
Here's my first attempt at procedurally generated cloud rendering in XNA. It's not much, but it's still a work in progress. The frame rate is low because my computer doesn't handle screen recording software very well. The clouds render at about 110 frames per second at 1280x720 resolution on an integrated ATI Radeon HD Mobility 3200 (ie complete crap video card). The cloud texture is generated by layering 7 octaves of noise of varying dimensions, each animated at a slightly different rate. The texture is mapped onto a hemispherical skydome with texture coordinates calculated by finding the x,y coordinates of the intersection between a ray cast from the observation point and an infinite plane positioned at the very top of the hemisphere. The observation point was calculated by determining the viewing angle of the most distantly visible clouds on a planet with radius 6378km and a cloud elevation of 10km. Thus, the most distantly visible clouds on the skydome are approximately the same relative distance as clouds you would see on the horizon on earth. Obviously this is just an approximation since the atmosphere is spherical in real life. However, the most distant visible clouds are approximately 190km away. A 190km slice of the top of the atmosphere is very nearly planar. The clouds look very flat. I know there are ray marching algorithms to simulate cloud scattering and stuff, but I'm rendering this on a very, very slow GPU. I'm looking for ways to improve visual <b>...</b>
clouds
procedural
generation
dynamic
XNA
The
Ghanes