Curtis L. Olson writes: > > Andy Ross writes: > > That was my thinking when I started, too. But your math is a little > > off. Getting to a worst case resolution of 1 texel per screen-space > > pixel with unique texturing requires *vast* amounts of memory.
Yup, I doubt if we get to the 1 texel -> screen pixel level very soon :-) > My understanding of systems that impliment these basic ideas is that > step 1) is to give up the idea of seamless, non-blurry textures in the > distance. Every system I have seen blurs the textures excessively as > you go further in the distance ... that also yields a corresponding > texture blurry->sharp "popping" effect as you get closer to a new > area. And because the system typically has to do this stuff in a low > priority thread to keep up rendering rates, you can see by the popping > that the detail texture loading often lags and doesn't pop into full > detail until you are right over it. Some schemes use a continuously 'improving' progressive refinement i.e *all* texture and corresponing mesh is initialy loaded at lowest LOD and it is progressively refined prioritized by 'current' distance. The amount of blurry->sharp 'popping' you get is pretty much dependent on your paging speed. i.e. if you can load sharp enough LOD quickly enough popping is minimal. Since LOD requirements vary according to distance this is not much of a problem at high enough altitudes i.e. where the earth appears 'smooth' but is an area of 'active research' once the 'dimpling' of the surface becomes significant > It's easy for us to sit here and say it can't work (at least not very > well), but the hard headed ones will forge ahead anyway, attack the > problems and issues head on, and a few of those people will find > successful solutions and a place in the geek hall of fame. :-) :-) FWIW I am currently looking into a scheme based on ideas incorporated in this project http://globe.sintef.no/. The Aasgaard projection is quite interesting esp as it relates to data storage schemes, but I have *lots* of experimentation and learning todo yet Norman _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
