Quote from: EgonOlsen on February 09, 2010, 08:03:52 AM
The first problem can have several reasons:
a) you are modifying the mesh in another thread without proper synchronization with the rendering
b) it can be a driver issue
c) it can be a hardware failure, i.e. a weak memory cell on the graphics card. I had the same problem with my old ATI 9700.
Do you have a screen shot?
The second problem might by an accuracy issue of the zbuffer. Screen shot?

 For the second problem, here are two screenshots:
These are both overhead views from some distance above the terrain, since the problem increases with viewer elevation.
Notice the streaked patterns, which fluctuate as you move the view.

Here's the second one:


It's more difficult to get a screenshot of the 1st problem (triangles which are occasionally stretched to random points) since it seems to occur completely at random and hence is difficult to reproduce.

I had adapted Egon Olsen's terrain demo so that it uses my own procedurally-generated terrain and water, but I ran into two odd problems:
1) occasionally there are random polygons which are stretched out of position, so that one vertex is in the wrong place and the whole poly is therefore elongated to a random point on the map. At first I thought it was a problem with my terrain generation algorithm, but the problems are random.
2) Low-lying terrain at or near a Y coordinate of 0 allows you to see part of the water plane underneath, even if I lower the water plane to -3 or -5 etc; there is still a patchwork pattern of water showing through in many spots, and the problem increases as the viewer position elevates.  The original terrain demo didn't have this problem.

Quote from: EgonOlsen on February 07, 2010, 09:15:39 PM
The webstart examples are rather old. The version of LWJGL that i was using back then didn't support 64bit. I should really update them...

What about the version of LWJGL included with the development files?  My main concern is the compatibility of my own JPCT-based app once I get it done, since I might do it as a webstart app rather than an applet. 

I recently got a new computer, and the webstart demos no longer run - apparently lwjgl.dll doesn't work with 64 bit systems.  The applet demos still work fine, however.
 Here's the error log for the Blue Thunder demo:
------------------
java.lang.reflect.InvocationTargetException
   at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
   at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
   at java.lang.reflect.Method.invoke(Unknown Source)
   at com.sun.javaws.Launcher.executeApplication(Unknown Source)
   at com.sun.javaws.Launcher.executeMainClass(Unknown Source)
   at com.sun.javaws.Launcher.doLaunchApp(Unknown Source)
   at com.sun.javaws.Launcher.run(Unknown Source)
   at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.UnsatisfiedLinkError: C:\Users\Allen Williamson\AppData\LocalLow\Sun\Java\Deployment\cache\6.0\13\12c04e0d-2de90f37-n\lwjgl.dll: Can't load IA 32-bit .dll on a AMD 64-bit platform
   at java.lang.ClassLoader$NativeLibrary.load(Native Method)
   at java.lang.ClassLoader.loadLibrary0(Unknown Source)
   at java.lang.ClassLoader.loadLibrary(Unknown Source)
   at java.lang.Runtime.loadLibrary0(Unknown Source)
   at java.lang.System.loadLibrary(Unknown Source)
   at org.lwjgl.Sys$1.run(Sys.java:75)
   at java.security.AccessController.doPrivileged(Native Method)
   at org.lwjgl.Sys.doLoadLibrary(Sys.java:68)
   at org.lwjgl.Sys.loadLibrary(Sys.java:84)
   at org.lwjgl.Sys.<clinit>(Sys.java:101)
   at org.lwjgl.opengl.Display.<clinit>(Display.java:108)
   at com.threed.jpct.GLHelper.findMode(Unknown Source)
   at com.threed.jpct.GLHelper.init(Unknown Source)
   at com.threed.jpct.GLRenderer.init(Unknown Source)
   at com.threed.jpct.FrameBuffer.enableRenderer(Unknown Source)
   at com.threed.jpct.FrameBuffer.enableRenderer(Unknown Source)
   at com.threed.jpct.FrameBuffer.enableRenderer(Unknown Source)
   at com.threed.jpct.demos.bluethunder.BlueThunderRel.initWorld(BlueThunderRel.java:75)
   at com.threed.jpct.demos.bluethunder.BlueThunderRel.main(BlueThunderRel.java:52)
   ... 9 more
------------------------

Do you have any plans to add a water reflection feature?  Don't graphics cards do this automatically?

