Surface from X/Y/Z Points.
Blitz3D Forums/Blitz3D Programming/Surface from X/Y/Z Points.
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| I need create a surface ( Terrain ) from a list of coordinates in XYZ format. The list is something like... PointNum, Description, X, Z, Y 4,TEST,22.950,-16.758,199.995 5,TEST,-75.044,19.454,199.461 6,TEST,51.060,-21.960,200.930 7,TEST,-88.051,44.489,199.229 ... Read the file and put the points in the 3D is easy, but... i dont have experience in surfaces... i try to make it... but, i can't. If anyone have a idea or example to make it, please help me. =) |
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| Is this your own terrain mesh? Or are you using Blitz's terrain commands? If so why don't you make a gradient map from your surface info instead? 0-256 colour grey scale. Save it out and then then just load it in using the load terrain command - means you don't have to mess about with surfaces. |
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| eee... yep, is an option, but... i need generate the heightmap first. And i not sure wich option is more complex... create a surface or generate a heighmap from the XYZ file. |
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| Suggest making another heightmap. A heightmap assumes uniform spacing in the x/z axis which is why you only need to store the y component. The data above is all over the place with strange coords ( 199.995 ?? ). It's definately not uniform in terms of x/z coords so it would probably be difficult to convert to an image. How much more data do you have? I could try something for you. I'm off work atm - just had a toe nail removed ( ouch ) so have time on my hands. Stevie |
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| Where are you getting all this terrain data from anyway? It sounds a bit long-winded when you could just airbrush some heightmaps in a paint program instead. |
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| @Stevie The file contain around 487 points... If you need see the file, Here is http://www.badmouse.cl/download/xyz.txt I update the first post, the format of the file is X,Z,Y... sorry for the mistake. Thx for your time. |
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| Ok, leave it with me. |
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See attached plot of X & Z coords.  They are too random so there is no chance of making a mesh out of them or a heightmap. The Y coord doesn't fluctuate much anyway, it's between 180-200. Do you really need to use this naff data? What are you trying to do? Suggest you start from scratch using a heightmap as Hujiklo mentioned. Stevie |
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| The data is from a topographic intrument. In the image, you can see the area of a real terrain. I try to make in a easy way the process of create a preview in 3D, without the complex process in the case of others software like "Autocad Survey". |
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| Hmm, you'd need to use some form of tesselation routine which I'm guessing is the reason some most would use "AutoCad Survey". It's extremely complicated to build a mesh from a bunch of random points but there is alot of stuff on google e.g. http://www.cs.berkeley.edu/~ug/slide/docs/slide/spec/spec_frame_meshnode.shtml |
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| I had this exact same issue the other day in writing code to produce a cartogram (in this case a mesh from points distorted by travel times). I didn't get very far - in the end went with manually selecting the points (with which to create the polys) and saving the resultant mesh plus point selection order to file. However I didn't have as many points to tesselate as you do... |
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| @Stevie Anyway, thx for your time Stevie. I have some ideas now, maybe i can do it... @MadJack Please, you can post some example from your code?. |
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| Tab Sorry - not for a couple of days - it's the weekend here in NZ and the code's on my work PC. But it wasn't that extensive - basically pick three points, create a polygon - the code's all available from the archives here on this site. |
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