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guides:beginners:timeline_tracks

Part 17 - Timeline Tracks

We could set up a spawner to create a load of monsters for us, but we'll use a timeline instead. A timeline can issue commands.

Our timeline will simply issue the same create object command over and over in a loop.

Before we do this, remove the single monster from the Scene. We don't need it any more:

[Scene]
ChildList = PlatformObject # MiddlePlatformObject #
TopLeftPlatformObject # TopPlatformObject #
TopRightPlatformObject #
StarObject

Now to create a simple track:

[MonsterMakerTrack]
1    = Object.Create MonsterObject
Loop = True

This will create monsters over and over every second for us. But the monster objects need to start at a random position each time. Change the monster object to have a range of starting x positions:

[MonsterObject]
Graphic      = MonsterGraphic
AnimationSet = MonsterAnimationSet
Position     = (20, 0, 0) ~ (600, 0, 0)
Scale        = 2.0
Body         = MonsterBody

Finally, to actually use the track which will create monsters, add it to the TrackList property in the Scene section:

[Scene]
ChildList = PlatformObject # MiddlePlatformObject #
TopLeftPlatformObject # TopPlatformObject #
TopRightPlatformObject #
StarObject
TrackList = MonsterMakerTrack

Looking great! Monsters should be dropping in all over the place:

Some tweaks can be added to the monster and the body to improve things a little:

[MonsterObject]
Graphic      = MonsterGraphic
AnimationSet = MonsterAnimationSet
Position     = (20, 0, 0) ~ (600, 0, 0)
Speed        = (-20, 0, 0) ~ (20, 0, 0)
Scale        = 2.0
Body         = MonsterBody
 
[MonsterBody]
Dynamic            = true
PartList           = MonsterBodyPart
AngularDamping     = 50
LinearDamping      = 0.2
 
[MonsterBodyPart]
Type        = box
Solid       = true
SelfFlags   = monster
CheckMask   = hero # platforms # bullet
Friction    = 0
Restitution = 0.2
Density     = 20

The Speed on the object will give the monsters a little random left/right movement. The Friction on the bodypart will make the monster less slippery on the ground.

The LinearDamping on the body will slow him down a little over time if he's too fast. The high AngularDamping will ensure the monster tips over the edge but not rotate and tumble wildly.

Finally, a touch of Restitution on the body will allow it to bounce just a touch when landing from a height.

That should work a little better.


Next: Part 18 – Exploding Monsters.

guides/beginners/timeline_tracks.txt · Last modified: 2017/06/13 04:20 (4 months ago) by sausage