A procedural animation that is based on Greg Stirling's Kinetic Sculpture, Seagull.
The mechanics of this sculpture mainly consist of two 2-point constraints (red and blue) and two spinning gears.
The math in each point wrangle is similar but the red constraint is on the y axis rather than the x axis. The outer points on the red constraint attach to points on the blue constraint so that if it’s adjusted, everything stays connected unless something is stretched further than it can reach. Also, the rotation of each piece is very important and was very challenging.
The gears are set up to rotate on the z axis at $F * ch(“../speed”) which is one of my top level parameters that makes the speed easily changeable.
Most pieces are being mirrored to create the second wing. The gear is not being directly mirrored because it must fit with the other gear.
To create a gear, I made a tube with 150 columns around it. I selected every other face with the group range node and extruded them to create the ridges.
To create the second gear, I duplicated the gear and offset the range by 1 in the group range node to select the faces that weren’t selected on the first gear. After that adjustment I mirrored the second gear, causing the two to interlock perfectly when rotating.
More info about setting up this 2 point constraint can be found here.
I added a few top-level controls on the wings to let the user change the sculpture a bit:
X Y Wing Pivot Loc: Lets the user control the x and y location of the top corner where the red and blue point constraints are connected (editable point circled below).
Defaults: x = 3.6, y = 3.7
New Values: x = 5.542, y =1.44
Gear Width: Lets the user make the gears thicker or thinner.
New Value: 10
Gear Radius: Controls the radius of the gears (X Y Wing Pivot Loc may need to be adjusted along with the gear radius so the wings still work).
New Value: 0.38
Bottom Horizontal Length: Controls the length of bottom horizontal bar (highlighted in red), which controls how the outer wing flaps (often needs adjusted when the X Y Wing Pivot Loc or Gear Radius is changed).
New Value: 1.13
Speed: Controls the speed that the gears spin, making the wings faster or slower. Default: 3