Christopher James Huff wrote:

> A sphere primitive for the planet. As you get closer, a mesh of the area
> visible from the ship...
>
The switch between these two may be ugly. Mountains pop up suddenly. 
But using a 200k mesh may be fine. 

> a few hundred thousand triangles, maybe a million. 
>
Yes, one million is enough if you see the whole planet. 
A few hundret thousand is okay for 320x240 only. 

> Once you get close to the canyon, switch to a high level of
> detail mesh, the detail will probably require a million or so. 
>
That was what I actually expected to read... However:

One million for the canyon is far too few. The problem is that 
in mid-ragne and in far background, it is okay but the foreground 
looks real ugly. 
(Solution: mixed-grid mesh per frame, but we're here because we wanted 
to avoid it, right? Other solutions? (beyond isosurface))

Here is the actual problem. 

> You could set things up so
> you have one bigger mesh with variable amounts of detail, highest in the
> canyon...simpler 
>
Well, would be feasible if 1e6 triangles were enough for the canyon. 

> but less efficient, but nowhere near as bad as your
> idea of using a full-resolution mesh of an entire freaking planet.
> That is just wasteful on current systems, even if you have the RAM for
> it.
> 
The only feasible alternative I've seen is Christoph's proposal using an 
isosurface image map. 

Wolfgang

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