Sundog Software announced that it has released a new version of SilverLining, its C++ class library for real-time visual simulation and rendering of the sky and 3D clouds. SilverLining 1.06's cloud and sky rendering SDK is available for Windows projects that use either OpenGL or DirectX 9.
New features in version 1.06 include support for Visual C++ 6, 7, and 8, a clouds-only mode that won't touch the application's back or depth buffers prior to cloud rendering, improved lighting of stratus and cirrus clouds, and some minor bug-fixes. The SilverLining SDK comes with sample code for both OpenGL and DirectX9 under Visual Studio, and complete API documentation. An interactive demo of version 1.06, along with a free evaluation copy of the complete 1.06 SDK, is available at Sundog's website
SilverLining's software libraries offer physically-based simulation of the sky at any time and any location on Earth, modeling the scattering of light through the atmosphere and the astronomical positions of the sun, moon, stars, and visible planets. Direct and scattered sunlight and moonlight illuminate 3D cumulus clouds, including cumulonimbus thunderheads complete with self-illuminating lighting effects.
The resulting scene is tone-mapped to represent the human perception of the high dynamic range of outdoor lighting conditions; this tone mapped light may be used by your software to accurately illuminate your nighttime and daytime scenes. In addition to real-time 3D cumulus clouds (which may be flown through and cast shadows), SilverLining also models stratus, cirrus, and broken stratus cloud decks.
SilverLining's 3D clouds are procedurally generated, based on a cellular automata model of cloud growth. This leads to a variety of individual clouds throughout the sky. Real-time performance requirements are realized through extensive use of vertex shaders to offload the physical simulation and some geometric calculations to the system's graphics processing unit.