Piecewise Activity

This isn’t exactly a CL question, but I didn’t have any luck on the Desmos Facebook group.

I am wanting students to be able to graph a piecewise function by “plotting points,” then clicking an action button to check their work. If their points are in the right place the button causes an animated “connect the dots.” I have the CL working for the graph animation, but I am stuck on getting the point to be both open and have vertical drag. Is it not possible? And if not, any ideas for a workaround? (The points are currently “layered” from left to right.)

Please see screen 3 of this activity: https://teacher.desmos.com/activitybuilder/custom/61f438851618e2329ee1e3ad

The reply you got from Elayna MG was correct: create your draggable point as normal, then create a non-draggable point with the same coordinates. For example, P=(2,a) to create your vertically draggable point and then P_1=P to create a point you can stylise however you want - open circle, change the size, etc.

Once done, if you reduce the opacity of the draggable point to 0, it is invisible but still movable - so it ‘feels’ like you’re moving the open circle.

Essentially this:

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Thank you! The opacity detail is what I was missing. And now it makes perfect sense. Thank you so much!