Apple Motion 4 - Manual (Page 636)

Start Point: This parameter becomes available when Shape is set to Line or Wave. Two
sliders that define, in X and Y coordinates, the first point of the line used as the emitter
shape. Click the disclosure triangle to modify the Z position of the start point. You can
adjust these values in the Canvas using the onscreen controls (with the Adjust Item tool).
End Point: This parameter becomes available when Shape is set to Line or Wave. Two
sliders that define, in X and Y coordinates, the second point of the line used as the emitter
shape. Click the disclosure triangle to modify the Z position of the start point. You can
adjust these values in the Canvas using the onscreen controls (with the Adjust Item tool).
Emit At Points: This checkbox is available when any of the following is chosen in the
Shape pop-up menu: Line, Rectangle (with Arrangement set to Outline or Random), or
Circle (with Arrangement set to Outline or Random), Burst, Spiral, Wave, Geometry, Box
(with Arrangement set to Outline), Sphere (with Arrangement set to Outline). When the
Emit At Points checkbox is selected, particles emerge from a limited number of points
(as defined in the Points parameter). When the checkbox is deselected, particles may
emerge from anywhere on the line or edge. When the Adjust Item tool is selected, the
points are visible in the Canvas. When Emit At Points is selected, two additional parameters
become available: Point and Offset.
Points/Points Per Arm: This parameter is available when any of the following is chosen
in the Shape pop-up menu: Line, Rectangle, Image, or Circle (with Arrangement set to
Outline or Random Fill), Burst, Spiral, Wave, or Geometry; in addition, the Emit At Points
checkbox must also be selected. Defines the number of points from which particles are
emitted. For Rectangle or Circle shapes, the particles are emitted from evenly distributed
points along the edge of the shape when Outline is chosen from the Pattern pop-up
menu. When the Adjust Item tool is selected, the points are visible in the Canvas.
Keep in mind that using a large number of points slows your computer’s processing time.
Radius: This parameter is available when one of the following is chosen in the Shape
pop-up menu: Circle, Burst, Spiral, or Sphere. Defines the size of the shape from which
particles are emitted.
Twists: This parameter, available when Spiral is chosen in the Shape pop-up menu, defines
the number of turns in the spiral. The default value is 0.25.
636 Chapter 11 Working with Particles