Norman Vine writes:

 > but IMHO what is needed are "imposter tiles"
 > 
 > "imposters" are where you use a 'texture only" substitute
 > for the geometry that are computed on the fly 'often enough'
 > This is 'radical' LOD but in our case the tiles out on the 
 > boundary are really just 'little slivers' and there is no need for 
 > anyting else.  I would think that we could easily lump many
 > tiles together into these impostors to form a 2 level ring of
 > 'near' and 'far' "impostors" around our current scenery.  

Yes, I think that's a very good idea; in fact, if you wanted to go to
three layers, the furthest one could be simply untextured, coloured
polys (that's what you'd see from 120,000ft, for example).  For each
tile, we need to sample to find the commonest material and then use it
for the texture (and/or colour) at load-time.

Curt is worried about joining meshed tiles (with irregular terrain) to
flat tiles, but I don't think that will be a big problem if the flat
ones are far enough away.  If we wanted to, we could also sample the
elevation variation for each tile to help us decide how far away it
should be drawn as a full mesh: flat tiles could go to a single poly
much earlier than mountainous ones, for example.


All the best,


David

-- 
David Megginson
[EMAIL PROTECTED]


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