Demo Earth - By: Eric Grange Date: -
Download (587 KB)∞
Earth is an experiment in atmospheric rendering: the atmosphere is rendered around a blue planet, using CPU-side raytracing to determine intensity and penumbra. By picking carefully selected samples for the raytracing, it can be done at a negligible CPU cost. The earth surface itself uses the NASA 'Blue Marble' texture (day and night, smoothly interpolated at render-time), Clementine mission data for the moon, and Yale and Hipparcos databases for the stars. An optional high-resolution dataset can be
downloaded here (3.3 MB)∞.
A small (code-wise) demo that features earth, with night and day texture maps, atmospheric effects, an orbiting moon, the sun, a stars background and optional constellation lines.
The only technical part lies with the atmospheric effect, which is raytraced on key points, and then interpolated in between. Yes, I know earth atmosphere's is much thinner, but a thicker atmosphere looks better :)
Requirements:
- Hardware accelerated graphics with OpenGL support
- multitexturing and ARB_texture_combine support for city lights (ie. recent drivers and GeForce/Radeon-class hardware)
- 64 MB video memory for high-resolution resources support (optional, and 128 MB recommended for optimal performance)
Keys and Controls:
- Mouse left click : move around your target body
- Mouse wheel : move comera closer/farther
- Mouse right click : adjust focal length
- 'E' : center and target Earth
- 'M' : center and target Moon
- '0'..'9' : adjust the speed, from paused (0) to superfast (9)
- 'C' : toggle constellation lines visibility
- 'H' : loads high-resolution resources
The high resolution resources are intended for GeForce3 and higher video cards, with 64 MB or more of video memory, they are available for download in a separate package at:
https://sourceforge.net/project/showfiles.php?group_id=29749∞
They include 4096x2048 textures for earth (night & day), 2048x1024 texture for the moon and the hipparcos star database (87000 stars, rather than the 9100 ones in the default Yale db). High-resolution mode also turns on FSAA (if available).
Resources credits and links:
