Wheel

This video is part of the official comprehensive video course about Duik Ángela

The Wheel automates the rotation of layers according to their translation¹.

Design for Four Wheel Dog Cart, no. 3928,
Brewster & Co., Herman Stahmer, 1884
Public domain.

1. Select the layers.
2. Click the Wheel button

Effect

The Wheel can be adjusted in the effects of the layer.

The Radius is automatically set by Duik, but in some specific cases Duik may not be able to measure it accurately. In this case, you’ll have to set te correct value for the wheel to rotate at the right speed.

If ever you need to animate a wheel rolling on the ceiling instead of the floor, check the Reverse option…

Set the Trajectory according to the type of trajectory followed by the wheel. Be careful, this can greatly reduce the performance.

• Horizontal works only if the wheel rolls on a (almost) horizontal plane.
  In this case, Duik just uses the X Position of the layer to get the traveled distance. This has the best performance as it’s a simple subtraction.
• Straight works if the wheel follows a (almost) straight line.
  In this case, Duik gets the length of the segment between the starting and ending points as the traveled distance. This is a bit slower than the Horizontal option but the difference should not be noticeable in most cases.
• Curved works in all cases.
  This has the worst performance: for each frame of the composition, Duik adds the traveled distance from the previous frame; it’s a cumulative expression. On long compositions, it can be very slow to compute³.

When using the curved mode and you need motion blur, you may increase a bit the Motion Blur Precision value to fix motion blur artifacts, but be careful as this will make the performance drop drastically⁴.