You might want to check out OptimizeIt (www.optimizeit.com)... It's cleared
up many-a problem for me.
> -----Original Message-----
> From: Discussion list for Java 3D API
> [mailto:[EMAIL PROTECTED]]On Behalf Of Bobby Martin
> Sent: Thursday, August 17, 2000 4:30 PM
> To: [EMAIL PROTECTED]
> Subject: Re: [JAVA3D] Terrible frame rates
>
>
> You get TONS of points. I really appreciate you looking into this; I
> haven't really been optimizing my code because I was assuming it was a
> hardware acceleration problem. You are 100% correct that the triangle
> search is linear (it used to be a tree search, but the other
> reasons that I
> needed the tree went away, so I quit building it. Doh!)
>
> I'll look into both changing the tree search to something more
> efficient (I
> was going to have the triangles track their neighbors and follow
> along that
> way; looks as if that just got moved up the priority list). I'll
> also look
> into some techniques to make the TransformChangeListener pay more
> attention
> to just how the transform changed.
>
> This helps a tremendous amount. If the fixed code would help you on
> anything you're working with, let me know and you'll get it as soon as I
> have it.
>
> Thanks a lot!!!
> Bobby
>
> You said:
> Well, I _know_ I have 3d hardware acceleration working. Next, yes, I do
> see a terrible frame rate... but frame rate depends on several things.
> First, of course, is having 3d acceleration, but second is what you as a
> programmer do _between_ frames. If you do tons of operations between
> frames, it's going to slow things down.
>
> For example, I noticed that even if I was just rotating to look around
> (which doesn't change my location), you were calling
> "DoomWalker.transformChanged" in "doRotateY". It looks to me like this
> function will keep the viewpoint above the ground as you move about.
> Since I am not moving about, just rotating my viewpoint, I commented out
> the "transformChanged()" call in "DoomWalker.doRotateY()" and WALLA,
> rotation is now up-to-speed.
>
> Bottom line: the problem is not 3d acceleration, it's your algorithm.
> You don't need to check for "terrain skimming" if you are just rotating.
> Second, your terrain skimming algo needs to be optimized. Looks to me
> like it's just a linear search. You probably need to do some regioning
> of some sort.
>
> Didn't look into your clipping problem...
>
> How many points do I get? Hope this helps. ;)
>
> -Lee
> J. Lee Dixon
> Software Engineer
> SAIC - Celebration, FL
> [EMAIL PROTECTED]
>
>
> -----Original Message-----
> From: Bobby Martin [mailto:[EMAIL PROTECTED]]
> Sent: Thursday, August 17, 2000 11:55 AM
> To: [EMAIL PROTECTED]
> Subject: [JAVA3D] Terrible frame rates
>
>
> I put up some questions here a couple of weeks ago about terrible frame
> rates I'm getting. Many people seem to have hardware acceleration up
> and
> going with no problems. Since this demo has failed to run at acceptable
> speeds on so many different PCs, I'd like to get someone who's sure that
> they have hardware acceleration to run the demo and tell me if they get
> the
> terrible frame rates (~2 frames a second, at best!) that I'm getting.
>
> Also, it does a few of the things that people have been requesting; i.e.
> the
> viewpoint maintains a set height over rough terrain as you move, and I
> calculate correct texture coordinates for tiling an image over the
> terrain
> surface.
>
> Also, it appears that my viewing distance is about 50 meters, even
> though I
> have added a ClipLeaf centered at the origin, with a bounds of 1000
> meters,
> and a back clip of 1000 meters. Bonus brownie points to anyone who can
> tell
> me why my clipping is wrong :)
>
> I have included all source, and you are welcome to use it however you
> like.
> If you fix bugs, please let me know.
>
> To run the demo, unjar it somewhere innocuous. From that somewhere, run
> "java com.navtools.cosmdemo.single.BrowseTerrain". (You have to unjar
> it to
> put the images somewhere it can find them.)
>
> You can use the number pad controls as in Doom (make sure the numlock is
> on). You can also use page down/page up to rotate the view by 90
> degrees
> down/up around the x axis. You can hop up/down 10 meters by pressing
> the
> u/d key. If you try to move while in the air, you will be popped back
> down
> to the terrain surface.
>
> One more thing: it takes a little while (less than a minute, though) to
> come
> up since it randomly generates terrain every time. It's supposed to
> load
> the previous terrain when you run it after the first time, but that bugs
> out
> (I think due to an error in JDK1.3 serialization). You _must delete
> HeightField.dat_ before each run of the demo after the first.
>
> Oh yeah, and my apologies for the crappy sky background. I have a
> better
> one, but it's 16 times as big and I figured I'd save some bytes.
>
> Anyway, as I said above: if anyone can confirm that this runs
> quickly/slowly
> on a hardware accelerated machine (bonus points for telling me why), or
> can
> tell me what I'm doing wrong with my clipping, I would be very grateful.
>
> Thanks in advance,
> Bobby
>
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