SpiderCam
Geometry & Trigonometry
Work out the cable lengths that place a stadium SpiderCam at any point above the pitch, using 3D coordinate geometry.
Where this idea comes from
Start here — this is the source that inspired this exploration.
Introduction
A SpiderCam is a camera suspended from four cables running to motorised winches at the top of each stand of a stadium. By shortening or lengthening the four cables, the camera can be moved to any point above the pitch. This exploration treats each cable as the distance from a winch position to the camera's 3D coordinates, and asks you to work out the cable lengths needed to place the camera at a chosen point, and to plan how those lengths must change over time for a smooth camera move during a replay.
Guiding Questions
- A SpiderCam hangs from four cables. How does changing the cable lengths move the camera?
- Set up 3D coordinates for the four pylons and express the camera position from cable lengths.
- Solve the inverse problem: what lengths place the camera at a chosen point above the pitch?
- Plan a smooth camera path for a replay and compute how each cable must change over time.