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Link position to scale expression ?

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Lucas Piazzini
Link position to scale expression ?
on Apr 14, 2020 at 12:49:16 pm

Hello guys ! First of all hello, this is my first post here ☺

I am doing a bouncing ball animation with expressions and would like to create it's shadow. I'd like to make it scale based on the ball's height (position, more generally), but I am quite running out of ideas to transcribe it's height into a %.. I need help please !

Thank you for the answers in advance =)


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Andrei Popa
Re: Link position to scale expression ?
on Apr 14, 2020 at 2:22:34 pm







Andrei
My Envato portfolio.


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Lucas Piazzini
Re: Link position to scale expression ?
on Apr 14, 2020 at 2:23:20 pm

Thank you very much !


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Lucas Piazzini
Re: Link position to scale expression ?
on Apr 14, 2020 at 6:23:14 pm

After hours of headaches and with the help of my Data scientist father, I was able to make a much simpler and versatile version that revolves around no other constant than a factor unlike school of motion, it also allows you to control the speed of evolution from minimum scale to maximum scale, aswell as the minimum scale ! Thanks for your help I wouldn't have improved without your link !

Factor = 20 //Control the scale variation, smaller factor = smaller minimum size

var diameter = thisComp.layer("Ball").content("Ellipse 1").content("Ellipse Path 1").size[1];
var ball_yPos = thisComp.layer("Ball Pos").transform.position[1];
var ground = thisComp.layer("Ground").transform.position[1];
var hDepart = diameter*2; //Control the scale speed
var diff_BallGround = ground - ball_yPos;

if (diff_BallGround<hDepart){ //Shadow Scaling
substract = (diff_BallGround/Factor)
}else{
substract=hDepart/Factor // Minimum size
}

if (substract&lt;0){ //To prevent the shadow from getting larger
substract = 0
}


[100-substract,transform.scale[1]]


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Scott McGee
Re: Link position to scale expression ?
on Apr 14, 2020 at 2:28:11 pm

This is kind of what you want. I don't have anything that caps it at a percentage, but hopefully it'll get you started.

posTwo = thisComp.layer("Shape Layer 2").transform.position.key(1).value[1];
currentPos = thisComp.layer("Shape Layer 2").transform.position[1];

x = transform.scale[0] - (100 - (currentPos/posTwo)*100);
y = transform.scale[1];
[x,y]


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Scott McGee
Re: Link position to scale expression ?
on Apr 14, 2020 at 2:28:44 pm

Just seen Andrei has answered you, hahaha. So ignore me.


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