Outerra forum
Outerra Engine => Ideas & Suggestions & Questions => Topic started by: ZeosPantera on June 10, 2011, 03:07:41 am
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Although the finer details of modeling and exactly how fractal generation works currently slips my mind. The thought has crossed it that the same system allowing 50 square miles of accurate terrain to occupy 100 megs why couldn't a point cloud for a model be seeded and filled with tiny fractals? It would allow unlimited LOD and models would no longer need to be an actual file. It could just be a complex seed string.
(http://4.bp.blogspot.com/_eMU4_PS7NFo/TI9l4rfo3qI/AAAAAAAABZ0/JPkVNPeowO0/s400/Vector_illustration_ferrari_wireframe.jpg)
So educate me in why this isn't possible since it makes sense in my mind. Cover a Ferrari 458 Italia with 10000 points and fill it in with fractals when you need the detail and 1000 points at a distance etc. Again, I KNOW NOTHING!
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In theory it could, but ...
Fractals are used to simulate natural phenomena, features that have been created by natural processes that act on wide range of scales. Why fractals work for simulation of these processes is because they apply a relatively simple rule recursively when generating finer detail, achieving the self-similarity characteristic for these phenomena.
With vegetation it works because the DNA sequences determine the growth of plant parts are often being applied recursively as well.
But with regards to man-made objects, the only area it would work well this way is when the objects are subjected to natural, recursively defined processes. For example, how the rust eats the metal :)
Adaptive tesselation can be viewed as a recursive subdivision of surfaces, so that you'd get smooth surfaces out of a rougher definition. It's probably too much of a generalization to call it a fractal process though, because there's practically nothing random about it.
Fractal processes can be still used here though, mainly with the use of procedural materials, and with procedural approach to applying dirt and rust.
Using it all with point clouds would be certainly possible, but it all needs someone who'd deeply focus on this area. Because as always, the ideas fly like angels, but the devil is down in the dirt with the details ;)
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Isn't it very hardware-expensive to constantly do fractal-calculations?
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Isn't it very hardware-expensive to constantly do fractal-calculations?
Yep, for any reasonably complex fractal function.
Without caching and effective management it would all crawl.
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I think that more effective way than fractals in this case should be proper usage of tessellation shaders in GL4.1. But there exists a technology that is capable to handle hi-polygon meshes in different way. It is something like Carmack's mega-texture but it works on the geometry.
here is presentation video and paper about the technology
[video]http://www.youtube.com/watch?v=pAyqryrN-I0[/video]
http://miciwan.com/GDC2011/GDC2011_Mega_Meshes.pdf
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here is presentation video and paper about the technology
Fantastic technology. And they managed to get all that on xbox360 in realtime
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It looks fantastic! O.o
Quite funny how they conveniently blurred the edges of the screen so you don't notice the popping as much. :p
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I'm stupid....what am I looking at thats so fantastic?
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I'm stupid....what am I looking at thats so fantastic?
100 billion polygons and 16 32k x 32k textures in the scene with GI lightning (http://www.youtube.com/watch?v=cdcqtjlBWCE&feature=related) in real time with 30fps on the 6 years old console system with 512mb RAM, that's really remarkable