Jumping i Y when moving in X?

[Dan Ebberts]

You could try something like this:

freq = 0.5;
amp = 15;
x = value[0];
y = amp*Math.abs(Math.sin(x*freq*Math.PI*2));
value + [0,y]

The problem is that when the character stops, the odds are that it will be above the “ground”, but it seems to work pretty well while the character is moving.

Dan

[Martin Löfqvist]

Hi Dan,

it works. Sort of.
First of I’m looking to seperate the position dimensions. (It should just be a matter of re-arranging the code I think).
Then it behaves kinda odd when I’m changing the incoming/outgoing velocity of the keyframes. Whys that?

[Dan Ebberts]

Basing it on horizontal distance traveled (like the tutorial) probably doesn’t work for this. You might be better off basing it on time. Here it is set up for separated y position:

freq =2;
amp = 15;
y = amp*Math.abs(Math.sin(time*freq*Math.PI*2));
value + y

Dan

[Martin Löfqvist]

Yeah,

this is nice! Is it possible to run this only when the object is moving in x? Is it possible to get the last frames x position and compare it to the current frames x position? That way you could get that information.

[Dan Ebberts]

More like this maybe:

if (transform.xPosition.speed > 0){
freq =2;
amp = 15;
y = amp*Math.abs(Math.sin(time*freq*Math.PI*2));
}else
y = 0;
value – y

Dan

[Martin Löfqvist]

Dan, amazing! This seems to work.

Very much appreciated!!

A question regarding the solution:
1) You are analyzing the “speed” property in xPosition. Is this the same value as you see in the graph editor? (Had no idea you could get this value!)

2) You are writing “value – y”, is value a variable or a way to … execute the script? I never seen it before.


[Dan Ebberts]

>Is this the same value as you see in the graph editor?

It should be.

>is value a variable

“value” is just shorthand for the pre-expression value of the property hosting the expression. In this case it would be the same as using “yPosition”.

Dan

[Martin Löfqvist]

Ah I see!

One, not so tiny problem though:
Because it’s based on the xPosition.speed moving it to the left renders a negative speed value thus no jumping.
Would the solution be just to look for the exact value of 0 in xPosition.speed or writing another if loop?

[Martin Löfqvist]

I solved it by changing > to !== in the if loop,

thanks for the help Dan!

if (transform.xPosition.speed !== 0){
freq =2;
amp = 15;
y = amp*Math.abs(Math.sin(time*freq*Math.PI*2));
}else
y = 0;
value - y


[Dan Ebberts]

It would be != not !==.

Dan