error

[xuxuxu0701]

when i running Raytracing Fundamentals .There is an error:AttributeError: 'numpy.ndarray' object has no attribute 'lower'

[brandondube]

Thanks for the bug report. At the moment, V0.21 release is blocked by the new raytracer, which under the experimental submodule has no guarantees of any kind. I originally implemented Spencer & Murty's iconic paper, but Welford had a series of papers which describe the analysis part of things, in a way that ends up threaded into the main ray-trace procedure. I have not finished digesting and implementing Welford's paper. For now the code is somewhere in between and broken.

[xujun0813]

when i running Raytracing Fundamentals，“plot_optics(pres, phist, fig=fig, ax=ax)” will show “AttributeError: 'Surface' object has no attribute 'F' ”. It represent Sag of z which sphere didn't have.