MotionPathPlugin - 1D cubic path issue

[swingingtom]

Hi GSAP Team & Contributors,  

 

I've had hard times to make "1D cubic path" working.

According to the following codepen, simply extracting the y property of a working curve data doesn't produce the same tween : 

let points = [{x:0,y:0},{x:50,y:0},{x:100,y:50},{x:100,y:100}]; // Reference Y
let yValues= [{y:0}    ,{y:0}     ,{y:50}      ,{y:100}]; // Not the same tween/smoothing

GreenBall is 2D cubic path, as BlueRect is 1D cubic path using the same values

See the Pen qBPBQQP by swingingTom (@swingingTom) on CodePen

 

A workaround a could have imagine is to tween another fake property in order to have a two-dimensional properties

let points = [{x:0,y:0}  ,{x:50,y:0}  ,{x:100,y:50}  ,{x:100,y:100}]; // Reference Y
let yValues= [{y:0,foo:0},{y:0,foo:50},{y:50,foo:100},{y:100,foo:100}]; // Not the same tween/smoothing

But according to this codepen, it won't work : 

See the Pen NWaWOXX by swingingTom (@swingingTom) on CodePen

 

I start to believe that `type:cubic` require both `x` and `y` property to produce the cubic smoothing.

 

 

For now, my only working workaround is to animate a proxy target, that only reports "y" property on the real target to be animated. 

See the Pen GRMRYav by swingingTom (@swingingTom) on CodePen

 

gsap.to(proxyTarget, {
      duration: 3,
      ease: "none",
      repeat: -1,
      yoyo: true,
      motionPath: {
        path: cubicPoints2D,
        type: "cubic"
      },
      onUpdate: function () {
        gsap.set(realDisplayTarget, { y: proxyY.y });
      }
    }),

 

I know that looks more like I should use CustomEase for the prodived cases, but I would like to know better the cubic motionpath features and its limitations.

 

 

 

 

See the Pen bGoGxQw by swingingTom (@swingingTom) on CodePen

[OSUblake]

Welcome to the forums thom!

 

You might want to change your username so spammers don't find it.

 

I don't think the MotionPathPlugin can currently handle 1D values like that, so I would just feed it the 2D values, and then use the modifers plugin like so...

 

See the Pen dyVyQEm by GreenSock (@GreenSock) on CodePen

 

[swingingtom]

Thanks @OSUblake for the advice, thats the first thing I did after posting.

 

Quote

I don't think the MotionPathPlugin can currently handle 1D values like that

It can according the to scale demo codepen from documentation page : 

See the Pen vYBVQap by GreenSock (@GreenSock) on CodePen

But I guess not in a cubic way.

 

The modifiers plugins seems way better than my workaround.

 

 

[OSUblake]

3 hours ago, swingingtom said:

But I guess not in a cubic way.

 

Yeah, it handles x and y differently for cubic, which is kind of described here.

 

 

All other properties use the smooth algorithm.