations. Different techniques have different strengths and limits. Still, these are all well vetted, studied and used by people who care about accuracy.

by NRHuntoon

1/23/2026 at 6:45:45 PM

Well, this does the actual measurement. Measurement is how deviations from theory are discovered.

by nlitsme

1/23/2026 at 4:12:20 PM

It's not real. It's rendering with some smart hacks.

by iberator

1/23/2026 at 7:25:25 PM

It's measuring light through multiple samples, and then aggregating them together. Not all that different from a long exposure photograph.

by zeckalpha

1/23/2026 at 6:44:32 PM

Please define 'real'.

by nlitsme

1/27/2026 at 10:44:05 PM

Single shot from single place instead scanning it for ALL DAY and claiming it's real time etc haha

by iberator

1/23/2026 at 5:12:05 PM

Um... "rendering" is in the title, and implies that no one is literally "flying with photons". What part did you believe was "real"?

by IAmBroom