comp.lang.idl-pvwave archive: archive » Image plot on back wall

Home » Public Forums » archive » Image plot on back wall

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: Image plot on back wall [message #18021 is a reply to message #17968]

Sat, 20 November 1999 00:00

robert.mallozzi
Messages: 11
Registered: November 1999

Junior Member

In article <MPG.129f15c03f13cc8e98997e@news.frii.com>,
davidf@dfanning.com (David Fanning) writes on IDL object graphics:
> Martin Schultz (m218003@modell3.dkrz.de) shows that the
> Germans do too have a sense of humor when he writes:
>
>> OK. I guess, I see clearer now: it's not objects that I don't like, but
>> the applications that are built on objects! ... Nowadays
>> it seems we have to *talk*
>> to these machines and *ask* them to *please* try to accomplish at least
>> a tiny fraction of what we had in mind.
.
.
.
>
> The thing that absolutely makes object graphics so
> impossible on occasions is that you get absolutely
> no feedback on what has gone wrong. Since *everything*
> is possible, object graphics doesn't care if you
> rotate the surface under the rug where it can't be
> seen. Maybe that is where you intended to put it.
> Meanwhile you sit and stare at an empty screen for
> hours, whispering every incantation you know, hoping
> upon hope that *something* might show up to give you
> your bearings.

Well, I am not sure this will make anyone feel any better,
but if you have ever done any OpenGL programming in C,
this same situation occurs. You have to set up the view
volume, clipping planes, viewpoint, etc. correctly or
else you get the ubiquitous black rectangle, with "no
feedback on what has gone wrong." More that once I
sat there scratching my head wondering why the model is
not in the view. Sometimes it helps to start over and put
your model at the origin, then apply your transforms in
small steps, checking the scene at each step to be sure
your model is transforming as you thought.

For a good discussion of setting up 3-d views, take a
look at "Computer Graphics" by Foley et al. or
"3D Computer Graphics" by Alan Watt.

Regards,

-bob

--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~
Robert S. Mallozzi 256-544-0887
Mail Code SD 50
http://gammaray.msfc.nasa.gov/ Marshall Space Flight Center
http://cspar.uah.edu/~mallozzir/ Huntsville, AL 35812
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~

Report message to a moderator

[Message index]

		Image plot on back wall By: raouldukey on Thu, 18 November 1999 00:00
		Re: Image plot on back wall By: raouldukey on Tue, 23 November 1999 00:00
		Re: Image plot on back wall By: davidf on Tue, 23 November 1999 00:00
		Re: Image plot on back wall By: raouldukey on Tue, 23 November 1999 00:00
		Re: Image plot on back wall By: davidf on Tue, 23 November 1999 00:00
		Re: Image plot on back wall By: raouldukey on Tue, 23 November 1999 00:00
		Re: Image plot on back wall By: robert.mallozzi on Sat, 20 November 1999 00:00
		Re: Image plot on back wall By: davidf on Wed, 24 November 1999 00:00
		Re: Image plot on back wall By: raouldukey on Wed, 24 November 1999 00:00

Previous Topic:	control IDL process
Next Topic:	Number of colors of widget appliation

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Sat Oct 11 11:18:33 PDT 2025

Total time taken to generate the page: 0.80061 seconds