View Full Version : Inverted Terrain acting wierd

04-12-2004, 07:25 PM
Got a strange issue here, I'm working on an ONS map that takes place inside a cave. I have 2 terrains in my map, 1 everyone walks/drives on, the other one that makes the ceiling for the level. Wierd thing is that Raptors can fly straight up through it like it's not there, but cannot fly back down through it, and if you drop the raptor down to the inverted terrain and jump out of the Raptor, you fall to your death, all the way down to the floor terrain. And the Raptor stays above the inverted one!!!

Has anyone else discovered this issue, and possibly found a solution to it other than a couple hundred blocking volumes?

04-12-2004, 08:03 PM
weird...I'd help but I've never tried that before...

Dario D.
04-12-2004, 08:04 PM
(I dont know anything about Terrain, but I think>) I would think that the cave ceiling terrain is facing the wrong direction. In other words, you may need to flip the terrain upside down so that the true "top-side" of it is facing down. I think the raptors fly through it because it's as if they are underground.

How do I explain it better? Here's a regular terrain:

___/ \_/ \____/ \________

You can walk on top of it.
But, what if you moved it to the ceiling? You can walk on TOP of terrain, but can you still bump into it from underneath? If a raptor flies into the underside of your terrain, perhaps it's going right through because you're only supposed to colide with the top-side, not the underside.

I may be completely wrong, but if not, try flipping your terrain upside-down and seeing if it works.

04-12-2004, 08:18 PM
I had to adjust a setting in the terrain's properties to make it inverted to work as the ceiling. It works in all aspects except with the raptor. Missiles blow up on contact, even tried making a negative gravity zone, and it threw me straight into the upper terrain, and splat... I died hitting it, just like I would from the fall to regular terrain. from above, the terrain is invisible, but from below, it looks just like it should, but the Raptor can fly through it on the way up....:cry:

04-12-2004, 11:55 PM
i built a test map to see whats up (pun intended), looks like maybe the karma props for the Terrain actor aren't inverted along w/everything else, so vehicles aren't blocked properly (i.e., from below). i used your neg-grav trick to stick a Scorp to the upper terrain -- it's wheels stopped it from going all the way through, but once up there it was stuck, and invulnerable (even with a 'deemer), and though it could be moved out of the neg-grav region with rocket blasts, etc., it still wouldn't fall.

blocking volumes or a custom-fit collision hull (invisible static mesh) may be your best recourse.

04-13-2004, 05:55 AM
can anyone think of something that won't involve about a weeks worth of work?

04-13-2004, 01:47 PM
I really need help with this, Raptors are kind of needed in my map, to reach a couple areas that cannot be reached otherwise, and this map is frelling huge to be using blocking volumes for the terrain (which is not anywhere near smooth)

04-13-2004, 02:08 PM
I'll probably try out an inverted terrain myself (once I get bots to follow those little flying apples). I'll report back what I find out. I am too far away from UED at the moment to look at it.

04-13-2004, 02:37 PM
I would like to help you, but I do not have much experiance with the UED. I am more into 3ds max, however I might be able to offer some help.

You could set the stallZ to just below the roof of your cave, thus preventing raptors from reaching it. Then you would still have problems with terrain that drops below the stallz.

However, you can easily make custom collision boxes with the UED. If you dont know how I believe it is in a tutorial on Planet Unreal. The jist of it is, you can use the red brush to make a collision box of any shape you can make the red brush into. If you do it this way, try to make the box as smooth as you can, without having a ton of corners and vertecies. (It will help for optimization).

Other than that, I believe I read somewhere about being able to export your terrain into 3ds or Maya. Then you can easily make it into a static mesh and then bring it back into your level.

I hope this helps.

