[William Marler]

Firstly, find out where on the X axis you want the Null to begin (i.e. the position of the null where the shape is at normal scale) and note that down (I’ll refer to it in the code as “A”)

In the scale property of your path, type the code below.

Hope this does the trick.

x = (thisComp.layer("insert the name of the null here").transform.position[0]-A)+100;

y = transform.scale[1];

[x,y]

[William Marler]

Ah nice, apologies for not being able to solve the problem myself, but it’s good that you were able to work it out anyway.

William

[William Marler]

Ah yes I see the problem. Based on the reference image you provided, I only assumed the hands would change on the Y axis, which is why the Plexus only scales on that axis and doesn’t at the start. I shall revisit this thread tomorrow morning and have a look at how to incorporate X also.

William

[William Marler]

Yep, it works perfectly now.

[William Marler]

Hi Michael, I have worked out how to do it.

Add a slider to the Plexus ball and add this code to it (first expression listed below):

Then, scale up the Plexus ball so its top and bottom points are where you want on the lady’s hands and write down the scale value of this desired size. Also write down the value of the expression slider at this frame.

Now in a calculator app find out the value of (slider value you noted down)/(scale value you noted down) and write that down.

Open the scale property on the Plexus ball and copy and paste this expression into the value (second expression listed below):

Hope this works and if you struggle with my explanation, I can provide a project file for reference.

William

Expression 1
thisComp.layer("name of your bottom null").transform.position[1]-thisComp.layer("name of your top null").transform.position[1]

Expression 2
temp = effect("Slider Control")("Slider")/10.8;

[temp,temp]

[William Marler]

If you create a slider on a control layer, and pick whip the time remap to that slider, the slider value will be equal to the frames of the time remap.

For example, when the slider = 0, time remap will be 0:00:00:00, when the slider = 25, time remap will be 0:00:01:00 (if you work at 25fps).

So connect these two values together with the pick whip and animate the slider going from value 0 to value X. Then by moving the value X keyframe, you are altering where the end frame is placed in the timeline.

Hope this helps.

[William Marler]

Ahh, that’s quite elegant actually. So you you string them together with if1, else1-if2, else2-if3, else3-if4, and so on? 🙂 Thanks for your speedy response.

[William Marler]

Hi Göran,

If the mask is simply a line that you want the start and end moving with another layer, then go to Effect>Generate>Beam, and pickwhip the start or end point to your other layer.

If it’s a mask you need because it is a complex shape, I am not sure, but I will keep looking.

Hope this helps!

[William Marler]

Just in case you are interested, I have achieved the effect slightly differently by adding three slider controls to the shape layer, to control R, G, and B respectively, and divided their values by 255, so now I can dial in the 255 RGB values to each individual slider. Thanks again!

[William Marler]

Thank You Darby! Much appreciated, it’s always satisfying to link effects to sliders. 🙂