Re: Re: photo

David Luff wrote:
> On 1/5/04 at 10:19 AM Curtis L. Olson wrote:
> 
>>I would suggest that if you are using satellite photos for scenery,
>>you probably want to get rid of the GSHHS coastlines entirely.  Just
>>let the imagery do it's thing.  In this case you really just want an
>>image drapped over terrain, and you probably want to ignore *all* the
>>2d polygon stuff in terragear.
>>
> 
> 
> You you have any thoughts on whether it would be better to have tile-sized
> images in this case, or still make the images smaller than one tile (1x1 or
> 0.5 x 0.5 km, say) and feed those areas as the only polys?

If you are asking me, then I will say this is primarily a texture 
management issue.  The amount of texture is the same no matter how you chop 
it up.  If I'm doing the math right, this is true even if you factor in 
mipmapping.  1 - 1024x1024 texture is equivalent in memory usage to 4 - 
256x256 textures.  There might be a very tiny state changing cost for using 
additional textures, but probably not even close to noticable in this case.

So I would say it primarily boils down to your texture management scheme 
and the size of textures you want to deal with.  If you can cover an entire 
tile with a 1024x1024 texture then that might be the easiest.

If you want to support older video cards, you might want to chop all your 
textures down to 256x256.

At some point we need a real photo texture paging / management scheme if we 
want to do any serious photo scenery ...

Curt.
-- 
Curtis Olson   HumanFIRST Program               FlightGear Project
Twin Cities    curt 'at' me.umn.edu             curt 'at' flightgear.org
Minnesota      http://www.flightgear.org/~curt  http://www.flightgear.org