Re: [Visualpython-users] how to visualize 3D surface?

[Bruce S. <Bru...@nc...>]

Sorry, but I'm swamped with other work and can't help with Python 
coding. Maybe someone else will give you some help. The "frames not 
aligned" sounds like maybe the problem could be that you can't add x**2 
and y**2 because these two arrays don't have the same lengths.

Bruce Sherwood

pri...@gm... wrote:
> hi folks,
>
> I am new to VPython so this question may sound a little bit naive;
> I've got a question concerning the problem how to visiualize a 2D-manifold in Vypthon. In this special case, the parameters are Theta and Phi to just plot a part of the surface of a sphere, where the Radius is constant. An additional feature would be that the surface is something like transparent or it also could be a spherical grid. I hope my english is not too bad, so that some of you could understand what my problem currently is. I hope I'll receive any help soon.
>
> Thank you very much.
>
> greets from germany
>
> -Philipp
>
>   
>> You might study the example program faces_heightfield.py that comes with
>> VPython, as it creates a surface.
>>
>> The most general VPython object is "faces" which lets you display
>> arbitrary triangles and specify lighting at vertices. This low-level
>> object could be used to display a portion of a sphere. Or if you want to
>> display a portion of a sphere as a grid, use the "curve" object.
>>
>> There exists a beta version of VPython which lets you specify that an
>> object is transparent. See the "Recent developments" section of
>> vpython.org. Unfortunately the Windows version has some serious bugs
>> (see the documentation in the Recent developments section) and there is
>> no Macintosh version. The Linux version mostly works correctly.
>>
>> Bruce Sherwood
>>
>> pri...@gm... wrote:
>>     
>>> hi folks,
>>>
>>> I am new to VPython so this question may sound a little bit naive;
>>> I've got a question concerning the problem how to visiualize a
>>>       
>> 2D-manifold in Vypthon. In this special case, the parameters are Theta and Phi to
>> just plot a part of the surface of a sphere, where the Radius is constant. An
>> additional feature would be that the surface is something like transparent
>> or it also could be a spherical grid. I hope my english is not too bad, so
>> that some of you could understand what my problem currently is. I hope
>> I'll receive any help soon.
>>     
>>> Thank you very much.
>>>
>>> greets from germany
>>>
>>> -Philipp
>>>   
>>>       
>
> thx for the fast post. just like you recommanded, i have studied this example, and also tried to plot my surface. but this heightfiled_faces.py example comes a little bit complicated and it also doesn't do that what I expected. i need to add that I am new to python and I just wonder that it doesn't seem to be easy to plot a 3D-surface (just like in mathematica for example). nevertheless, I would truly like to understand this example programm, and also what I made wrong in useage; here are the differences to the example prog:
>
> ############################
> theta = arange(0,pi/2.0,2./20)
> phi= arange(0,2.0*pi,2./20)
> x = sin(theta)*cos(phi)
> y = sin(theta)*sin(phi)
>
> m = Mesh( x, sqrt(1.0 - (x**2.0 + y**2.0)), y)
> ############################
>
> when I try to run faces_heightfield.py with these modifications, "frames are not aligned" occurs. maybe somebody could help me with this problem, I would truly appreciate it....Thank you very much.
>
> -phil 
>
>
>