POV-Ray : Newsgroups : povray.binaries.images : POV-Earth thread : Re: POV-Earth thread Server Time: 9 Aug 2020 14:46:44 GMT
  Re: POV-Earth thread  
From: Bald Eagle
Date: 11 Jul 2020 21:55:06

My man jr and I have discussed the many aspects of this at great length, and
I've formulated a suite of files to generate the framework of the planet and
create tiles as separate include files.

Some more work needs to be done in order to create some DEM-style terrain, but
at the present time, all of the "parts" successfully work to render the planet.

The idea here is that although a huge number of tiles may be needed to render
all of Earth, the likelyhood that anyone will need to accurately and
realistically render all of the areas of Earth covered in water, ice, sand, or
forest is --- low.

So the "engine" looks for existing tile definitions, and when nothing is there
(zero data storage), a default texture is rendered.

The include files are "autonomous" in the sense that they are included to
provide content for the region they describe, and the engine need not worry
about it.

jr has worked out and written a lot of QuadTree code, so once some more
development has occurred, we'll start experimenting with tile subdivision, and
distance-based Level Of Detail (LOD).

So, a .pov file takes the number of subdivisions of each face of the QuadSphere
and uses that metric to create NxNx6 include files.  They are currently randomly
textured based on a randomly generated biome type that is defined in it include
file.   The plan for later is to scan a global image map and make a rough
assignment of tile biome type based on that.
That will essentially take care of 89% of the planet, and leave 11% of the
planet where something of interest might actually be.

Individual tiles can be created/copied, subdivided, and edited to add things
like oil platforms in the middle of the ocean, TdG on an arctic ship, or
anything else, wherever one might like.

The attached proof-of-concept image is 8*8*6 = 384 individual include files,
automatically generated, and without any user-added content.

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