2009

Limiting Rotational Joints

Limits for a rotational joint define how far the object can rotate about its

parent’s axes. The values in the From and To fields represent the rotation

angle about the active axis measured from 0 degrees on the parent object.

For example, an elbow joint rotates the forearm with respect to the upper arm.

In the figure the limits on X axis rotation are from 0 to 135 degrees. The Y, Z

axes are inactive because an elbow joint rotates about a single axis.

Limiting Sliding Joints

Limits for a sliding joint define how far a joint can move along its parent’s

axes. The values in the From and To fields represent a distance for movement

along the active axis measured from the pivot point of the parent to the pivot

point of the selected object.

For example, a sliding joint on a piston moves the piston in and out of the

cylinder. In the figure, the limits on Z axis movement are from 10 to 90. This

prevents the piston from hitting the bottom or moving past the end of the

cylinder.

Limiting Path and Surface Joints

Limits for path and surface joints define how far along the path or surface an

object can move. The values in the From and To fields represent a percentage

of the total distance measured along the path or surface.

For example, a path joint for a house key moves the key along a key ring.

Setting the limits on the path joint at 5% to 95% prevents the key from

traveling along the ring where the fob is attached.