04-13-2004, 02:59 PM
Some nice ideas, unfortunately when I said large level, I mean HUGE (around 24000x24000 units in x,y) and the I need the blocking to be terrain forming. I don't have the first clue on using 3DMax, and I don't have the money to buy it. There's got to be some setting that I'm missing here, either in the terrain itself, or in the vehicles.... :cry:

04-13-2004, 03:09 PM
Originally posted by CMan
I believe I read somewhere about being able to export your terrain into 3ds or Maya. Then you can easily make it into a static mesh and then bring it back into your level.

not sure about exporting the terrain, but if you export the terrain heightmap, some 3D apps can use it (or an rgb or 8-bit GS version of it) as a displacement map for generating a low-poly static mesh version of the terrain, that can then be used as a collision hull.

i'll look into generating this kind of thing in Maya PLE & post back. sounds like a useful workaround.

btw, there' s no reason to think you're missing a setting -- not all possible mapping configurations can be anticipated & coded for -- otherwise, we'd never need patches! :D

("we don' need no steenkin' patches!")

04-13-2004, 03:32 PM
Here's a screenshot taken from inside a raptor flying above the upper terrain, you can see from the pic why it would be so hard for me to construct a bunch of collision blocks...


04-13-2004, 03:32 PM
You could set the stallZ to just below the roof of your cave, thus preventing raptors from reaching it. Then you would still have problems with terrain that drops below the stallz

just an FYI, if your using terrain, you can bounce the raptor past the stallz line. in ONS severence and Torlan the answer to this was to install kill zones.


04-13-2004, 10:29 PM
i was able to make an invisible collision hull in Maya 5 PLE that closely conforms to the upper terrain in a test map. here's some screenies:
this shows the upper terrain in the test map (for ONS)

the "heightmesh" collision hull has been added. this is how it was placed for in-game testing

the hull & the terrain conform closely.

in-game, this is as far as i could go before colliding with the heightmesh, whose bHidden = true so it's invisible in game but still blocks.

way up close to the upper terrain, the viewpoint camera gets cramped, so some separation between heightmesh & terrain is needed or the camera will take a view from above the terrain -- not good.

the test heightmesh was 100 units square in Maya 5 PLE, with a final polycount of 19600 tris (less than a 128 x 128 terrain). it was scaled in DrawScale3D to closely match the terrain size. fewer polys would mean less conformance to the terrain but should still work OK.

for Raptor collision to work, i set the static mesh properties UseSimpleKarmaCollision = false and UseSimpleBoxCollision = false, which means per-poly collision and some processor overhead, but remember that no one should be walking on it, just aircraft bumping into it.

'Khan, if this looks like something that you'd find useful, i'll post instructions on making the collision hull in Maya 5 PLE.

BTW, total R&D & testing time approx. 3.5 hours (made longer by the fact that my 2k4 UEd no longer opens the Actor Properties window -- i had to use the editactor command to set props. SLOOOOWWW...)

04-13-2004, 10:50 PM

very nice, and yea, I would love a walk-through on how to do this, I've been driving myself nuts just trying to export the terrain into Maya. (about 10 hours total, with no results... would've helped if I had a working knowledge of Maya to begin with though)

04-13-2004, 10:57 PM
well, it's gettin' late here on the EastCoast, so i'll write it up tomorrow & post it tomorrow eve. i have yet to figure out how to fix my UEd -- still no Actor Properties windows! i really don't want to re-install. i wonder if just replacing the UnrealEd.exe. would be enough...?

04-14-2004, 09:40 AM
I've got a cave map too in ONS. I also had the same problem, but decided to leave it a while as I wasn't sure as to whether I was going to make the roof of the cave a mesh or not. I thought about using a PhysicsVolume to force the Raptor down. But I dunno if that will affect the Raptor or not. Have yet to try. But it would be better performance wise than creating a custom collision for it in a 3D modelling program.

04-14-2004, 10:12 AM
mini-tutorial is written & tested, just needs to be put up as html, or maybe on the Wiki. i'll post a link this evening.

04-14-2004, 10:55 AM
I have plenty of webspace, I can host it for ya, just shoot me a PM.

04-14-2004, 11:15 AM
have you tried giving the collision negative values?

