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07-13-2003, 10:42 PM
I have got some points with Z value(random), and how to draw terrain with these points? thanks

Mad_Musician
07-13-2003, 11:59 PM
HI!!
I think you can start to use Bezier patches, then u have to learn how to apply textures on it. For that u need a vertex arrayand then i would read some of super bible there are are nice examples there...
i hope this help bye

07-15-2003, 11:43 PM
Originally posted by Mad_Musician:
HI!!
I think you can start to use Bezier patches, then u have to learn how to apply textures on it. For that u need a vertex arrayand then i would read some of super bible there are are nice examples there...
i hope this help bye

Thanks
but the points I get is random,not as array in x or y direction, then how should do?

kehziah
07-16-2003, 12:05 AM
You're saying that your points are not regularly placed on a grid, right?
You should look for Delaunay triangulation.
You might start here : http://goanna.cs.rmit.edu.au/~gl/research/comp_geom/delaunay/delaunay.html

abhijeet_maharana
07-17-2003, 02:29 AM
u could also try out the ROAM algorithm.
i don't have the exact link but tutorial 8 at www.naturewizard.com (http://www.naturewizard.com) links to it. Its not exactly what u want but u could give it a try

Regards.


[This message has been edited by abhijeet_maharana (edited 07-17-2003).]

Obli
07-17-2003, 07:36 AM
"but the points I get is random,not as array in x or y direction, then how should do?"

You said you have the Z for each point. There should be no problem putting it in the right vertex coord.

If you are unable to figure out what Z belongs to what point then you're in bad trouble - this means you don't know your data!
Are you trying to generate the terrai procedurally? What is the problem? Can you provide more info? If you don't have them in an array, from where the Z samples come?

If they are just random, in the meaning you generate them calling rand() or stuff like that then you simply have to decide how much detailed your terrain will be and then sample it correctly - but I guess this is not the case.

apocalexiz
07-17-2003, 08:36 AM
i see no reason for not using heightmaps...or generating some bye perlin noise etc. but it depends on your needs, for a flight simulator...of course, heightmaps were not very useful http://www.opengl.org/discussion_boards/ubb/wink.gif

bye

Obli
07-18-2003, 01:25 AM
Originally posted by apocalexiz:
... for a flight simulator...of course, heightmaps were not very useful...

I'm interested in this. Why not?

apocalexiz
07-18-2003, 02:33 AM
because hightmaps got a limited size http://www.opengl.org/discussion_boards/ubb/smile.gif with the other algorithms, triangulation, fractal terrain generation you r able to create endless terrains at runtime...IMHO

bye

Obli
07-18-2003, 07:37 AM
Ok, but they are not as controllable... oh well, it does not matter.

I still have to see a noise-based terrain renderer at decent speed however. Got a link?

dorbie
07-25-2003, 05:40 PM
Rubbish.

There's a difference between random seeded data and real world data. Noise based terrain cannot give you real data that matches image based texture.

Height maps are common in "good" flight simulators that represent real world terrain, they are often reduced to some polygonal representations including level of detail information. Look for information on the ROAM algorithm etc.

This site may help: http://www.vterrain.org/

For an example of what can be done on a PC with polygons derived from heightmap information at difefrent resolutions try
http://www.earthviewer.com/

[This message has been edited by dorbie (edited 07-25-2003).]