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# MythOpus/Race Nation

Race Nation

I have quit the team (this has been for some time now). But I am going to keep this page here as a reference for me or anyone else who wants to read it

#### Race Nation... What is it?

Well... Race Nation is a mod focused on cool cars, fast racing... and totally customizable. Curently, I am the only coder on this project and sadly, I don't know all the facts... However the team leader will be finishing the Game Plan and info and stuff, so I will get oyu more info on this subject when it becomes available.

#### Who Am I?

Hm... well I am MythOpus I have been a mapper for a long time (since Unreal) but none of my maps have been good enough to release... however I am also a coder. Not a noob coder exactly.. but not an expert either... Somewhere in the middle of noob and experienced Anywayz... my job in this mod is to code the vehicles and all the other stuff needed to make this mod work. Of course, since I am not too good at making advanced stuff (GUI's etc.) We WILL need major help on this project !

### Updates

September 29th, 2003

We are hard at making models and so far, I'm still trying to fix the test vehicle (which, acording to Foxpaw needs have a Karma Collision) so while I try to sort that out... we have a site layout finally but sadly not an actual site. (this is an update at school so I have no tiem to do a real update.) Gotta go though, l8r !

October 1st, 2003

Well, with the help of Foxpaw (Thx) I have managed to fix the problem. However... now we have another proble Whenever the Factory summons the vehicle, it keeps 'jumping' on to it's rear end I have some theories on why it is doing tihs and will test them out soon, but It would be helpful to know of the problem now

Foxpaw: Can you explain what you mean by it's jumping on it's rear end? Aws in-it's acting like one of those lowriders with hydraulics on it, the back tires are bouncing off the car, the whole car is acting like Tigger? If it's the latter I've had that happen numerous times, I'll try to remember what causes it if that's the problem that you're having.

MythOpus: Well, hm... the front end, as soon as it is spawned shoots up so the vehicle is standing vertically on its back 2 tires...

Foxpaw: Well. That's something all right. A couple of things come to mind but you've probrably already thought of them. It sounds like the center of mass on the cars is not in the correct place. This could be a symptom of the mesh not being centered when you imported it into UnrealED (unlikely though if the tires line up) or the center of mass being overridden. I think I recall you mentioning at one point that it's subclassed from the bulldog, which has it's karma parameters set up like this:

        Begin Object Class=KarmaParamsRBFull Name=KParams0
            KInertiaTensor(0)=20
            KInertiaTensor(1)=0
            KInertiaTensor(2)=0
            KInertiaTensor(3)=30
            KInertiaTensor(4)=0
            KInertiaTensor(5)=48
        KCOMOffset=(X=0.8,Y=0.0,Z=-0.7)
            // ... and then some ...

Anyways, the KarmaParamsRBFull overrides the interia tensors and Center of Mass of the Karma object you're simulating. (Regular KarmaParams determines these automatically, but that's probrably not ideal if you want an accurate driving game because it assumes uniform density.) Anyways, if your cars are subclassed from the bulldog they will have the same center of mass shown above, which is slightly to the rear and down somewhat. (The bulldog is backwards, so that 0.8 is actually 0.8 to the rear.) The COM offset is also specified in Karma Units, which in this instance happen to be exactly 50 times an Unreal Unit. This is then further scaled by the drawscale.

If you think this might be what's wrong, try putting this in the default properties. It should override the bulldog's KParams so you can see if it's really the center of mass causing the trouble. Optionally, you could just type in KDraw COM on the console and see where the center of mass is, but it could be underground or something so it might be hard to see:

        Begin Object Class=KarmaParamsRBFull Name=KParamsExperiment
            KInertiaTensor(0)=20
            KInertiaTensor(1)=0
            KInertiaTensor(2)=0
            KInertiaTensor(3)=30
            KInertiaTensor(4)=0
            KInertiaTensor(5)=48
        KCOMOffset=(X=0,Y=0,Z=0)
        KStartEnabled=True
        KFriction=1.6
        KLinearDamping=1
        KAngularDamping=1
        bKNonSphericalInertia=False
            bHighDetailOnly=False
            bClientOnly=False
        bKDoubleTickRate=True
            Name="KParamsExperiment"
        End Object
        KParams=KarmaParams'KParamsExperiment'

MythOpus: Hm.. I'll test this out Thanks for the help and support BTW

October 11th,2003

Well, I've been away for quite awhile... grounded... but hey what can you do? Anyways... last night was the last night of my grounding but I went for a walk with my ... I guess you could say girlfriend, but we lost eachother (don't ask) but even after that I was busy getting my ownage groove back with UT2k3 which I haven't played in a half a year > to a year but anywayz.... Thanks Foxpaw for that fix code but now I have another problem...

    class RaceCarTire extends BulldogTire;

    defaultproperties
    {
         StaticMesh=StaticMesh'MythTestRaceMeshs.TestWheel'
         DrawScale=50.000000
         CollisionRadius=34.000000
         CollisionHeight=34.000000
         Begin Object Class=KarmaParamsRBFull Name=KParams0
             KInertiaTensor(0)=1.800000
             KInertiaTensor(3)=1.800000
             KInertiaTensor(5)=1.800000
             KLinearDamping=0.000000
             KAngularDamping=0.000000
             bHighDetailOnly=False
             bClientOnly=False
             bKDoubleTickRate=True
             Name="KParams0"
         End Object
         KParams=KarmaParamsRBFull'RaceCarTest.RaceCarTire.KParams0'

That gives me a Error with ut... It compiles fine (expected) but then when I hit the factory trigger... it quits ut and goes to an error message pweese help again !?

Corran: Is it a General Protection fault thing? If so, it could be caused by you doing

    KInertiaTensor(0)=1.800000
    KInertiaTensor(3)=1.800000
    KInertiaTensor(5)=1.800000

instead of

    KInertiaTensor(0)=1.800000
    KInertiaTensor(1)=1.800000
    KInertiaTensor(2)=1.800000

Without any empty elements. Doing that with GUI elements gives a similar error.

MythOpus: Well, i didn't notice it before but I tried it and it still gives the same error...

General protection fault!

History: AKCarWheelJoint:: preKarmaStep <- CallPreConstraintStep <- ProcessPartitions <- KWorldStepSafeTime <- KTickLevelKarma <- TickAllActors <- ULevel::Tick <- (NetMode=0) <- TickLevel <- UGameEngine::Tick <- UpdateWorld <- MainLoop

Corran: What is the exact code you have now? It's possible you need to fill all 6 (0-5) elements of the array.

Foxpaw: Well, I'll go out on a limb and suggest that you probrably shouldn't try to overwrite the template in bulldog tire with one with the same name. KParams0 is already defined in the superclass, bulldogtire, and I don't know how UT2003 feels about you trying to overwrite that.

However, I doubt that's the problem, though it's worth a shot. I would try a serioes of diagnostics to see what's "going down" with that code. I'd try placing a KActor in a map with that static mesh set first, and see if that works. Then I'd take everything out of the racecartire and see if it works then (it should be identical to a bulldogtire at this point) then, start adding things: first try it with only the static mesh changed, then copy and paste the karma parameters from the bulldog tire and start slowly changing things.

Further, the drawscale of 50 seems a bit big, I don't know if your tire was really imported that tiny but if it wasn't imported tiny a giant tire may cause problems with the Karma engine.

MythOpus: Corran: My Tire code is completely Identical to that of the BullDogtire

Foxpaw: I shall try that out and yes, the modeler somehow got it ot be REALLY small so I had to jack up the drawscale

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