plib-devel

[Plib-devel] desperate plea for help

[Curtis L. O. <cu...@in...>]

Ok, I've been beating my brains on this for the last 48 hours and I'm
about ready to give up (except I can't, so I keep bashing my head on
it.)  I'm hoping that some kind soul will have pity on me and help me
out.

I'm sure I'm doing something stupid someplace, but for the life of me
I can find out what that is.

My ultimate goal is to build a nice generic sky with sun, moon, stars,
haze at the horizon, etc. all within the structure of ssg.  I'm doing
this for the FlightGear project, but I'm hoping that when I'm done
this could be a quick easy drop in for others who want to add a
decent/realistic sky quickly to their ssg-based projects. (with the
possibility of having all the astronomical objects placed correctly
for time and view position.)  Every one needs this because even indoor
worlds have windows, right? :-) I'm a good ways along with this
effort, but I've hit a problem with texturing.

I've tried to boil this problem down to an example that is as simple
as I can get it.  What I've done is try to build a simple object
(square), texture it with the "wood.rgb" texture for now, and add it
into the sky in the plib "tux" example program.

I'm attaching my changes to the "tux" example program (from the
plib_examples-1.1.8 distribution).  It's about 4k compressed (4 small
files) so hopefully I'm not blatantly violating list ettiquete.  This
includes a replacement Makefile.am, a replacement tux_example.cxx and
two new files: skysun.cxx and skysun.hxx.

Just untar this over top the examples/ssg/tux directory and you should
be able to build it.

You should see a wood textured square in the sky, but you don't.  This
is the problem.  Instead, you'll see a solid white square in the sky.
If anyone can tell me why the texture isn't getting applied and what I
can change to make this work, I will owe you a virtual beer ... no
make that a virtual 6 pack.  By tomorrow I may be handing out first
born sons.

I'm guessing this problem is centered around a screwed up opengl state
configuration, but I'm stuck ... I've tried everything I can think of.
The worst part is that I've gotten all kinds of texturing to work in
the FlightGear project ... I just can't get it to work in this simple
example.

Help!

Curt.
-- 
Curtis Olson   University of MN, ME Dept.       Flight Gear Project
Twin Cities    cu...@me...                  cu...@fl...
Minnesota      http://www.menet.umn.edu/~curt   http://www.flightgear.org

RE: [Plib-devel] desperate plea for help

[Norman V. <nh...@ca...>]

Curtis L. Olson writes:
>
>Ok, I've been beating my brains on this for the last 48 hours and I'm
>about ready to give up (except I can't, so I keep bashing my head on
>it.)  I'm hoping that some kind soul will have pity on me and help me
>out.

Ouch that has gotta hurt.
Since the grandmaster is out of ear shot
I'll do my best :).

>
>I'm sure I'm doing something stupid someplace, but for the life of me
>I can find out what that is.

Try moving the current_sun.initialize(); call 
to someplace after ssgInit();
like the end of 

BTW
You should look into using the new ssgContext class.

Hope this helps you get some sleep :)

Norman

RE: [Plib-devel] desperate plea for help

[Curtis L. O. <cu...@in...>]

Norman Vine writes:
> Curtis L. Olson writes:
> >
> >Ok, I've been beating my brains on this for the last 48 hours and I'm
> >about ready to give up (except I can't, so I keep bashing my head on
> >it.)  I'm hoping that some kind soul will have pity on me and help me
> >out.
>
> Ouch that has gotta hurt.
> Since the grandmaster is out of ear shot
> I'll do my best :).
>
> >
> >I'm sure I'm doing something stupid someplace, but for the life of me
> >I can find out what that is.
>
> Try moving the current_sun.initialize(); call
> to someplace after ssgInit();
> like the end of

Ahh, yes that helped tons ... thanks!

> BTW
> You should look into using the new ssgContext class.
>
> Hope this helps you get some sleep :)

Ok ... I'll take a look at that.

Regards,

Curt.
--
Curtis Olson   University of MN, ME Dept.       Flight Gear Project
Twin Cities    cu...@me...                  cu...@fl...
Minnesota      http://www.menet.umn.edu/~curt   http://www.flightgear.org

RE: [Plib-devel] desperate plea for help (SKYBOX)

[Dave M. <dp...@ef...>]

Curt wrote:

>My ultimate goal is to build a nice generic sky with sun, moon, stars,
>haze at the horizon, etc. all within the structure of ssg.  I'm doing
>this for the FlightGear project, but I'm hoping that when I'm done
>this could be a quick easy drop in for others who want to add a
>decent/realistic sky quickly to their ssg-based projects. (with the
>possibility of having all the astronomical objects placed correctly
>for time and view position.)  Every one needs this because even indoor
>worlds have windows, right? :-) I'm a good ways along with this
>effort, but I've hit a problem with texturing.

a worthy goal.  indeed, a clean solution would be of interest to everyone.
perhaps you should get it all working using straight glut/opengl first and
then integrate with ssg so you keep it simple until it works.

the best tutorial on creating skyboxes can be found at
http://www.gamasutra.com/features/visual_arts/19981023/skybox_01.htm

also, i saw that crystal space http://crystal.linuxgames.com just added
some skybox code they claim works

--mcdave

RE: [Plib-devel] desperate plea for help (SKYBOX)

[Curtis L. O. <cu...@in...>]

Dave McClurg writes:
> a worthy goal.  indeed, a clean solution would be of interest to
> everyone.  perhaps you should get it all working using straight
> glut/opengl first and then integrate with ssg so you keep it simple
> until it works.

Actually it is all pretty much working with hand crafted opengl.  My
problem is struggling with ssg and state handling ... or maybe mixing
ssg's state handling with random hard coded state changes sprinkled
throughout the code.  This is what I'm trying to clean up.

> the best tutorial on creating skyboxes can be found at
> http://www.gamasutra.com/features/visual_arts/19981023/skybox_01.htm
>
> also, i saw that crystal space http://crystal.linuxgames.com just added
> some skybox code they claim works

Right now I'm implimenting a sky dome (this is for a flight
simulator.)  But it would be interesting to add a skybox option
sometime as well.

Regards,

Curt.
--
Curtis Olson   University of MN, ME Dept.       Flight Gear Project
Twin Cities    cu...@me...                  cu...@fl...
Minnesota      http://www.menet.umn.edu/~curt   http://www.flightgear.org

Re: [Plib-devel] desperate plea for help (SKYBOX)

[Steve B. <sjb...@ai...>]

"Curtis L. Olson" wrote:

> Right now I'm implimenting a sky dome (this is for a flight
> simulator.)  But it would be interesting to add a skybox option
> sometime as well.

This sounds like a way cool thing that ought to be distributed
with PLIB somehow since a large fraction of SSG programs must
need this kind of thing.  For example, my Tux game 'draws' the
sky with a simple screen clear - it would be cool if it could
have clouds and stars and stuff too - but not cool enough to
make me want to go out and write the code to do it!

If there were a simple couple-of-lines setup command to build
a sky and then a one line per-frame update command, it would
be something I could imagine nearly everyone using.

It seems somehow wrong to bloat the SSG core library with this
kind of thing - perhaps an SSG utility library is needed to collect
such useful things.

I've been having thoughts of playing with other handy 'utility'
modules such as the movement/collision code in Tux_AQFH.

-- 
Steve Baker                  http://web2.airmail.net/sjbaker1
sjb...@ai... (home)  http://www.woodsoup.org/~sbaker
sj...@ht...      (work)