I haven't been able to find any information on this, so I'm posting a question.
What's the best way of rendering water so that it reflects the landscape?   

[Edit: Ok, it turns out that my program modifed config.farplane in several places, and I was trying to extend the range by foolishly changing the first one rather than the last one..... Nonetheless.... I'll leave a few of my previous comments below just in case someone wants to look at the unusual viewing distance achieved in Wurm Online, a Java webstart game which uses a rendering engine somewhat similar to JPCT except JPCT seems considerably faster and doesn't bog down my HD the way Wurm does. Perhaps someone can use JPCT to make a faster version of Wurm, a game which not only allows you to see for miles into the distance, but also modify almost every aspect of the landscape.
If you want to see what I'm referring to, here are some links to screenshots from Wurm - not very good ones, but it's difficult to convey the effect in a still photo.
This one shows the variation in detail - individual grass textures in foreground, billboarded trees in midground and minimally-detailed mountains in the distance - and the mountain is distant enough so that it would take you a considerable amount of time to walk there in the game - http://wurmonline.com/forum/index.php?action=gallery;sa=view;id=390
Another good view, this time from a high elevation that allows a panoramic view of a city and the distant mountains miles behind it - and to get some idea of the distances visible in this view, take a look at the city in the midground: the large complex of buildings on the artificial mound is large enough to fit hundreds of players, and the statue to the left of it is a "colossus" perhaps twenty times taller than a player character - http://wurmonline.com/forum/index.php?action=gallery;sa=view;id=367
Another shot of distant mountains - http://wurmonline.com/forum/index.php?action=gallery;sa=view;id=572
A YouTube video showing a tour of a (now abandoned) fortress called Fort Mole. The video allows you to see the game in motion. As with nearly every location in Wurm, the entire fortress was built by players one brick at a time, one plank at a time - in fact the bricks, planks, and nails have to be made by players as well. You can also terraform the landscape and build entire islands, one shovelful of dirt at a time. -  http://www.youtube.com/watch?v=YKcF8TFWO3w&feature=related

(Edit - I think I solved the problem)

I couldn't find any information on this in the docs, so I'm asking here:  what is the maximum functional value for farPlane ?  I've tried setting it as high as possible but there comes a point when it no longer extends the view.

Quote from: EgonOlsen on January 04, 2010, 09:59:01 PM
However, here's the file: http://www.jpct.net/download/misc/terrain.zip

Wow. Even on my machine, it runs with a framerate in the 20s or 30s, sometimes 40s or higher.
Since you provided the sourcecode, I assume we can freely adapt it for our own projects?

BTW, how did you make the sky in that program?  Are there any articles on creating a good sky?

Quote from: EgonOlsen on January 04, 2010, 09:08:29 AM
No, that's not the problem. What card is that exactly (if you are on windows, try downloading GPU-Z to find out in case you don't know it)? That it's a new system doesn't really mean that the graphics card is any good...
About how many "chunks" are we actually talking here?

At that time there were 25 chunks, each with 800 triangles; but as I said it runs extremely fast when the chunks are arranged in proper locations - even when I move the camera to a location where you can see most of the polygons at the same time - in fact it runs fast even when I quadrupled the number of chunks. It's only when they're all placed at the same origin that it slows to a crawl. Could the problem have something to do with collision detection?  Each chunk is set to mode "COLLISION_CHECK_OTHERS".

Quote from: EgonOlsen on December 28, 2009, 11:33:12 PM
I hope to manage that within a week. I'm a bit short on time right now and i'm still optimizing jPCT for this usage. I've already increased performance of that test case by 50%, so it should be worth the wait.

  Is it done yet ?

Quote from: EgonOlsen on January 03, 2010, 02:46:33 PM
Well, then it's hard to tell without knowing exactly what your are doing and what your hardware is. There's no performance penalty when objects overlap, so this has to be something else. Maybe some lighting calculations or limited fillrate of the graphics card (but then, it has to be pretty crappy..is it?).

Are you using compiled objects (http://www.jpct.net/wiki/index.php/Compiled_objects)?

 Yes, I'm using compiled objects.  Would that cause the problem?  My graphics card is a new, modern one - my computer is only a few months old.

Quote from: EgonOlsen on January 02, 2010, 09:23:40 PM
Which renderer are you using? The hardware one, i suppose?

  Yes.