Newbie with a question about how to control an animated knob.

I am making a basic course on how to change out a bottle gas cylinder for lasers we use to cut steel. This is the initial phase: I have 2 vector shapes for the cylinders and a .png knob in between. What I would like to happen is when the cylinder on the right is selected the knob would turn to the right and when the cylinder on the left is selected, the knob would turn to the left. Ideally, the user would be able to do this as often as they would like until they select the Submit button which takes them to the next slide. I have it setup the way I think it should work, but it is not working out. My question is: How would you get this to work? If I have left out vital info, please let me know. This can only help me when trying to communicate in the future.

3 Replies
Walt Hamilton


A first thought is that you can give the knob two states, one with a pointer pointing to the left tank, and the other pointing to the right. Call one state right, and the other left. Set a trigger to change the state of the knob to left when the user clicks on the the left tank, etc.  You won't be able to see it actually rotate, but the pointer will switch sides, giving the illusion of turning. Then you can check the state of the knob to determine if they have turned it the correct direction.

If this isn't clear, or adequate, if you can attach your .story file, someone here may be able to look at it and help you.