I can not believe how seriously this topic is being treated. In my opinion,
anyone who needs to use physical models, understand and use mathemtical
concepts such as rotation and translation should understand the need for
radians, degrees is eye candy for those people who actually need to see
something ......
> I sent this off to the java3d-comments email. I'd like
> to know if other people are as willing as I am to rewrite
> existing code if it means never having to convert between
> degrees and radians again.
>
No .. I wouldn't be eager or in fact willing in any sense of the word to
rewrite any code .. I don't know what sort of code base you are thinking about
but I'm betting it's not a real world commercial endevour with tens of
thousands of lines of code ..... anyone can rewrite some mocked up tutorial
level code .... try getting teams of architects, designers and testers
together and tell them that we need to revisit a data storage issue cos there
are people out there who don't know how to divide by a constant
> e
> BUG: Java3D rotations are expressed in the internal
> format of radians rather than degrees.
>
BUG as you have said it to me is simply expressing your opinion .. it's not a
bug .. it's functionally correct and in line with the maths that is needed.
>
> WORKAROUND: Programmers must use math routines to convert
> angles into the internal format before passing as arguments,
> and again on return values to generate meaningful output for
> the user interface or testing/debugging.
>
well I think this seems to be your main point here .. that users don't want to
see some readout in radians .. and fair enough too ... but of course there are
conversion methods available ... and for user viewing of data there is nearly
always some sort of massaging to put it in a more palatable form.
To me this is not a valid point as you have expressed it.
>
> FIX: All rototation-related classes such as transformations
> and quaternions should accept arguments, or return values,
> in degrees and keep the implementation format hidden.
>
if it aint broken don't fix it !!!
>
> Radians may have nice mathematical properties, but these are
> only of interest to ... mathematicians.
Well actually there are of intererst to a lot of people .. but in my case I
use them as a basis of angular measurement because they are mathemtically
efficient and there are no ambiguities ... and the real requirement for me is
to make the calculations execute as quickly as possible ... if you could show
me that using degrees makes the algorithms run faster then I would agree that
they should be used .. simply for this reason ... as speed ( for me ) is one
major requirement....and working in radians or degrees doesn't really make
that much difference to me .... afterall .. as I said .. there are easy
convrersions between the two.
> New programmers,
> experienced programmers, 3D artists, architects, geographers,
> etc all think in degrees.
think ???? .... well not when I write algorithms I don't ... maybe when I see
something on the screen .... but that is as a user .. not a developer ....
I repeat .. anyone .. and I mean anyone .. who works in the science fields,
uses maths as a tool of the trade, should have no problem with radians.....
I also "think" that if a cat is in a box then it will always be there (
quantum mechanics shows me that I need to rethink this simplistic model ) ...
just because people "think" something doesn't make it valid ... or else the
world would still be flat ....
> Exposing radians makes coding,
> testing, and debugging tedious.
I really don't see how converting it to another number will make this process
better .... and again .. I do wonder what you really mean by coding and
testing .. to me there are teams of engineers working to spec to develop
something .. and a team of testers working to test plans testing the system ..
not some pseudo-student type sitting up late at night wondering why an image
only rotates a little instead of a lot.
> It makes it harder for
> lecturers to translate most textbook examples into computer
> code. (Quick: can gimbal lock occur after a rotation of 1.6707
> about an axis?)
>
do I care ??? .....if a lecturer can't understand the relationship between
radians and degrees ( and it's a linear relationship .. what't the hassle ?? )
then I really feel sorry for the students .. not only will they be stumped by
a trivial fact .. but they will not appreciate why radians are used for
serious calcualtions ....
>
> It will be easier to convert code from OpenGL, and easier for
> OGL programmers to switch to Java3D.
>
trivial point .. again .. the conversions are easy .. not a stumbling block as
you seem to try to make it out to be ....
>
> A counter argument is that radians are already used in VRML.
> That was a mistake and should not be imitated. I have never
> read any VRML tutorial/introduction that did not apologise
> for the use of radians, with some comment along the lines of
> "You'll get used to it." We don't.
try
> No student in my 3D graphics
> course has ever expressed satisfaction that VRML uses radians
> instead of degrees, and all have been delighted to move on to
> coding in OpenGL where it no longer applies.
>
I'm sure as your students gain understanding they will see that this is not an
issue .... to me it's like measuring temp in farenheit or celsuis .... who
cares .. easy conversions ... what's the big deal.
>
> Is this code incompatible with existing code? Yes, and I for
> one would gladly change my existing code if it meant that
> *every* future program would be simplified.
>
hah !! ... well ... if I was given the task of changing the existing code base
.. I might be on the gravy train for longer .. but I would be bored .. and
would be looking for another job where there are serious efforts in the areas
of simulation and visualisation .....
>
> Hugh Fisher
> ACSYS/CSIRO VE Lab
and you are working for a science organisation ..... this is really surpising
.... is this opinion expressed by scientists in this organisation ... or just
the students?
As I said at the beginning .. I really don't know how this topic could be
treated so seriously by some .... so while we are at it ( being prepared to
rewrite code for no apparent reason expect for the fact that people that
aren't "used to it" and don't like it .....) what about the right hand rule
.... I much prefer a left hand rule .. .would probably improve my typing speed
:)
The main point would have to be that there are easy conversion between the two
.. and radians is more efficient to implement ...... no issue in my opinion.
Andrew Fellows
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