====== Futurama Appearance Effect ======

This tutorial will teach you how to create a warp appearance effect like at the start of the Futurama title sequence. The effect will look something like this:

{{ :tutorials:spawners:futurama.gif?direct |}}

In order to make this, you will need three simple things: an object like a ship, a blue spike, and a flat ball:

{{tutorials:physics:ship.png?direct|}} {{:tutorials:spawners:warp-spine.png?direct|}} {{:tutorials:spawners:glow-bubble.png?direct|}}

Begin by creating the alien ship on screen:

<code ini>
[Alien]
Graphic   = AlienGraphic
Position  = (0, 0, 0.5) 
ChildList = WarpAppearance

[AlienGraphic]
Texture = ship.png
Pivot   = center
</code>

Notice the ''WarpAppearance'' object added to the child list. This is where the appearance affects will be added. Whenever an instance of an alien ship is created, a nice appearance effect will show with it.

Define ''WarpAppearance'' with:

<code ini>
[WarpAppearance]
AngularVelocity = 100
ChildList       = WarpSpineMaker 
LifeTime        = 4
</code>

''WarpAppearance'' is just an empty object that is turning. This object will only live for 4 seconds, then it will die. Attached to this (as a child) is ''WarpSpineMaker''. 

Create ''WarpSpineMaker'' with:

<code ini>
[WarpSpineMaker]
Spawner  = WarpSpineSpawner
Position = (0, -3, 0)

[WarpSpineSpawner]
Object          = WarpSpine
ActiveObject    = 40
WaveSize        = 5
WaveDelay       = 0.1
CleanOnDelete   = true
UseSelfAsParent = true
</code>

''WarpSpineMaker'' has a spawner defined (''WarpSpineSpawner''). ''WarpSpineSpawner'' will spawn loads of ''WarpSpine'' objects, which are the blue spike texture as above.

<code ini>
[WarpSpine]
Graphic         = @
Texture         = warp-spine.png
Pivot           = (17, 202, 0)
AngularVelocity = -200 ~ 200
FXList          = FadeInOutFX
LifeTime        = 1.0
</code>

This is the interesting part. Each ''WarpSpine'' object that is spawned by ''WarpSpineSpawner'' has a low centered pivot point and a random spin value. Each only lives for a second, but this gives a "filtered light" effect. To smooth the appearance in and out of each object, a ''FadeInOutFX'' is defined:

<code ini>
[FadeInOutFX] 
SlotList    = FadeInOutFXSlot
KeepInCache = true
Loop        = false
 
[FadeInOutFXSlot]
Type          = alpha
Curve         = sine
StartTime     = 0.0
EndTime       = 4.0
StartValue    = 0.0
EndValue      = 1.0
Absolute      = true 
</code>

Add a small piece of object creation code to your project's ''init()'' function:

<code c>
orxObject_CreateFromConfig("Alien");
</code>

Compile and run. The ship will appear with a dazzling array of blue spines surrounding it.

For a minor enhancement, we'll also spawn some randomly coloured balls to act as a type of lens flare. Change the ''WarpAppearance'' to include a child called ''BubbleCreator'':

<code ini>
[WarpAppearance]
AngularVelocity = 100
ChildList       = WarpSpineMaker # BubbleCreator
LifeTime        = 4
</code>

And it is defined as:

<code ini>
[BubbleCreator]
Spawner  = BubbleSpawner
LifeTime = 3

[BubbleSpawner]
Object           = Bubble
ActiveObject     = 24
WaveSize         = 2
WaveDelay        = 0.1
UseRelativeSpeed = true
</code>

''BubbleCreator'' only lives for 3 seconds in total and has a spawner called: ''BubbleSpawner''. It in turn spawns objects called ''Bubble'':

<code ini>
[Bubble]
Graphic  = @
Texture  = glow-bubble.png
LifeTime = 1
Speed    = (-250, -250, 0) ~ (250, 250, 0);
Scale    = 0.5 ~ 1.0
Pivot    = center
HSV      = (0.0, 1.0, 1.0) ~ (1.0, 1.0, 1.0)
FXList   = FadeAwayFX
</code>

These shoot away in random directions, have a random colour and size. They also fade nicely away with ''FadeAwayFX'', which we'll define here:

<code ini>
[FadeAwayFX] 
SlotList    = FadeAwayFXSlot
KeepInCache = true
Loop        = false
 
[FadeAwayFXSlot]
Type          = alpha
Curve         = linear
StartTime     = 0.0
EndTime       = 0.5
StartValue    = 1.0
EndValue      = 0.0
Period        = 0.5
Absolute      = true
</code>

Run that and the alien will appear in a wash of blue spikey light and coloured flares.