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Submitted by , posted on 08 September 2000
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Image Description, by
My name's Rob James and I'm working on a new demo which amongst other things
is attempting to do some Terrain rendering (oh not not another terrain!)
Hopefully this one's a bit different because it's ray-traced in realtime and
doesn't need a Hardware 3D card :)
The terrain is based on the HybridMultiTexture code described in the
excellent book, 'Textures and Modeling - a Procedural Approach' by perlin,
ebert and musgrave. The core of this terrain algorithm is a sequence of
weighted calls to the standard Perlin Noise function, which traditionally
can be too slow for real-time use. This tiny demo renders a practically
infinite terrain via a 128x256 texture which is rendered into a 640x380
window. Both the Perlin Noise function (Noise2) and the HybridMultiFractal
Terrain function have been implemented using Intel SIMD (for 4-at-a-time
power!) so it will ONLY RUN ON Pentium III class cpus (Celeron II is cool
too). Using Intel Compiler 4.5 and hefty use of VTune (both demo's from
Intel Site) I have managed to get the code upto 16fps on a PIII-650 and
19fps on a Celeron-750. If there are any SIMD gurus out there that can cast
an eye across my initial efforts I would be happy to post the code.
ta ta
RobJames@europe.com
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