POV-Ray : Newsgroups : povray.general : <no subject> : Re: <no subject> Server Time
23 Feb 2024 12:07:41 EST (-0500)
  Re: <no subject>  
From: Bald Eagle
Date: 21 Jan 2024 19:10:00
Message: <web.65adb15e6f92e8561f9dae3025979125@news.povray.org>
Hi Thomas,

Buckminsterfullerene (BF) is quite interesting - I remember clearly when they
were discovered in 1985 - it was a big deal, even though I was only in HS and
didn't understand why (yet).

From a didactic point, you should have started with basic bonding,
Hund/Aufbau/orbital-filling, VSEPR, and orbital hybridization to show how atoms
bond, why they adopt the shapes that they do, and explain why certain atoms have
the number of bonds that they do.  And of course, since we're talking about
Buckminsterfullerene, you should probably mention aromaticity, and what makes BF
interesting and why its discovery was so important, and why 3 people won the
Nobel prize for its discovery...
(Even if you only do so VERY briefly.  You could also just talk about it and
provide links in your video description / GitHub)
I know, I know....

Although I'm personally happy that you covered the topic, I think you might
scare off some people by diving right into the geometry of dihedral angles, etc.

"Reflecting all the time I invested in this molecule, it seems pretty easy to
model, ..."  Maybe.  I haven't tried your way yet, and when I looked at your
code on GitHub, it's 1134 lines.  I think it might be time to introduce arrays
and macros, and the blessings of shorter code.  :)
Also, if you're thinking of modeling larger molecules, maybe #read from ASCII
CSV file would be a good topic to cover in advance.
(I found an .xyz file at:
https://www.researchgate.net/profile/Marco-De-La-Pierre/publication/308325208_Coordinates_of_nn_fullerenes_with_n_1-10_
xyz_format/data/57e0cdc608ae3f2d793ebb43/fulle-xyz.zip
)

Since Buckminsterfullerene is a truncated icosahedron, I used the description of
the vertices here:
https://en.wikipedia.org/wiki/Truncated_icosahedron
and once I puzzled out the meaning of the "even permutations" part, I think I
have all the vertices plotted.  (without having them all connected it's hard to
tell)
(I was really hoping that someone had invented some sort of amazing parametric
equation that would give the vertex locations as the result!  :D )

Maybe once I have it all worked out and connected with bonds, I can compare the
positions of atoms in each model.

It's interesting that you do almost all of your work with blobs.
First, blobs were developed by James Blinn to model DNA for Carl Sagan's
_Cosmos_.  So, there's some wicked cool history there.
One of my very first renders in the early 2000's was a DNA double-helix!  :)

Second, jr was just asking about blobs, and I found a lot of interesting
information about how metaballs can be implemented, with different shapes other
than spheres, and using different smoothing functions.  Pixar's Renderman has
some pretty impressive stuff in that area.

I noticed that you had some interesting creases in the contours of your blobs -
I'm wondering if we can improve on POV-Ray's stock blob implementation...

Overall, a nice video, showing how to build up a complex structure, layer by
layer, and using symmetry to simplify the task.

Another interesting way to model the 2nd half of the structure would be to use
the symmetry through the center of inversion.  And maybe the lower half could be
simplified into 5 sections that could be copied by rotation.
http://www.creative-science.org.uk/c60group.html

I'm looking forward to seeing what your future ideas for the series are!

- Bill


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