To determine how large a sceneвЂ™s texture files need to be, I start with the final rendering size and work backwards.

(If my math is right, that yields a resolution of about 3.5 pixels per mile at the equator.) Individual tiles, each measuring 90 degrees latitude by 90 degrees longitude, are also available at the same size, 21,600 by 10,800 pixels. The main composites areВ 21,600 by 10,800 pixels and, as tiffs, clock in at over 900MB apiece. Earth surface image downloaded from NASAвЂ™s Blue Marble website. Other images, available at the same scale and resolution, depictВ topography (altitude), bathymetry (ocean depths), city lights, and cloud cover. The polar icecaps advance and retreat, and vegetation morphs from green to brown and back again. Most are surface image composites representing each month of the year. NASAвЂ™s Blue Marble web page, part of its Visible Earth catalog, includes many high-resolution images of the EarthвЂ™s surface. Which makes Terragen aВ killer app for building planets.ДЇirst, weвЂ™ll call on NASA to gather some of the parts weвЂ™ll need. Most often the point of viewВ is at ground level, but it also can be placed out in space. Among its many strengths is the ability to render natural-looking surfaces вЂ“ land and water вЂ“ and atmospheres and clouds. Terragen is a specialized 3D application used primarily to create landscapes. So when given the opportunity to try it with Terragen, I was curious to see how it would work out. The results can be convincing, but the process isВ involved вЂ“ requiring several concentric 3D spheres with various types of surfaces and opacity to replicate landmass, ocean, atmosphere, and clouds. IвЂ™ve put together and rendered orbital views of Earth before, most recently in Autodesk Maya. A recent project required a view of the South Pacific as seen from Earth orbit.

Mount and blade use pixel shaders