User Manual

Table Of Contents
The Region tab is common to almost all particle nodes. In the pEmitter node Emitter Regions
are used to determine the area where particles are created. In most other tools it is used to
restrict the tool’s effect to a geometric region or plane. There are seven types of regions, each
with its own controls. Only one emitter region can be set for a single pEmitter node. If the
pRender is set to 2D, then the emitter region will produce particles along a flat plane in Z
Space. 3D emitter regions possess depth and can produce particles inside a user-defined,
three-dimensional region.
Region Mode Menu
The Region Mode menu includes seven types of regions to define the area, each with
its controls.
All: In 2D, the particles will be created anywhere within the boundaries of the image. In
3D, this region describes a cube 1.0 x 1.0 x 1.0 units in size.
Bézier: Bézier mode uses a user-created polyline to determine the region where
particles are created. The Bézier mode works in both 2D and 3D modes; however, the
Bézier polyline region can only be created in 2D.
To animate the shape of the polyline over time or to connect it to another polyline,
right-click the Shape animation label at the bottom of the inspector and select the
appropriate option from the pop up menu.
Bitmap: A Bitmap source from one of the other nodes in the composition will be used
as the region where particles are born.
Cube: A full 3D Cube is used to determine the region within which particles are
created. The height, width, depth, and XYZ positions can all be determined by the user
and be animated over time.
Line: A simple line control determines where particles are created. The line is
composed of two end-points, which can be connected to Paths or Trackers, as
necessary. This type of emitter region includes X, Y, and Z position controls for the start
and end of the line
Mesh: Any 3D Mesh can be used as a region. In Mesh mode, the region can also be
restricted by the Object ID using the ObjectID slider. See below for a more in-depth
explanation of how mesh regions work.
Rectangle: The Rectangle region type is like the Cube type, except that this region has
no depth in Z space. Unlike other 2D emitter regions, this region can be positioned and
rotated in Z space.
Sphere: This is a spherical 3D emitter region with Size and Center Z controls. Sphere
(3D) is the default region type for a new pEmitter node.
Mesh Regions
Region Type
The Region Type drop-down menu allows you to choose whether the region will include the
inner volume or just the surface. For example, with a pEmitter mesh region, this determines if
the particles emit from the surface or the full volume.
Winding Rule and Winding Ray Direction
The Winding Rule and Winding Ray Direction parameters determine how the mesh region
handles particle creation with meshes that are not closed, as is common in many meshes
imported from external applications. This scenario is common with imported mesh geometry,
and even geometry that appears closed will frequently appear to “leak” thanks to improperly
welded vertices.
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