On Tuesday, 16 November 2004 21:32, Lee Elliott wrote:
> Just a thought... An alternative approach might be
> to make the textures dynamic so that the roads could
> be overdrawn on them before they're rendered.
>
> At first I was thinking it might be best to do this
> when each new segment of scenery is loaded, as it
> comes within the visibility limits, but that would
> effectively mean that FG would then have
> to hold unique textures for the entire visible
> scenery.
> This would have the same overhead as photo scenery
> for everywhere.
It would not be the same overhead as having unique
textures for the whole planet though!
FS2004 basically uses the principle you are
describing.
Only the "pattern textures" and GIS data (DEM,
landclass, roads, rivers, etc) are stored on disk and
the final textures are generated dynamically as you
fly along. Textures furthur away are rendered at a
lower resolution.
The pros are :
1. Very nice scenery because adjacent textures can be
blended together using mathematical algorithms (that
incorporate randomness) which makes for more natural
looking scenery
2. If you want to upgrade the scenery you just stick
higher resolution GIS data into the correct
folder/file. No rebuilding and redistribution of
scenery files are required.
3. You no longer need to use lots of primitives to
display the data because it's all incorporated into a
few textures. All you need is the DEM and the
generated textures and you're done.
The cons are :
1. New scenery engine
2. No high speed flights because most CPUs will not be
able to generate the textures fast enough. This is a
problem in FS2004 - just try doing Mach 5 on a
moderate system and you'll see the scenery turn into
grayish tiles with no textures applied until you slow
down.
Of course one could always make the dynamic texture
generator a little more clever so that at high speed
flying it generates lower resolution textures or
removes some geographic features like minor roads etc.
Paul
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