•November 10, 2015 • Leave a Comment
November 9, 2015 — For awhile now clouds have been on my mind, specifically, clouds for seamless cubemap planet textures. I have come up with a method that seems to produce passable results. Here are a couple examples:
The method begins with another method I used for generating cubemap terrain textures. That method involves sampling real terrain elevation data to programmatically create “brushes” on the fly which are then used to recursively paste and blend elevation patches onto a sphere. The key insight I had was that I could do exactly the same thing with with satellite cloud imagery — treat it as if it were elevation data, and paste and blend dynamically created “elevation” patches consisting of slightly processed and sampled grayscale cloud imagery — I didn’t even have to write any code, I just gave my existing program different data to chew on.
This by itself worked ok, but lacked the kind of “swirliness” that you see when you look at pictures of earth taken from space, as you can see below.
For this swirliness, I fell back to my other nifty program gaseous-giganticus, used for creating gas-giant planet textures. I noticed that the “swirliness” of planets like Jupiter is quite different from the swirliness of planets like Earth. I spent some time looking at this super cool real-time earth wind thing and some time playing with the noise-scale parameter of gaseous-giganticus to get a better handle on how to produce a given sort of swirliness. Here are some pictures showing the effect of various noise scale values in gaseous-giganticus.
Once I could produce some satisfactory looking grayscale cloud cubemaps, it was a simple matter to take a white image and use the cloud images as an alpha mask and composite it onto terrain images.
In my Space Nerds In Space github repository, I describe in some detail exactly how to do all this. See: How to Generated Earth-like Planet Textures.
•October 25, 2015 • Leave a Comment
October 24, 2015 — Today, over at Astronomy Picture of the Day, they have posted a nice projection of Jupiter’s cloud tops. Being an aficionado of gas giants, I could not resist slamming it onto a sphere, and making an animated gif out of it.
(you may have to hover the mouse over the little icon and right click and “View Image” — I think wordpress or maybe imgur doesn’t like hotlinking Jupiter sized gifs.)
•September 1, 2015 • Leave a Comment
August 31, 2015 — Space Nerds in Space consists of a server process, which simulates the goings on in a solar system with various planets, asteroids, spaceships, and so on, and a number of client processes which players use to interact with this simulated solar system. There’s a limit to how much stuff you can cram into this server process. It occurred to me that if there were multiple server processes potentially running on multiple computers and if players could travel between those servers, that limit might be considerably extended. So I’ve begun some experiments to see whether I can put together such a system. So far so good, though there’s still a long way to go.
•August 24, 2015 • Leave a Comment
August 23, 2015 — Here are a couple more procedurally generated gas giants made with gaseous-giganticus.
•August 16, 2015 • Leave a Comment
August 15, 2015 — Here’s Jerry Coyne’s talk about free will, or the lack thereof:
It’s nice to see someone so prominent and well spoken present what are essentially the same conclusions I’d privately reached as a college freshman, and which I’d written about before on this very blog back in 2008.
•August 15, 2015 • Leave a Comment
August 15, 2015 — Here are a few more procedurally generated gas giants made with Gaseous Giganticus, which is part of Space Nerds In Space. Imgur album is here.
•August 15, 2015 • Leave a Comment
August 15, 2015 — Just back from a short trip to Yosemite National Park with my parents. A few pictures are below, and here is the full album of 135 images of Yosemite on imgur.