Renderdog wrote:
> 
> Wow, those are impressive images! I've never seen an image such as your
> Himalaya image, where you can see the curvature of the earth and the
> non-smoothness of the surface (mountains). It would make a great backdrop
> for an animation. I like the atmosphere also.

Thanks.

> How was the earth's surface modeled, as a triangle mesh or some other
> method?

A mesh would have taken way too much memory.  Remember the whole earth
with 1km resolution in a regular lat/lon mesh would mean about 1.8 billion
triangles.  A 45x45 degree tile still has 29 million vertices which (with
normal vectors) would use about 700 Mb (not counting the face and normal
indices!)

I used an isosurface with an image_map pigment function defining the
height of the terrain.  This only uses 2 byte per pixel and nothing more
(about 56 Mb per tile for the height data). 

> Another way to show the depths of the seas would be to color-code a smooth
> surface (deeper waters darker blue).

I have also made test with color depending on the height and without the
image_map texture.  Will see if i can post some sample for that too.

> How long did it take to render? I've always been impressed with how fast
> POV-Ray can render huge files.

The whole image at 6400x4800 took about 1-2 days.  The speed of rendering
an isosurface does not much depend on the detail level (although more
detailed data of course requires higher max_gradient).  

Christoph

-- 
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Last updated 28 Feb. 2003 _____./\/^>_*_<^\/\.______

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