We’ve released version 2.0 of
our C++ library for real-time, physically-based rendering of the sky, 3D
volumetric clouds, and weather effects. This new release features a new
type of cloud - stratocumulus - rendered used GPU ray-casting; this new
cloud type is featured in the images above.
With GPU ray-casting, truly 3D, volumetric clouds of very high densities
become possible, with per-pixel lighting. A fragment program casts rays
from the camera through each fragment of the cloud layer’s bounding
volume, compositing together color, opacity, and lighting information as
it passes through the clouds. The clouds themselves are stored as 3D
textures, with an ancillary 3D noise texture used to provide fractal
These new cloud types augment SilverLining’s existing cumulus cloud
types (cumulus congestus, cumulus mediocris, and cumulonimbus) which
render the underlying volume data using billboard splatting. Splatted
clouds are featured in the SilverLining
Demo and our
We provide sample integration code for OpenGL 1.4, OpenGL 3.2, DirectX
9, DirectX 10, and DirectX 11, as well as for the Ogre, OpenSceneGraph,
SceniX, and Carmenta engines. Visit Sundog’s
website for a free evaluation SDK and more
information, and feedback is welcome!
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great! you really have to see it in motion to see how good it really is
I find tho.
Nice work Frank. It feels neat when you flood the scene with clouds, it
gives a whole new perspective. On the performance side, I did notice a
drop in FPS when I decorated the skies like that. Have you incorporated
any performance enhancements yet? For instance, do you stop traversing
through the volume once the opacity for the pixel reaches 1.0? I think
(out of ignorance) that if one cloud fills up my screen and runs well, I
figure a sky of them should perform at almost the same speeds
(especially if you can’t see them).
One last thing. You say the clouds are stored as 3d textures, but I
presume they are procedurally generated? I noticed some clouds looked
the same and that statement makes me wonder now.