| Topic: terrain on a sphere
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 | terrain on a sphere | |  |
| Poster | : steveh | | Posts | : 83 | | Country | : Australia | | City | : Orange |
| | | | Posted by steveh on 22/08/2006 at 12:01:25
| | Hi All,
I have created a routine that generates height data for a terrain and want to modify the points of a mesh sphere to reflect that terrain, ie make it look like a planet. The data is held as a series of steps between latitude and longitude values. Can you give me any hints on how to do this ?
steve | |
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| | | | | | Poster | : riemer | | Posts | : 1392 | | Country | : Belgium | | City | : Antwerp |
| | | | Posted by riemer on 23/08/2006 at 02:43:47
| | I think what you're describing exactly is called 'bump mapping'. It is quite mathemitically, though, but you shouldn't be too scared about that when you start a project like that :)
So, the basic theory behind bump mapping: you have an information map (your height map) and a mesh (your sphere). When you draw every pixel of your mesh, you look up into your info map how much this particular pixel should be changed in height.
Now you still have to find for each pixel the direction in which this height has to change. In your case, this would be indicated by the normal.
Let me know if you can grasp this up to this point, otherwise I will try to explain it a little further.
This is best performed using shaders. I will start to put out the third series, and you're in luck: it's all about shaders ;) Expect the first entry this evening or tomorrow; then I'll start putting out new chapters on a dayly basis. Of course we won't be covering your exact example, but in the end you'll have a nice idea of how to implement your globe. | |
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| | | | | | Poster | : steveh | | Posts | : 83 | | Country | : Australia | | City | : Orange |
| | | | Posted by steveh on 23/08/2006 at 03:29:48
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Hi Riemer,
Yes, that does indeed make sense using the normal to adjust the level of the grid. Thank you for that. I look forward to your next series.
regards
Steve
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