Re: OpenGL scenegraph

[Jan Ekholm <chakie@infa.abo.fi>]

On Sat, 4 Sep 1999, Steve Baker wrote:

>Jan Ekholm wrote:
>
>> So, I ended up
>> creating an own simple scenegraph on top of OpenGL. It is very
>> lightweight, easy to use and still somewhat limited in functionality,
>> maybe even buggy. It however worked fine for displaying the proteins I
>> needed it for...
>
>It sounds a lot like 'ssg' (SimpleSceneGraph) - which I maintain as a
>part of PLIB  http://www.woodsoup.org/projs/plib

Yep, I know! I ended up writing my package as a result of not finding
anything which would implement a good scene graph a year and a half ago. I
think I could have gone with 'ssg' then, as it's open and it works, but I
didn't know about it.

>> Now I wonder if someone is interested in using such a beast,
>
>About 300 people are signed up to the PLIB users list and 150 or so to
>the developers list - so there is certainly interest in such things.

Sounds interesting. :-) But my humble effort is still to a large extent
not thoroughly tested nor fully implemented. One good thing I think can be
worth mentioning is that it does not force anybody to use any kind of
toolkit, it works everywhere where there's a window which would accept
plain OpenGL, e.g. glut, the Qt QGL widget and probably the Gtk equivalent
(name?), as well as the Motif GLRenderArea.

>I refer you back to the long thread (that just wound down) about why
>there are so many near-identical packages out there - and why you can
>never get someone (like me) to give up my package to work on yours (or
>vice versa).

Multiple packages are IMHO a good thing. Evolution will most likely let
the best and strongest survive (although not in Kansas). Basically I don't
really care that much if my package lands belly up, as I do this for the
fun of it, and most of the development was paid anyway. Had I done it all
for 'free' I think I'd have a much stronger emotional attachment to my
code (as with my networking lib Zombie).

Btw Steve, thanks for the nice docs on OpenGL you have on your site. I've
been reading a couple of them while trying to figure out how to properly
combine several rotations into one single rotation in order to avoid some
weird effects. Still struggling, so I had to write a Matrix class to try
out the theories in practise... :-)

---------------------+------------------------------------------------------
 Jan 'Chakie' Ekholm |    CS at Åbo Akademi University, Turku, Finland
    Linux Inside     | I'm the blue screen of death, no-one hears you scream