Re: This could be useful
quite right, and before you know it we are back to the usual "toaster, lunchbox, Abraxo cleaner, motorcycle handbrake, tin can, medical brace, etc."
I have the most fantastic scenery model of a strip about 1km wide by 27 km long, a reasonably large playing area you might think.
12GB of raw data - just a dtm and trees, buildings roads etc
And my machine with 16 gig of ram, an i7 chip and quadro 3300 graphics card, can manage a few fps - unless i skin the surface and project high res images onto the data, in which case i get about 0.5fps.
The guys who make games for a living invest a massive amount of time and effort into squeezing things down, and doing smart things with textures to the point that the hardware can deal with it and still give a reasonable performance.
every vertex, every poly you add to that slows things down exponentially - more points makes more collision tests, and more points makes each test more complex.
and forget about algorithmic poly reduction - with the knob to the left it accomplished pretty much bugger all and with the knob to the right it ruins the models :-) for a first pass on a model, maybe, but after that takes judgement, not just combining polys with a surface normal within x degrees of one another.
have a play with 3ds max for a few years, then you get some appreciation on how incredibly detailed and complex the world around us is.