General Atlas Issues
by Jacob Dankovchik · in Torque Game Engine Advanced · 12/09/2005 (6:20 pm) · 10 replies
Been a while since I've really said anything, but I've been hard at work with L3DT and TSE. I've recently basically mastered use of the 2 together and now can get the results I want just about everytime. Today I decided to stretch this with a well-detailed 40 kilometer terrain and thats when some issues started showing up.
One thing I've been seeing with these large terrains is texturing issues. To make these work right i generally have an error metric of around 6 or so. However sometimes I need to turn the tree depth up as well and it seems when I do this with the texture and get relativly low leaf sizes, the terrain texture has a habit of cutting out unless I'm rather close to it.
Another issue was some collisions far out into the terrain. I found these when I was off-road Ork'ing. ;) At times my orc would just kinda sink below the terrain surface. I was still standing on something, but the collision was below the actual visual surface.
The worst that I found was the model jitters. I got these before when I conscructed my Worldmap mission with exteremly huge flat planes tiled out to make a distance that was the diameter of the Moon. At the time I assumed it was only caused because of the massive position coordinates however I was getting it just now with relativly small coords on a perfectly feasable map. What happens is all the seperate objects of the model start to shake. For example on the crossbow, the arrow shaft, fletchings, bow strings, bow sticks, body, segments of the gear, etc all shake indepenantly, causing a bunch of parts of the model to vibrate all over the place. It wasn't too bad in my Mountain test today, but very noticeable. On the Worldmap test it got so bad that my entire player turned into a cloud of limbs and model fragments.
Do any of these sound familiar? I certainly hope they are being looked at, espicially the model jitters. The first 2 just may be a product of my high error metric and awkward tree sizes and can be fixed with map tweaks. But the model jitters really scare me. If you need I can try to make a video of it.
Thanks.
One thing I've been seeing with these large terrains is texturing issues. To make these work right i generally have an error metric of around 6 or so. However sometimes I need to turn the tree depth up as well and it seems when I do this with the texture and get relativly low leaf sizes, the terrain texture has a habit of cutting out unless I'm rather close to it.
Another issue was some collisions far out into the terrain. I found these when I was off-road Ork'ing. ;) At times my orc would just kinda sink below the terrain surface. I was still standing on something, but the collision was below the actual visual surface.
The worst that I found was the model jitters. I got these before when I conscructed my Worldmap mission with exteremly huge flat planes tiled out to make a distance that was the diameter of the Moon. At the time I assumed it was only caused because of the massive position coordinates however I was getting it just now with relativly small coords on a perfectly feasable map. What happens is all the seperate objects of the model start to shake. For example on the crossbow, the arrow shaft, fletchings, bow strings, bow sticks, body, segments of the gear, etc all shake indepenantly, causing a bunch of parts of the model to vibrate all over the place. It wasn't too bad in my Mountain test today, but very noticeable. On the Worldmap test it got so bad that my entire player turned into a cloud of limbs and model fragments.
Do any of these sound familiar? I certainly hope they are being looked at, espicially the model jitters. The first 2 just may be a product of my high error metric and awkward tree sizes and can be fixed with map tweaks. But the model jitters really scare me. If you need I can try to make a video of it.
Thanks.
About the author
#2
Anther thing is to check where the coords are at. I've experience jitter around +-70,000 before. It's a floating rounding error and no game engine can fix rounding errors (not without emulating a double precision world and converting at render time). Maybe 64bit DirectX and graphics cards are less than 5 years away? I wish.
12/14/2005 (7:57 pm)
I've seen a strange model jitter effect on our ported tank pack. The strange thing is that it jitters on some machines and not others. Odd huh? Seems to like the Intel chips better (almost as if one of the TSE programmers has some connection with intel...hrm).Anther thing is to check where the coords are at. I've experience jitter around +-70,000 before. It's a floating rounding error and no game engine can fix rounding errors (not without emulating a double precision world and converting at render time). Maybe 64bit DirectX and graphics cards are less than 5 years away? I wish.
#3
12/15/2005 (12:55 am)
Very far far plane can also make this sort of thing worse.
#4
12/15/2005 (2:26 am)
Not totaly on topic, but: Earlier today I found a hole in my Atlas terrain. The visual terrrain was there, but collision wise it was empty. I get a "Error, no plane possible!" error when I try to collide with it with the Orc. I'm using a 8k x 8k HTC-created terrain. 
#5
I placed Kork on a terrain, and shot a few meters right of his position. He started moving across the terrain TO the position, and when I stopped shooting he appeared back on his spawn spot.
Unmodified TSE with only scripts changes made to crossbow.cs and aiplayer.cs
12/18/2005 (5:02 pm)
If you increase the crossbow's rate of fire, to something close to automatic.. you can experience models travelling (yes, travelling) a few meters when you shoot.I placed Kork on a terrain, and shot a few meters right of his position. He started moving across the terrain TO the position, and when I stopped shooting he appeared back on his spawn spot.
Unmodified TSE with only scripts changes made to crossbow.cs and aiplayer.cs
#6
01/01/2006 (6:19 am)
I often get terrain jitters when in one of the editor screens and start walking. If I close the editor the jittering stops. Don't know if it's relevant, but might help narrow down the code causing problems.
#7
01/01/2006 (9:33 am)
Well, are you talking screen jitters or model jitters? I get screen jitters all the time but I've only experienced model jitters when traveling great distances.
#9
01/03/2006 (12:28 pm)
Ah. The jitter we are refering to is for the models. However I get the screen jitters too, but at any time, not just after opening the editor.
#10
01/05/2006 (2:30 pm)
I've been getting the same issue that Josh has had...holes in the terrain, usually covering a decent area. I had tried changing some of the parameters for compiling the terrains, but more often than fixing the problem, the holes would just move to a different area. Any idea what causes this? 
Torque 3D Owner J.C. Smith