04-14-2004, 11:36 AM
Originally posted by {RA}SKYFURNACE
have you tried giving the collision negative values?

as in bBlockKarma = – true ????

don't think that'll work ;)

04-14-2004, 12:16 PM
Don't see why blocking volumes wouldn't be the best bet. Doesn't have to contour to every bump and crevice, just put a few in to make sure your terrain is covered... unless you want the raptor to get stuck on the stalactites.. then I guess I'd go with making an invisible mesh, but that'd suck time-wise I'd think. Dunno, goodluck.

04-14-2004, 12:22 PM
Originally posted by thesonofdarwin
then I guess I'd go with making an invisible mesh, but that'd suck time-wise I'd think. Dunno, goodluck.

couple or three hours at most, methinks, depending on how fast your box is. took me longer to write the tute. probably take a lot longer to make & place blocking vol's for a very large terrain area. but imo b-vols would be best, as they tax the CPU less. just a lot more work.

04-14-2004, 01:26 PM
Originally posted by thesonofdarwin
Don't see why blocking volumes wouldn't be the best bet. Doesn't have to contour to every bump and crevice, just put a few in to make sure your terrain is covered... unless you want the raptor to get stuck on the stalactites.. .

I want the Raptors to be able to duck/hide behind the stalactites, which means I'll need the blocking to contour to the terrain, which would take me about 2 weeks to get done (at the very least)

04-14-2004, 02:59 PM
This problem really intreages me. I am also planning to make a cave ONS map. (Hey, is there a trend here....) I would give details but I am still on the planning and concpet stage. I am still debating on wether or not to make the terrain in 3ds max.

I was talking to a fellow mapper and he gave me some insight into the problem. Making the terrain in UED or 3ds has advantages either way.

-Terrain is Optimizable
-Easier to create
-Have to have 2 terrains for a cave

Static Mesh (3ds):
-Only 1 terrain needed
-Greater flexability (not sure on this, i dont know the limitations of UED)
-Gets loaded into Vid Card Ram

Other than that I am still getting organized over here, but if you want to send me the map I could take a look at it and see if I can export the terrain to 3ds and turn it into a static mesh. This should make it so that the collision works properly.

EDIT: PM me and I will send you my email addy.

EDIT2: This may be a dumb question, but did you try setting UseSimpleKarmaCollision = false on the inverted terrain and see if it works. If this just makes no sense, plz ignore it ;)

04-14-2004, 03:23 PM
makes sense, but didn't work :(

I don't have 3DS, just MayaPLE5 (DVD-SE)

04-14-2004, 03:24 PM
imo terrains are much more flexible than using static meshes for large-scale landscape features. they're easier to texture "on-site", can be edited on-the-spot to accomodate changes in map layout, can be much more easily optimized, and can be lit more successfully if one is careful of the limitations.

that being said, there are some landforms that can't be done with terrain, so static meshes do have their uses in that regard.

afaik, UseSimpleKarmaCollision is only a StaticMeshActor property -- i've not seen it in the TerrainInfo props. anyway, the inverted terrain collides with karma objects OK, but from the wrong direction. i think that's part of the actor's hard-coding. if anyone can find a way to set the karma collision properly in the terrain itself, that's a much better solution. i just couldn't find anything to do that.

04-14-2004, 03:26 PM
I also have this problem, but I am putting it aside until long as possible. Besides raptors, any of the other vehicles can get stuck inside inverted terrain.

chipV2 can't wait to see your tutorial.

04-14-2004, 03:36 PM
for anyone interested, here's a map i just threw together with a copy of the inverted terrain in it. (don't want to share entire map yet ;))


04-14-2004, 07:46 PM
for this thread's subscribers: mini-tute's up...

heightmeshing (http://www.metrocast.net/~chipartist/heightmeshing/)

04-15-2004, 10:13 AM
Awesome tutorial!!! now I just gotta learn some more about Maya so I can make some use of the great info in the tutorial. :bulb:

04-15-2004, 11:53 AM
Very nice job on the tutorial. You might want to add however, for smaller terrains, (or terrains that are more 'rolling' than 'jagged') you could probly get away with quite a bit less polys. But, most people should be able to figure that out by them selves.

