Plot data on NURBS Surface

[John Walmsley]

Dear Dr Bignol,

Firstly, thanks for creating and maintaining this handy package - it is greatly appreciated.

My question: we are trying to plot function values on a NURBS surface. In this case, the function is a function of the surface parameters u and v - it's the components of the metric tensor. Is this possible in NURBS-python? There is an example in https://nurbs-python.readthedocs.io/en/5.x/visualization.html#examples which comes close to what we want. This case seems to be plotting z(u,v) using a colour map, but the code doesn't explicitly calculate this. Can we do something similar instead using our own calculated function values as the colour value at each point on the surface?

Thanks in advance,

John Walmsley

[Onur Bingol]

Hello John,

This sounds more like a Matplotlib-related question if I understand it correctly. The surface example (https://nurbs-python.readthedocs.io/en/5.x//visualization-3.py) uses a colormap that comes with the Matplotlib package. It seems to be possible to create custom colormaps with Matplotlib, but I don't have any experience with that. I've found a tutorial on creating custom colormaps and a code example: 

• https://matplotlib.org/3.1.1/tutorials/colors/colormap-manipulation.html
  
• https://matplotlib.org/examples/pylab_examples/custom_cmap.html
  

An alternative method could be evaluating the surface and your function at the same (u, v) values (see "sample_size" property of the "Surface" class) and plot them together with any visualization software.

I hope these help a bit.

Thanks,

Onur

Onur R. Bingol, PhD

con...@onurbingol.net | https://onurbingol.net 

---- On Mon, 16 Nov 2020 18:35:05 -0800 John Walmsley <johnwa...@gmail.com> wrote ----

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