How to set the position of an effect?

[The Czar]

I feel really stupid but for the life of me I cannot figure out how to set the position of effects on the screen. I have tried all kinds of set this and that methods but after the initial placement, it remains fixed on the screen. I’m trying to integrate it into an existing game engine, so I need to control these things manually. How can I do something like this?

Local effect:tlEffect
While Playing
effect.SetPosition(x, y) ‘different every frame
effect.Draw()
Flip
Wend

[imported_peterigz]

Hello, your example is basically how you would do it.

Taking the sample code from this site, to move the effect around with the mouse you could do:

SuperStrict



Import rigz.timelinefx

Import rigz.tweener



'Load the effects library

Local MyEffectsLib:tlEffectsLibrary = LoadEffects("effects/examples.eff")

'Create an effect and assign it an effect from the library

Local MyEffect:tlEffect = MyEffectsLib.GetEffect("simple explosion 1")

'Create the particle manager to manage the particles

Local MyParticleManager:tlParticleManager = CreateParticleManager()



Graphics (1024, 768, 0)



'These commands are important to set the origin of the particle manager. For this example we're setting the origin so that

'effects will be placed at screen coordinates. If you leave out the setorigin command then an effect created at 0,0 would

'be placed at the center of the screen.

myparticlemanager.SetScreenSize(GraphicsWidth(), GraphicsHeight())

myparticlemanager.SetOrigin(GraphicsWidth() / 2, GraphicsHeight() / 2)



'This will make one frame equal 33 millisecs long - or 30 updates per second.

SetUpdateFrequency(30)



'Create a tweener using the tweener mod. Make sure its frequency matches that above

Local Tweener:tTweener = New tTweener.Create(30)



local mouseeffect:tleffect



'Our main loop

While Not KeyDown(KEY_ESCAPE) Or AppTerminate()



Cls



If MouseHit(1)

'to create an effect you need to use the copyeffect command, and copy the MyEffect you created earlier.

'You shouldn't use MyEffect as it is the template

'for which is used to create effects you draw on screen.

Local tempeffect:tlEffect = CopyEffect(myeffect, MyParticleManager)

'Set the temp effect to the mouse coords

tempeffect.setposition(mousex(),mousey())

mouseeffect=tempeffect

'add the effect the the particle manager. Important, otherwise the particle manager would have nothing to update

MyParticleManager.addeffect(tempeffect)

End If



'here is the timing code, update the tweener to get the number of ticks for this loop

Tweener.Update()



For Local Ticks:Int = 1 To Tweener.FrameTicks

'Update the execution time for the tweener

Tweener.UpdateExecutionTime()

'Update the particle manager

if mouseeffect mouseeffect.setposition(mousex(),mousey())

MyParticleManager.Update()

Next



'and finally draw the particles.

MyParticleManager.DrawParticles(Tweener.Tween)



Flip 0



Wend

That’s just a very rough example, but is basically what you’d have to do. You can also download the vaders source code from the downloads page for some more insights, for example the bullets are effects that are moved about the screen.

[The Czar]

I’ve tried all that and it doesn’t work 😥

Here is the code that sets the position:

If _effect Then _debugtext = "effect"

?Debug

If _debugtext.Length > 0

DrawText _debugtext, pos.x, pos.y

End If

?



If _effect

_effect.SetPosition(pos.x, pos.y)

End If

The debug text appears at the correct position on the screen, but the effect never moves from its starting point. I’ve got all the particle managers and tweeners and stuff doing their thing. What’s wrong???

[imported_peterigz]

Can you attach the specific effect you’re trying to move about? I think the only thing I can think that might be causing a problem is if you are using an effect that has a single particle but it’s not as relative so therefore it wouldn’t move about with the effect.

If you can send the effect though I could do a little example with it.

[The Czar]

I think I’m a bit closer to the problem. When I tell an explosion to change position, it can leave trials of effects as it moves. But I’m using SetPosition to move it accross the screen as I scroll around the map – the explosion isn’t physically changing position. What’s the best way to change the position of an effect on the screen without the effect thinking it is moving?

[The Czar]

[attachment=0:33yzb981]Screen2181.jpg[/attachment:33yzb981]

This screenshot shows what I mean. I scrolled to the side and it made the water flow like that, when it should still go up in a straight line.

[imported_peterigz]

Ahh I see. Then I think you need to look at the ParticleManager.SetOrigin(x,y) command. You can change the origin of particle managers specifically so that you can move effects about with your camera.

So just set the origin of the particle manager to match your camera coordinates and all particles drawing will be offset by this.

[The Czar]

Ok I’ve got it working now, thanks!

Another question: I have an engine trail effect from a rocket. As the effect is attached to the rocket, when the rocket hits its effect is deleted and the effect stops suddenly, which looks bad. So I’ve made a list of dying effects and when an object dies, it puts its effects into that list. I want effects in that list to fizzle out and then remove when they are finished. How could I go about doing this? How do I tell an effect to die, and check when it is dead?

[imported_peterigz]

You can use effect.SoftKill() which tells it to stop spawning particles allowing any existing particles belong to the effect to just dying out.

[The Czar]

OK thanks that’s working now.

Is there a way to flip between compiled mode? I would like to turn off compiled mode sometimes to load quicker for a test. Does it have a significant impact on loading speeds?

[imported_peterigz]

To switch a particle manager to use interpolated mode you can call MyParticleManager.SetUpdateMode(tlUPDATE_MODE_INTERPOLATED) and do MyParticleManager.SetUpdateMode(tlUPDATE_MODE_COMILED) to set it back. And when you load in effects set the compile parameter to false so that it doesn’t compile. I noticed though that there’s a bit of code to do with how it loads in the shapes that can be optimised quite a bit, so I might try and sort that out. It’s mainly only loading in shapes with a lot of frames of animation that is the main reason it can be slow sometimes.

[The Czar]

Thank you, you are really very helpful. When I sell my game I will definately make a donation for you. 😀

Another question. I want to create a tesla coil weapon like in Red Alert games. Can I do this with Timeline FX? It means I will need two points, the orb of the coil and the target. Can that work? Thank you.

[The Czar]

With this code

	Function Load()

particle_manager.SetScreenSize(TSettings.resolution_x, TSettings.resolution_y)

particle_manager.SetOrigin(TSettings.resolution_x/2, TSettings.resolution_y/2)

particle_manager.SetUpdateMode(tlUPDATE_MODE_INTERPOLATED)



For Local dir:String = EachIn LoadDir("DataEffects")

If Not _effects.Contains(dir) Then _effects.Insert(dir, LoadEffects("DataEffects" + dir, False))

Next





SetUpdateFrequency(15.0)

Tweener = New tTweener.Create(15)

End Function

I get a Null object error here

'

Speed

If Not bypass_speed

e.speed = c_velocity.changes[0]

e.velvariation = Rnd(-current_speedvariation, current_speedvariation)

e.basespeed = (current_speed + e.velvariation) * parentEffect.currentvelocity

e.velseed = Rnd(0, 1.0)

e.speed = c_velocity.changes[0] * e.basespeed * c_globalvelocity.changes[0]

[imported_peterigz]

It’s been a while since I tested interpolated mode so I will fix that tonight, thanks for the example!

[imported_peterigz]

I’ve fixed this and updated the SVN if you can grab it from there. Seemed to be working ok in the tests I made.

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