...
“Anti-parallel” is a term you will come across quite often in the following descriptions. From a user's perspective, these faces and polygons appear as parallel, but there is one difference: the normal's of the polygons have opposite directions as shown in the image below:
MultiJoints - Tutorials
- A Crane
- Door Hinges
- Path Follow Constraint (Moving an Object over a RealWave Surface)
- Wrecking Ball