The big new feature is improved stratus clouds, thanks largely to feedback from our friends at Vizerra. For nimbostratus clouds, you’ll now see some real 3D depth at the tops of the clouds – there is now some actual geometry to nimbostratus, and not just textured planes. This geometry is computed on the GPU using a Cg vertex program for OpenGL users, and HLSL for DirectX. We also made some improvements to “geocentric mode” and the rendering of the atmosphere from space.
Even better are the new “stratus” cloud types. Unlike the existing nimbostratus that stretched infinitely to the horizon, the stratus cloud may be localized, and honors the size and position specified when creating the cloud layer. This means you can have stratus clouds with a defined edge to them, and create scenes like the one below where a bank of clouds is starting to roll in from the horizon.
Version 1.91 also includes improvements for users with whole-Earth simulators using “geocentric mode” to render the atmosphere from space. You’ll find the rendering of the atmospheric limb is now much more robust, and will render with the proper size and orientation under any viewing angle. We also smoothed out the transition as you enter the atmosphere, and added a config setting you can use if you’re in a system where the Y axis points North instead of the Z axis.
A simple infrared sensor mode was also added – see Atmosphere::SetInfraRedMode() for “white-hot” IR scenes with black skies and clouds, and a white sun.
As always, the file releasenotes.txt in the SDK contains the complete list of changes in this new version, and let me know if you run into any trouble.
Best wishes to you all this holiday season. .