help with vehicle tyre marks?

[tegleg]

hello
skid mark help please if you have any ideas
im spawning a decal under a car wheel every tick() when its sliding, but it looks like this


any ideas on improving the looks?
like getting a smooth line instead of overlapping squares

atm its just using a grey square MITV set to the rotation of the car
and i cant spawn it any more frequently

thanks for taking a look

[darthviper107]

try using the Ribbon particle type, it'll create ribbons that connect the particles together rather than using planes.

[tegleg]

thanks
tried ribbon particles and they give very odd results, doesnt give a smooth line at all, and it sometimes calculates the 'arc' wrong and it snaps to a straight line.
when you have a high enough spawn rate to look ok, the framerate goes terrible, and it doesnt propperly conform to the ground.

might end up experimenting with the decal a bit more, maybe some kind of rounded tread pattern will look better, doesnt have to be perfect.

[Solid Snake]

Try setting it to the rotation if the wheel bone instead of the cars rotation.

[Racer1]

I know that this is a bit old thread, but Tegleg, did you have any luck with that?

[tegleg]

no i gave up with that a long time ago. it was eating into the framerate when i had a lot of cars (maybe 10 or so), and never looked any good.
and epic fixed their tyre smoke around the same time so i was getting double smoke from my own system and theirs.

[Racer1]

By any chance, do you still have that skidmarks code?

[tegleg]

this is what i have in my vehicle left over from that, most of it is commented out and probably quite experimental.
not sure it will be any use but here you are

var() ParticleSystem SkidTemplate;
var() MaterialInterface SkidDecal;
var float Skidding;
var() float DecalWidth, DecalHeight;
/** How long the decal should last before fading out **/
var() float DurationOfDecal;
/** MaterialInstance param name for dissolving the decal **/
var name DecalDissolveParamName;
//min skidding speed b4 marks are drawn
var() float MinSkidding;

/**
 * Spawn skid mark Effects
 */
simulated function SpawnSkidEffects()
{
	local vector HitNormal, HitLocation, TraceEnd, TraceStart;
	local TraceHitInfo	HitInfo;
	local int i;
	local MaterialInstanceTimeVarying MITV_Decal;
	local vector X, Y, Z;
	local rotator Rot;
	//local vector Direction;
//	local ParticleSystemComponent ProjExplosion;
	//local Actor EffectAttachActor;
	//local MaterialInstanceTimeVarying MITV_Decal;

	if (WorldInfo.NetMode != NM_DedicatedServer)
	{

			// Disabling for the demo to prevent explosions from attaching to the pawn...
//			EffectAttachActor = (bAttachExplosionToVehicles || (UTVehicle(ImpactedActor) == None)) ? ImpactedActor : None;
			//EffectAttachActor = None;
		//	if (!bAdvanceExplosionEffect)
		//	{

				//trace below wheels
		for( i=0; i< Wheels.Length; i++ )
		 {
                Mesh.GetSocketWorldLocationAndRotation(name("WheelEffectSocket"$i), TraceStart, Rot);
                TraceEnd = TraceStart;
                TraceEnd.Z -= 100;

                Trace(HitLocation, HitNormal, TraceEnd, TraceStart, True,, HitInfo,);
                // smoke
                 if (SkidTemplate != None)  // && EffectIsRelevant(Location, false, MaxEffectDistance) ProjExplosionTemplate
	            	{
                          WorldInfo.MyEmitterPool.SpawnEmitter(SkidTemplate, HitLocation, rotator(HitNormal));
                        }

               if( MaterialInstanceTimeVarying(SkidDecal) != none )
					{
                                             //texture left on the floor
						MITV_Decal = new(self) class'MaterialInstanceTimeVarying';
						MITV_Decal.SetParent( SkidDecal );

                        GetAxes(Rotation, X, Y, Z);

						WorldInfo.MyDecalManager.SpawnDecal(MITV_Decal, HitLocation, rotator(-HitNormal), DecalWidth, DecalHeight, 10.0, FALSE, (Rot.Roll * UnrRotToDeg) );  // ( Rotation.Yaw * UnrRotToDeg)
						//here we need to see if we are an MITV and then set the burn out times to occur
						MITV_Decal.SetScalarStartTime( DecalDissolveParamName, DurationOfDecal );

		             }



        //	}
		/*	else
			{
				Direction = normal(Velocity - 2.0 * HitNormal * (Velocity dot HitNormal)) * Vect(1,1,0);
				ProjExplosion = WorldInfo.MyEmitterPool.SpawnEmitter(SkidTemplate, HitLocation, rotator(Direction), EffectAttachActor);
				ProjExplosion.SetVectorParameter('Velocity',Direction);
				ProjExplosion.SetVectorParameter('HitNormal',HitNormal);
			}        */
			//SetExplosionEffectParameters(ProjExplosion);

		//	if ( !WorldInfo.bDropDetail && ((ExplosionLightClass != None) || (ExplosionDecal != none)) && ShouldSpawnExplosionLight(HitLocation, HitNormal) )
		//	{

				// this code is mostly duplicated in:  UTGib, UTProjectile, UTVehicle, UTWeaponAttachment be aware when updating
			/*	if (ExplosionDecal != None && Pawn(ImpactedActor) == None )
				{
					if( MaterialInstanceTimeVarying(ExplosionDecal) != none )
					{
						// hack, since they don't show up on terrain anyway
						if ( Terrain(ImpactedActor) == None )
						{
						MITV_Decal = new(self) class'MaterialInstanceTimeVarying';
						MITV_Decal.SetParent( ExplosionDecal );

						WorldInfo.MyDecalManager.SpawnDecal(MITV_Decal, HitLocation, rotator(-HitNormal), DecalWidth, DecalHeight, 10.0, FALSE );
						//here we need to see if we are an MITV and then set the burn out times to occur
						MITV_Decal.SetScalarStartTime( DecalDissolveParamName, DurationOfDecal );
					}
					}
					else
					{
						WorldInfo.MyDecalManager.SpawnDecal( ExplosionDecal, HitLocation, rotator(-HitNormal), DecalWidth, DecalHeight, 10.0, true );
					}
				}  */
		//	}
		}

	/*	if (ExplosionSound != None && !bSuppressSounds)
		{
			PlaySound(ExplosionSound, true);
		}    */

	//	bSuppressExplosionFX = true; // so we don't get called again
	}
}

[Racer1]

Thanks. I will take a look at it.

[tegleg]

no probs.
a ribbon particle system got the best looking results but sometimes they would spaz out and stretch like an elastic band or string and made straight lines, if the car spins 360 for example.

[exittoexist]

Would it be too much to ask for someone to share the ribbon particle they created for the skidmarks? Thanks