Le 06/12/2013 23:16, David Given nous fit lire :
> On 06/12/13 22:11, David Given wrote:
> [...]
>> One day someone's going to come up with a way of storing efficient,
>> interpolatable spherical heightmap data without the distortion involved
>> in forcing it into a 2D matrix...
> 
> The Usenet effect strikes again --- as soon as I post, I stumble across
> the answer!
> 
> http://en.wikipedia.org/wiki/Quadrilateralized_spherical_cube
> 
> However I doubt Povray's going to get a COBE sky cube spherical
> heightfield primitive any time soon, so it doesn't actually help me much.
> 
Can work for colours, but I wonder if the bins can be elevated or buried
without breaking everything.

It seems fine for painting the sphere, but modification of the shape,
i'm not sure.

But the idea is nice to generate a mesh of a sphere, yet the last
external link is saying that an icosahedron is better than a cube. (but
less easier to serialise the points)

I like it when the resolution goes down to use 31 bits... with just one
byte per pixel, you need just about 2GBytes and that's only for the a
gif-like planet at a level of 14, which still make the side of a bin
about 600m long for the Earth.
You cannot even have individual house or roads.
To spot/draw a car (as a pixel or two), a level of 22 is needed...
(reach a resolution of 2.4 m)
Either 16GBytes of black & white (fax mod), or 128GB for a gif-like.

It might be interesting for a displaying engine (with clipping of the
view), but seems not adapted to the way povray handles the texture so far.

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