Graphics Reference
In-Depth Information
Figure 6-8
Velocity and Rotation panels
The Velocity panel enables you to set the direction that the particles are initially emitted in. The possible
directions include the following:
Normal
Normal indicates the direction of the surface normals of the emitter mesh. With this value set,
particles will emit from the surface of the mesh directly outward. This is good for sparks and explosions and
is useful for working with hair.
Tangent
Tangent sets velocity tangential to the surface of the object. This indicates velocity perpendicular to
the surface normals of the object's faces. The exact direction of the velocity is indicated by the Rot value.
Rot
Rot (short for “Rotate”) indicates which direction, perpendicular to the surface normals of the object's
faces, the Tan valued velocity actually moves in.
Emitter Object X/Y/Z
Emitter Object X/Y/Z indicates directions along the x-, y-, or z-axis of the emitter
object.
Object
Objectindicatesthedirectionthattheemitterobjectismoving.Ifthisvalueissetasaninitialvelocity,
particles will move in the direction that the object is moving at the time they are emitted. If the object's dir-
ection or velocity changes, the particles will maintain the impetus of the movement the object had when the
particles were emitted. A spray of bullets from the guns of a fighter plane is a good example of this kind of
movement.
Random
Randomindicatesvelocityinarandomdirection.Whenthisvalueisset,particlesmoveinarandom
direction outward from the mesh.
