Viewed from space, the Earth generally does not appear very shiny, since most of the natural surfaces have low albedo and reflectance, with the exception of water. The ocean-covered parts of the Earth glint from fairly weakly to very strongly depending on various factors. However, even though 70% of the Earth's surface is covered with water. clouds also cover about 70% of the total land and water area. So the only time specular highlights are visible is when they peer through a cloudless sky, with still water (such as ponds and lakes) acting like polished mirrors giving off the strongest specular sun glints.
To recreate specular highlights on a CG Earth, a specular control map is needed. In addition, some noise should be added to simulate the ocean waves which breaks up the specular highlight into a glossy appearance from far.
The following are work-in-progress shots dated 27 Sept 2011:
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| The use of a specular map allows the rivers to glint in the Sun |
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| Water is the most intensely specularly reflective material occuring naturally |
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| The specular highlights for rivers and lakes are built into the land surface shader using a VEX network. As such, these bodies of water need to be depicted and aligned in the color, specular and displacement maps |
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| Turbulent noise nodes are used to build the specularity of the ocean surface shader in a VEX network. A land/water mask is used to inform the shader where the ocean noise is needed |
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