This blog is not affiliated with our employer, Analytical Graphics, Inc., although we thank them for providing a workplace in which we were able to gain expertise in this field, and for being incredibility understanding of our book project.
Patrick and Kevin.
About Our Book
Our book, 3D Engine Design for Virtual Globes will be published by A K Peters/CRC Press in June, 2011.
Visit the website for all the details: www.virtualglobebook.com.
About the Title Bar Image
The title bar image was rendered in three passes. The first pass renders a ray casted globe to three g-buffers: the day buffer, the night buffer, and the blend buffer.
The second pass renders vector data to the day buffer using a geometry and fragment shader to render thick (pixel size greater than one), outlined, anti-aliased polylines.
In the final pass, a full screen quad uses the blend buffer to composite the day and night buffers.
Of course, there are variations and optimizations that can be used. Source code for this example is included with OpenGlobe. The day imagery and vector data is from Natural Earth, and the night imagery is from NASA Visible Earth.