Emit From Horizontal Polygons

Creates particles offset from the centers of the horizontal, upward-facing polygons of a mesh.

This compound was designed to generate the cloud that controls the actors' positions in CrowdFX simulations (see Creating the Crowd Particle Simulation), but can be used for other types of particle emissions.

For more information, see Setting Up the Crowd Particle Emission.

Tasks: Crowds/Emitters

Output Ports: Execute

In Geometry Name	Connect the name of the polygon mesh of group from which to emit particles.
Seed	This number is used as the basis for the random variance. If two different particle emitters use the same seed, you may get identical results in their emission. Change the seed value to get a different random pattern.

Positions

Offset from Emitter	The absolute offset from the polygon centers to apply to each particle.
X Variance, Z Variance	The random variance to apply to the particle positions in the X and Z directions.

Initial Values

Note that some of these values are standard particle attributes and are not necessarily useful in CrowdFX simulations, in which the particles are not meant to be rendered but simply to define the positions of the actors.

Size	For non-crowd clouds, this attribute defines how large the particle is. This value is the particle radius, but the particle display size is the diameter. For example, if the Size value (radius) is 1, the diameter (display) size is 2. Some compounds use the Size value to help with collision detection or to define motion, such as Bounce Off Surface or Stick to Surface, for example. See ICE Particle Size for more information. For CrowdFX simulations, this attribute controls the size of the actors as well as the particle that tracks their positions.
Color	Defines the initial particle color as displayed in the viewport. Set the color value using the standard color sliders and color box. Rendered particles do not use the particle color values unless you've set up the shader to do so, such as with an Attribute_Color shader. See ICE Particle Color for more information.
Shape	In general, this attribute defines how the particle shape is drawn on screen. For CrowdFX simulations in particular, this is the shape of the particles that indicate the actors' positions and is not rendered. You have a selection of different methods for displaying particles: point, segment (trails), disc, rectangle, sphere, box, cylinder, capsule, cone, and blob. If you select Blob or Capsule, they are displayed as spheres in the viewport. You must render them to see their true shape. To display trails, select Segment. To render sprites, select the Rectangle shape. If you want particles to collide with an obstacle, they require a shape that has 3D geometry, such as a sphere, box, cylinder, capsule, or cone. See ICE Particle Shapes for more information.
Scale	Sets the particles' Scale attribute, which allows for non-uniform scaling applied on top of Size. In general, this is used for display, rendering, and some collision algorithms. For CrowdFX simulations, this is also used to scale the actors.
State	When using the State nodes to define particle behavior, this value defines which state the particles will be using when created. This value is not used by default in CrowdFX simulations. See Setting the Particle's State ID for more information.

On Creation1

You can plug in nodes that have Execute output ports. These ports only get executed once when a particle gets created.

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