layer of picture on a graph

[labmaster]

As shown in the attachment (test.vi), I generated 33 small circles (in base layer) on a graph in the beginning of VI execution.

I want to change the color of several circles of 33 in one time dynamically depending on the cursor position.

I cannot find any information on layer or delete option in picture function.

Do I need to redraw "all" circles to change the color in several circles? 

or can I use the prepared picture of base layer again by overwriting the base layer?

In this case, no problem in memory eventually?

labmaster.

[Intaris · Accepted solution]

The picture control used is executed iteratively. If you store the value after the circles which don't change, you could theoretically only redraw the "changed" circles.

But this only works if you know the circles which may change from the beginning.