I saw this a while ago so it might not be totally related, but Sebastian Lague did a video on atmospheres for his planet generation experiment which was also very entertaining to watch [1].
There's something particularly entertaining on developing visuals and watching them come a reality — I hope at some point be able to experiment in this field.
For me the most amazing thing about Sebastian Lague is how the youtube algorithm can screw you up. He used to do millions of view on his videos, and now he barely makes half a million. Well it might also be because of covid, and everyone at home getting interesting in random stuff.
Incredible what mobile phones and browsers can do nowadays. I remember implementing this paper from 1993 (the absolutely OG for this topic and very readable): “Display of The Earth Taking into Account Atmospheric Scattering” by Nishita et al: https://www.researchgate.net/publication/2933032_Display_of_...
In another comment I recalled reading a paper while implementing Rayleigh and Mie scattering a while back...this was definitely it!
Getting it working was a "holy shit, we can actually model this complex real-world phenomenon pretty well with a few relatively simple calculations" moment. I went from a static blue skybox to a full day-night cycle just like that.
Love a good graphics writeup - I've been working on similar things for my procedural space/planet generator. The cool thing with atmospheric scattering is you can combine it with volumetric cloud rendering and get amazing sunsets & sky scenes
I've thought before about trying to render skies on the web as a series of gradients overlaid on top of one another. I expect I could have had some level of success and gotten some mediocre results, but it would be nothing compared to what you've created.
Thank you so much for sharing this; it's inspirational, must have taken you a very long time to put together, and I'm blown away by your results.
I implemented Rayleigh and Mie scattering for a game engine once (my own, hobbyist thing). It was pretty crazy to see a quite good sunset/sunrise cycle from those alone. IIRC even the sun itself popped out of that somehow.
I was using XNA (Microsoft's C# gamedev platform) and following Riemer's excellent series of tutorials, which have been preserved here[0], but I don't see anything about scattering. I might have gotten that bit from somewhere else. I do recall reading papers with math equations.
I love the scale that FAQs for things like this provide, as well as the variety of questions.
Q: How many objects are there in SpaceEngine?
A: The entire Hipparcos catalog of stars, all known extrasolar planets, over ten thousand galaxies, most objects in the solar system, which adds up to 130,000 things. In addition, more galaxies and star systems than exist in reality in all of the observable universe.
Q: How can a water planet be hot?
A: Water in the upper atmosphere is in the form of hot vapor, but farther down it smoothly transitions into a liquid state under high pressure. Even deeper it turns into a solid state called ice VII.
It's fantastic software that's been around for many years, and has exquisite attention to detail on this and many other topics; this article also reminded me of it!
Also given this is MIT licensed, the skybox for my game is a solved problem! All I need is that render where the sun traverses the sky since perspective will be fixed. This allows me to extend it for the variation of the Sun’s angle through the year with sinusoidal periodicity.
Scattering has long been key to making realistic looking rendered images. One of my favorite papers: http://www.graphics.stanford.edu/papers/bssrdf/bssrdf.pdf
which I think is the first time I learned that rendering milk is a tricky problem.
This is hugely relevant to my interests. In my spare time I've been building a planetarium/star map app (iOS / Vision Pro) and atmospheric scattering is something that has been on my todo list for awhile. This is definitely above and beyond what I'm going for atmosphere-wise but still amazing to see. Thanks to Maxime for this write up!
I wonder how this relates to the Perez All-Weather and Preetham sky models. Not an expert about that but I managed to implement those in the past and it was quite a fun project!
Oh these are gorgeous. And I’m partial to the kind of things that are based on physics models as opposed to the techniques based on graphics hacks (stacked gradients etc.).
There's something particularly entertaining on developing visuals and watching them come a reality — I hope at some point be able to experiment in this field.
[1] https://www.youtube.com/watch?v=DxfEbulyFcY
Getting it working was a "holy shit, we can actually model this complex real-world phenomenon pretty well with a few relatively simple calculations" moment. I went from a static blue skybox to a full day-night cycle just like that.
https://www.threads.com/@mrsharpoblunto/post/DVS4wfYiG8f?xmt... https://www.threads.com/@mrsharpoblunto/post/C6Vc-S1O9mX?xmt... https://www.threads.com/@mrsharpoblunto/post/C6apksDRa8q?xmt...
I've thought before about trying to render skies on the web as a series of gradients overlaid on top of one another. I expect I could have had some level of success and gotten some mediocre results, but it would be nothing compared to what you've created.
Thank you so much for sharing this; it's inspirational, must have taken you a very long time to put together, and I'm blown away by your results.
I was using XNA (Microsoft's C# gamedev platform) and following Riemer's excellent series of tutorials, which have been preserved here[0], but I don't see anything about scattering. I might have gotten that bit from somewhere else. I do recall reading papers with math equations.
[0] https://github.com/SimonDarksideJ/XNAGameStudio/wiki/Riemers...
https://spaceengine.org/
Q: How many objects are there in SpaceEngine?
A: The entire Hipparcos catalog of stars, all known extrasolar planets, over ten thousand galaxies, most objects in the solar system, which adds up to 130,000 things. In addition, more galaxies and star systems than exist in reality in all of the observable universe.
Q: How can a water planet be hot?
A: Water in the upper atmosphere is in the form of hot vapor, but farther down it smoothly transitions into a liquid state under high pressure. Even deeper it turns into a solid state called ice VII.
Q: How do I move?
Use WASD keys.
Also given this is MIT licensed, the skybox for my game is a solved problem! All I need is that render where the sun traverses the sky since perspective will be fixed. This allows me to extend it for the variation of the Sun’s angle through the year with sinusoidal periodicity.
https://github.com/jscanvic/SkySim
Flat earth version for comparison would be fun.