Apple Motion Tip: Setting Precise Widget Snapshot Values

Tuesday, 08 August 2017

In 2011, Apple updated Motion to version 5. It's biggest new feature is the ability to make plugins for Final Cut Pro X. Part of that feature is the ability to control multiple parameters in Motion with a single slider. You can set the start and end values for the slider. Each Motion parameter value you 'rig' to the slider 'widget' can be controlled by the slider. 

In this case, a Slider widget has been to control the width of a line and the font size of some text in Motion. The range of the slider has been set to a minimum of 6 and a maximum of 100:

You can also make it so when the slider is set to a specific value, the rigged parameters can be set to values of your choice. These specific slider values are known as 'snapshots.' In the case above, I would like to make it so a value of 50 for the slider makes the width of the line 10 points and the size of the text 50 points. The problem is that you add snapshots to slider widgets by double-clicking below the slider. You can then drag the snapshot to the value you want it to be, but it is hard to set the value precisely. In this case, the closest I could get the snapshot to be was 50.03.

Before version 5.3, to set a precise value for a snapshot required doing some calculations and opening the Motion file in a text editor and editing the source directly (setting the snapshot value to 0.531914894 (50/(100-6))). I wrote about this back in 2011.

Now all you need do is double-click the snapshot pin. A field appears that you can edit:

Sadly there is a small fault in that the value doesn't take the start value of the slider into account. In this case it doesn't show ‘50.03’ but ‘44.03.’ If you edit this value to be ‘44’…

…the snapshot value is set to ‘50’.

Much easier than before.