Hello, I'm new here

[smcameron]

Hi John,

I really haven't tried very hard to make cratered planets. Earthlike does have a cratering option (-c I think) but it's not very good as I haven't put much work into it. Here's a picture of a normal map that's cratered (I am not totally sure the normal maps that earthlike produces are actually correct -- my graphics engine for space nerds in space can't actually use the normal maps. I should really fix that some day.)


cratered-normal-map.png

Heightmap from earthlike should be easy, as internally it uses a cubemap of 6 square arrays of 3d vectors the magnitudes of which are --- wait for it -- heights. Just scale those magnitudes to whatever range you like and spit out grayscale pngs. I may give this a shot myself as it seems like it might be interesting.

Incidentally there are probably some easy optimizations that could speed it up greatly as it iterates over every single one of those vectors for every bump added, iirc, and it should be possible to avoid the majority of that work by figuring out for example, that an entire row of vectors is nowhere near a given bump and can thus be skipped instead of dumbly plodding through all of them whether they're needed or not.

[smcameron]

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have you had much luck in getting a good cratered planet , like Mercury or the Moon ( and rocky moons of Jupiter and Saturn)

Hi John, you asked about this some time ago... lately I have been adding normal mapping into my little home-made game engine, and so I have been playing around with craters some and have made some progress. I expect someone familiar with lunar or martian geology would find my creations to be hopelessly obvious in their fictional-ness, but nevertheless I am so far pleased with my progress, though there is always room for improvement.



This was created with earthlike.c, but using "land" images for both the "water" and "land" inputs to the program, and the version of earthlike I am using is on the "debug-normal-mapping" branch in the git repository (instructions for checking out that branch are at the top of this bug report: https://github.com/smcameron/space-n...pace/issues/79 ) (Edit: this has since been checked into the main branch so no need to checkout the debug-normal-mapping branch.)

To create that planet, the command line was:

./earthlike -B 400 -b 1 -h heightdata.png -l ~/rockslab2.png -w ~/rockslab1.png -O 0 --bumpsize 0.5 --craters 1000 -o myplanet

then to view:

./mesh_viewer -p myplanet -n normalmap

(normalmap*.png and myplanet*.png are outputs of earthlike.)

where heightdata.png is included in the repository. rockslab2.png and rockslab1.png are thin vertical strips of images of some rock (100 pixels wide by 500 pixels tall or so that have had contrast somewhat reduced and been aggressively gaussian blurred -- for whatever reason, that kind of input image seems to work the best.)
Have also had good luck using vertical strips of images of Jordanian desert, dirt, hubble mars images, etc, with the same blur and contrast reduction applied.

[miltiadesXO]

Cool stuff, welcome to the Guild!