04-15-2004, 01:09 PM
jeez :bulb: I'm doing a cave level myself, personally I'm using hourences method,
box modeling/ polygonal modeling and then using mesh smooth techniques.
This method works very well If you know how to use max, my only problem currently is uvw mapping. I think I need to learn how to use uvwunwrap...

for those interested check the tutorial out.


04-15-2004, 02:45 PM
i like inverted terrains for large caverns & mesh modeling for the smaller scale stuff or that which terrains can't do.

here's some screenies of an XMP map i'm finishing up (no flying vehicles, so the collision hull isn't required):

XMP-Styx (http://www.metrocast.net/~chipartist/pizza50/Styx01.html)

04-15-2004, 10:10 PM
If you already haven't finished doing the heightmesh you may want to try this.

Instead of setting the terrain Inverted = true, you may want to play around with the TerrainScale property. By default the TerrainScale is set to 64 x 64 x 64. If you change it to 64 x -64 x 64 the terrain will act similar to inverted terrain. This will eliminate the problem you are having with the raptors flying through the terrain, and you do not have to use blocking volumes to stop them.

However, there are a few drawbacks. When you make the terrainScale values negative, it will messes with another axis with your existing terrain. BUT, if you make your cave ceiling from scratch with this method it will come out fine, and it shouldnt take to long, especially since it is a ceiling.
One other drawback is similar to just using an inverted terrain. A player can see through the "upside-down" down terrain, and sometimes even walk through it. So if the inverted terrain comes close to the ground, you will need to use blocking volumes if a player could reach it.

04-20-2004, 01:38 PM
still no go on this, and I am having a hell of a time trying to do anything with Maya :(

04-20-2004, 01:46 PM
id say pic a new theme :)

04-20-2004, 02:23 PM
Originally posted by TheGhengisKhan
still no go on this, and I am having a hell of a time trying to do anything with Maya :(

what about using Maya is giving you difficulties?

04-20-2004, 03:15 PM
learning to use it. lol

04-20-2004, 03:33 PM
Originally posted by TheGhengisKhan
learning to use it. lol
ah, one of those fundamental issues ;)

learning does take a while if you haven't done any modeling before, but imo if you can work with UEd, Maya is well within your grasp.

04-20-2004, 05:35 PM
bah humbug, maya sucks for game content creation :p use 3ds max 5 ;)

04-20-2004, 06:36 PM
Originally posted by CTFX1
bah humbug, maya sucks for game content creation :p use 3ds max 5 ;)

only if you don't know how to use it properly, but that's true of any app, Max included. i've done static meshes & character anims, find Maya just fine for both, 'specially since the new 2K4 plugin has a lot of things fixed compared to the previous. and PLE is free, also a significant factor if you don't want to pop for the retail version or use crackware.

i've used gmax, the Max equivalent of PLE, and find many of it's features lacking compared to Maya, though i'd probably use it more if they came out with the oft-promised gamepack.

it usually just boils down to a preference based on experience.

04-20-2004, 07:19 PM
mind you one thing I find really fustrating about max is that it doesnt use math, at least not the same sort of math maya uses. Which really sucks because max cant do much as far as booleans.
I spent roughly a year self teaching myself on how to use maya and I have to say I wasnt very pleased about my progress. Imo maya is better for animation/movies and max is better for games. I'm using max 5 and I really prefer it espeacially because of the dynamics and flexibility of the modifier stack. I hear maya has sort of a round about secret way of doing this but eh. I've used both programs for about a year and I'm very pleased with max. well anyways sorry for the ot, thread is about inverted terrain not which 3d app is better lol.

I wanted to point out though that you can actually import your terrain (yes unreal ed terrain the terrain itself not the heightmap) into max using the obj import plugin, import the terrain convert it to poly (simple as right click and go to "convert to poly" ;) )

the uvw's will be screwed so you would need to do the uvw mapping of the terrain yourself in max but If you spend just a few hours going through uvw unwrap tutorials you'll be running in no time. But of course you should know the fundamentals of max before trying this out. I'm going to be using this method in my upcoming map.