Make actors grow / shrink according to distance from any given point?

Loaded

I need to try and resize an actor from 15 to 40 (width and height) over any given distance from another actor (emitter), I would like to avoid using interpolate and so far have the actor resizing using magnitude...

magnitude(self.Position.X-emitter.Position.X,self.Position.Y-emitter.Position.Y)

This is great (Thanks @RThurman ) but I want the actor to grow from size 15 to size 40 during its journey from the emitter to it's final position. It's worth noting that the final position is a random(x,y).

Anyone got any ideas?

Thanks, Loaded.

Loaded

My illogical brain is thinking that the logic I need is the magnitude between emitter and final position and the magnitude between 15 and 40, then smush them together into one expression to unite the kingdoms!!!

RThurman

@Loaded -- There are probably several different ways to do this. Here are two;

1) you could use the min and max functions

max(15,min(40,magnitude( game.emitterX - self.Position.X , game.emitterY - self.Position.Y )))


2) or you could use a formula that wont go below 15 but will keep the actor growing so that it reaches 40 when it is about a screen length from the emitter

15+magnitude( game.emitterX - self.Position.X , game.emitterY - self.Position.Y )*.05

The ".05" is a multiplier that you can mess with till you get the growth rate you want.

RThurman

Oops... just realized you want to sent the actor to a random location.

In that case, the first thing you will need to do is get the initial distance between the actor and its final position:
Change Attribute: self.InitialDistance To: magnitude(self.finalX - self.Position.X , self.finalY - self.Position.Y)


Then the size formula would look something like:
Constrain Attribute: self.size.width To: 15+(self.InitialDistance - magnitude(self.finalX - self.Position.X , self.finalY - self.Position.Y ))*((40-15)/self.InitialDistance )

Loaded

Only just got around to playing with your answer @RThurman

Works perfectly, thanks

maRaider

I am trying a variant of this that is not working and am unsure why. I am trying to get an object to scale based on how close to a point the player is. (This is a gravity meter that is supposed to grow as you approach the target object) I am attempting to set up a formula that puts the magnitude in a min/max formula in the denominator

But when I do this, the object does not draw at all.

It appears and scales (inverse to how I want it to) when there is no additional math involved, but as soon as I try to modify that magnitude calculation with any other calculations, it just stops working entirely.

Suggestions welcome. This is a polish feature, and not crisis-worthy, but I would really like to know why it is not working.

RThurman

When it stops working entirely, it often means there is an error in the expression. It might be missing some need parentheses, or perhaps a function was typed in (instead of using the function menu), or perhaps a comma is missing.

What are you doing when you "try to modify that magnitude calculation"?