I had a couple of spare projectors at church and decided they if they were set up to cover the whole stage area would work quite nicely as a followspot, just by having a screen with white dots on it moving to cover the necessary area. I couldn't find anything to do this (though there's some nice effects software that doubles as a gobo).
This is a very simple javascript web page to cover the need. Load it up, set it to fullscreen and off you go.
- The active spot is moved by the mouse and adjusted with the keyboard.
- There are 10 spots in total. Switch between them using the number keys
- 1 is the only visible spot at startup
- They are layered 0 (bottom) to 9 (top) if they overlap
- v toggles visibility
- r, g & b increase the RGB values
- R, G & B (so, shift+RGB) decreases the RGB values
- + & - increase and decrease the size of the spot.
- Add transparency adjustment for when they overlap.
- Add ability to change shape (and draw the new shape, obviously)
- maybe switch move to when mouse is over a shape and clicking?