Creates a flow path along the current motion path or around the current object.
The lattice created from a Paths > Flow Path Object will ignore effects introduced by any motion path orientation markers. To enhance the front, up, side twist of a path animation with flow, animate the rotation of the flow lattice rather than using orientation markers for the path animation.
Animate > Motion Paths > Flow Path Object > 
These values represent the number of lattice sections that will be created. The Front, Up, and Side correspond to the axes that were specified when the path animation was created.
For example, if the path animation was created with the Front Axis set to Z, and the Up Axis set to Y (in the Attach to Motion Path Options window). The Side Axis is therefore the remaining axis, that is, the X axis. Then, the Divisions: Front will be the number of divisions in the lattice along the Front direction, which in this case will be the object’s Z local rotation axis. Similarly for the Up and Side options in the Divisions section.
This option is most useful when the you create the lattice around the curve. If the lattice is large, you probably don’t want to have the lattice points at one end of the lattice affect the object when it is close to the other end of the lattice.
For example, if the Lattice Around Curve option is chosen, and the Divisions: Front is set to 30, this means that there will be 30 subdivisions of the lattice from end-to-end of the path animation curve. As the object moves through the lattice, it may only be surrounded by 4 or 5 divisions in the front direction at any one time. If Local Effect is off, then all the lattice points in the 30 subdivisions will affect the deformation of the object. This could cause the object to “drift” out of the lattice since it is being influenced by lattice points that are very distant from the object.
The two diagrams below show Local effect for a Lattice Around Curve. In the first diagram, Local effect is on; in the second one it is off.
In general, if Local effect is on, the Local effect divisions should be set to approximately the number of divisions of the lattice that the object will cover.