POV-Ray : Newsgroups : povray.binaries.images : Rotation matrices : Re: Rotation matrices Server Time
9 May 2021 06:33:16 EDT (-0400)
  Re: Rotation matrices  
From: Bald Eagle
Date: 4 Apr 2021 20:10:00
Message: <web.606a545e565eea121f9dae3025979125@news.povray.org>
"Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:

> Nice illustration.

Thank you, Sir.

> To improve it I suggest that you remove the decimals. This will give you some
> more space and make it easier to read.

Yes, I was waffling on that - too many, too few...   hard to judge.
It's always tough to try to squeeze a lot of information into a limited space.

There's a weird 3-fold aspect to the way the vectors are represented in the
matrices that I'm trying to capture, but unsure what the best way to go about it
is.   Each row is an x, y, z basis vector.   Each column of that row is an x, y,
z vector component.  And then the final transform is the "sumproduct" for all of
the columns - the x' vector is x.x + y.x + z.x + w.x
So I left all of that criss-crossing out for now. ;)

> I also suggest that you insert a note to the reader that POV-Ray's trigonometric
> functions use radians, not degrees as in you[r] basis vector lists.

I will keep that in mind.  I have one or two other "documentation illustrations"
in mind.  I would also like to figure out if there's a nice
degrees-to-fractions-of-pi algorithm out there, and I could implement that.
I'll probably just hard-code an array of text objects.

> Further; some of the equal signs have become minus signs. Could this be caused
> by some scaling of the image ?

IIRC, it's an antialiasing thing.  I noticed it, but let it slide, hoping for
more feedback before I revised the entire thing.   Maybe I'll see if I can find
a bold font to replace 'timrom' with.
Or maybe I'll just scale the font in the y-direction a little bit to thicken the
horizontal lines.

Do you watch 3blue1brown's channel?   It's - peaceful, and elegant, and
mesmerizing.  It's one of the best things to happen to math in a long while.

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