The new Path blur filter enables blurring along a motion path. The video below demonstrates how to choose the direction and speed of the blur, refine tapering and even distort the shape of the blur to add artistic effects. You’ll also see how to add more than one path for additional control of the motion.
And here are some shortcuts for the Path Blur Filter:
• Command click the end of a path to set the End Point blur to 0 (zero).
• Shift -drag on the Blur Shape path to simultaneously change the direction of both Blur Shapes.
Duplicating and moving a path
• Command -click (Mac) | Control -click (Win) on the blue path or points to move a path.
• Option + Command -click (Mac) | Alt + Control -click (Win) to copy a path.
• Option -click (Mac) | Alt -click (Win) on a blue path curve point to convert it to a corner point (and vice versa).
Tip: an effective way to visualize what the path blur is doing is to make a white layer with a grid of black dots spaced about 50 pixels apart. Those dots turn into streaks that reveal what the blur shape is in local areas.