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The Alps in three dimensions

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After introducing the Landsat mosaic of Germany and the Alps i also produced a shading compensated version. Here are a few new 3d renderings created using that image.

In contrast to my earlier views of the Alps these show more uniform and consistent coloring. They also make use of OpenStreetMap waterbody data for rendering the lakes. In previeous views with distinct rendering of lakes i used a mesh based model – i now moved to a meshless geometry representation like also used for the terrain which scales much better and allows rendering large areas with a small memory footprint.

Colors of the Landsat mosaic also match the Green Marble image fairly closely as can be seen in the following comparison.

As i frequently explain these views try to give a realistic impression of the earth except for one important point – that there are no clouds and the atmosphere density is strongly reduced giving an impression as you would have it at close distance but with a different perspective. Key to creating a realistic and appealing image is a consistent appearance, things our brain tells us are impossible are irritating and disrupting and therefore need to be avoided. When looking at a 3d view lacking shadows or reflections on water surfaces we might not be consciously aware of these deficits but intuitively we realize something is not right. In this regard the atmosphere creates something of a dilemma. The reason is skylight. Normally illumination from the sky contributes significantly to the lighting in shadow areas. Skylight however comes from the atmosphere and if the atmosphere density is strongly reduced you would also reduce the skylight intensity. Or you keep a skylight intensity from a realistic atmosphere and combine it with a lower atmosphere density in direct appearance. In either case there is some level of inconsistency involved.

Normally i work with a fairly low amount of skylight leading to strong contrasts that help visualizing the terrain. In these views skylight is somewhat stronger so contrasts are not that extreme and appearance in total more closely resembles the impression you’d get on the ground.

The two first views are available as prints and for licensing on services.imagico.de. The last one i put up under CC license on the Views of the Earth in a size of 4000×3000 pixel.

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