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hacking honolulu

Posted by lycium 
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avatar hacking honolulu
November 15, 2007 04:27AM
well, today's exam (apm311 / cos332) sucked, and since ilan mentioned implicit surfaces in the cos340 forum i thought i'd resurrect the dataset we worked with, elevation data from honolulu, and throw my new rendering system at it.

it looks quite ok with just the skylight (based on http://www.cs.utah.edu/vissim/papers/sunsky/sunsky.pdf), but i want to add direct sunlight too, using the measured per-wavelength-response data i have, and some water. also i doubt honolulu is as pale as my skin is.

avatar Re: hacking honolulu
November 15, 2007 05:59AM
added something vaguely resembling water, made the land (too) green, still no sunlight.

avatar Re: hacking honolulu
November 15, 2007 06:50AM
Impressive stuff dude! thumbs up
avatar Re: hacking honolulu
November 15, 2007 06:54AM
avatar Re: hacking honolulu
November 15, 2007 09:10AM
hacking at it again, this time some ice. there are a number of issues with this pic, most notably the artifacts due to bilinear interpolation that causes a faceted look; going to switch to bicubic filtering (see the difference at http://en.wikipedia.org/wiki/Bicubic_interpolation) and re-render it.

ah, found this nice link on the wikipedia article which describes exactly what i'll be doing: http://www.geovista.psu.edu/sites/geocomp99/Gc99/082/gc_082.htm



edit: here's the same data, but using bicubic interpolation:

Re: hacking honolulu
November 15, 2007 09:16AM
that's amazing!
avatar Re: hacking honolulu
November 15, 2007 09:21AM
thanks smiling smiley still needs:

0. better heightmap interpolation (working on it now)
1. to work in 32bit mode (so i can show the program to other people)
2. sunlight
3. clouds and real atmospheric simulation
4. vegetation, or maybe some polar bears...
avatar Re: hacking honolulu
November 15, 2007 09:29AM
I like the very first very white one the most.

 
  ,= ,-_-. =.
 ((_/)o o(\_))
  `-'(. .)`-'
      \_/
http://ilanpillemer.com
Entia non sunt multiplicanda praeter necessitatem
avatar Re: hacking honolulu
November 15, 2007 09:38AM
that's racist!


*ahem* anyway, i got the bicubic interpolation working, too bad it's rendering 15 times slower.
avatar Re: hacking honolulu
November 15, 2007 09:44AM
Do you do all your rendering using your own 3d engine? No blender projects?
avatar Re: hacking honolulu
November 15, 2007 09:50AM
yup, and i'll post an exe once i fix the 64bit-only bugs. usually i make everything i render procedurally (equations, functions, filters, ...) in code, as is the case with my whole deviant art gallery, but in this case i'm messing around with a heightmap we were given in cos340 earlier this year.

the opengl thingy i did with this is here: http://www.fractographer.com/propaganda/heightmap_res.zip
avatar Re: hacking honolulu
November 15, 2007 10:06AM
ilanpillemer Wrote:
-------------------------------------------------------
> I like the very first very indian one the most.

then it's time to visit mars! http://astrogeology.usgs.gov/Teams/Geomatics/photogrammetry/topography_mars.html
avatar Re: hacking honolulu
November 15, 2007 10:08AM
Quote

thanks still needs:

0. better heightmap interpolation (working on it now)
1. to work in 32bit mode (so i can show the program to other people)
2. sunlight
3. clouds and real atmospheric simulation
4. vegetation, or maybe some polar bears...
/

5. Waves and ripples in the water like substance

--
"Knowledge has much better uses than self-pity and superiority"
avatar Re: hacking honolulu
November 15, 2007 10:16AM
yeah true, i even have a good model for that (turbulence function / fractional brownian motion) but it's a bit of a mission to implement. in lieu of this i've modelled the surface as being somewhat rough, which is what causes the glossy reflection in the second picture.

too bad the ocean is still an ironing board :| well, it's gonna go just now when i visit mars. the elevation data is a bit crazy though, for example:

222.135498 276.973145 332.797302 371.906891 378.618622 352.646606 303.663879 240.784241 169.135757 90.805214 5.693018 -86.419006 -187.922653 -299.617737 -417.056732 -535.627869 -651.623657 -762.726013 -867.592712 -963.531677 -1048.488525 -1117.031128 -1166.434326 -1200.080811 -1220.082031 -1231.835693 -1237.454224 -1241.709351 -1246.300049 -1252.034058 -1257.955811 -1263.162354 -1268.062988 -1272.953491 -1278.757568 -1286.148926 -1295.865601 -1303.539917 -1301.344238 -1293.473389 -1277.157227 -1256.832031 -1234.098755 -1214.135986 -1196.614502 -1184.824463 -1174.162598 -1164.864014 -1157.636230 -1152.661377 -1150.402222 -1150.462036 -1156.408081 -1165.505493 -1178.903931 -1191.424194 -1200.755615 -1200.632080 -1192.979736 -1173.812500 -1150.363403 -1123.043091 -1093.006836 -1058.973511 -1017.941162 -971.028137 -917.326599 -858.475708 -794.897461 -730.069885 -666.330200 -605.483826 -547.056763 -490.615540 -436.034119 -384.729919 -338.932373 -301.354187 -273.681946 -255.754654 -246.720825 -242.998077 -241.629120 -241.101257 -240.277664 -238.850922 -237.078903 -235.743942 -236.204010 -239.719635 -246.569336 -256.584290 -269.321899 -284.141327 -300.667236 -318.301239 -336.624969 -355.414551 -374.829956 -395.435242 -415.811157 -433.606506 -449.961639 -465.529755 -479.553802 -491.546082 -500.968903 -508.714844 -515.459045 -521.055359 -524.808044 -526.933411 -527.417053 -525.476929 -521.654541 -514.432678 -505.408020 -494.199768 -481.013641 -465.982086 -449.746338 -433.094757 -417.512695 -403.163513 -391.410492 -382.206116 -375.489868 -370.652100 -366.563599 -360.736450 -352.667419 -339.873352 -323.924316 -305.641449 -288.148926 -272.545624 -263.288086 -258.339783 -258.040649 -261.396118 -267.413635 -273.751038 -274.990387 -277.560760 -282.127930 -284.440979 -281.151123 -269.643829 -249.109482 -221.198669 -189.706085 -159.313461 -133.965561 -115.783592 -104.766113 -99.860390 -100.246666 -103.580772 -106.835747 -109.054710 -109.555779 -108.456200 -107.181213 -106.329575 -104.700676 -102.025230 -98.876610 -95.490211 -92.022202 -88.237930 -84.374130 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000
-340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 -340282265508890445205022487695511781376.000000 4433.406738 4432.241699 4431.725586 4432.038574 4431.580566 4429.462402 4427.045410 4424.989258 4423.709473 4422.617188 4420.937988 4418.899902 4416.552734 4413.921387 4410.864746 4407.216309 4403.620605 4400.718262 4398.202148 4396.134766 4394.804199 4394.182617 4393.983887 4393.982910 4394.061523 4394.131836 4394.178711 4394.241211 4394.327637 4394.424316 4394.552246 4394.705566
avatar Re: hacking honolulu
November 15, 2007 12:48PM
Excellent article - the Wikipedia one re DEM's - thanks!
iva
Re: hacking honolulu
November 15, 2007 12:57PM
ah this threads given me flashbacks of the course, was really a great subject and alot of us couldna' done it without ya T smiling smiley

(Thankfully only 1 exam left this year!)
avatar Re: hacking honolulu
November 15, 2007 09:20PM
aww fanks iva smileys with beer
avatar Re: hacking honolulu
November 16, 2007 10:35AM
i found some ~200mb elevation map of the earth (going to get nasa's 3gb dataset of surface colour + altitude + clouds next month), rendered africa:

Re: hacking honolulu
November 16, 2007 11:02AM
wow!

just needs some green.
avatar Re: hacking honolulu
November 16, 2007 11:24AM
I have made that my background.

spinning smiley sticking its tongue out

 
  ,= ,-_-. =.
 ((_/)o o(\_))
  `-'(. .)`-'
      \_/
http://ilanpillemer.com
Entia non sunt multiplicanda praeter necessitatem
avatar Re: hacking honolulu
November 16, 2007 11:26AM
and some holes for all the oil drilling and gold/diamons mining. Also need some blood over mugabe's country...
avatar Re: hacking honolulu
November 16, 2007 12:13PM
hehehe, that could be fun smiling smiley i still need to code in rgb -> wavelength spectrum conversion though, it's a bit tricky...

actually, about the holes, the surface of the earth without water looks pretty... surprising. i'm going to render this thing BIG overnight:



check the "stretch marks" (striations) around africa, and the extremely deep bits around australia. i left out america... who cares right? tongue sticking out smiley

after cos301 on monday i'll put this data on a sphere, use real surface colours and maybe try to hack some atmospheric scattering. then once i get the nasa dataset i'll go hardcore with it, and render a little animation where the camera flies from space down to new zealand winking smiley
avatar Re: hacking honolulu
November 16, 2007 11:27PM
here's the large render (actually the original is 15360x9600 res): http://lyc.deviantart.com/art/earth-s-surface-69943493
Re: hacking honolulu
November 17, 2007 10:35PM
Bloody amazing Lycium.
avatar Re: hacking honolulu
November 17, 2007 11:42PM
thanks mate!
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