Houdini 11 Nodes Particle nodes

Emits particles at a location in space.

## Overview

While the Source POP emits particles from existing geometry, the Location POP simply emits particles from a 3D coordinate.

Synonym alert: if you're looking for a way to explicitly set the coordinates of existing particles, you want the Position POP.

## Placing an Emitter in the viewer

To...Do this
Place Emitter anywhere in the scene
1. Click the Emitter tool on the Create Particles tab.

2. Move the cursor into the scene view. You can hold Alt to move off the construction plane.

3. Click to place the particle system anywhere in the scene view and press Enter to confirm your selection.

If you press Enter without clicking, Houdini places the emitter at the origin.

4. Click play to see the particles.

Place Emitter at the origin

Press Ctrl + on the Emitter tool on the shelf.

## Parameters

### Location

System

Coordinate system of the Coordinates parameter below.

 Cartesian Specify location as X, Y, and Z coordinates. Cylindrical Specify location as radius, theta, and Z coordinates (where theta is the angle between the X and Y axes). Polar Specify location as radius, theta and phi coordinates (where phi is the angle between the X and Z axes).
Coordinates

Location in space to emit particles from.

### Birth

This operator has two methods for emitting particles. You can use these methods together or separately:

• Impulse creates a certain number of particles each time the node cooks.

• Constant creates a certain number of particles per second.

 Impulse Activation Turns impulse emission on and off. Impulse emits the number of particles in the Impulse birth rate below each time the operator cooks. A value of 0 means off, any other value means on. Impulse Birth Rate Number of particles to emit each time the node cooks (when Impulse activation is on). Constant Activation Turns constant emission on and off. Impulse emits the number of particles in the Constant birth rate below each second. A value of 0 means off, any other value means on. Constant Birth Rate Number of particles to emit per second (when Constant activation is on). Birth Group Name of a group to put the new points into. Preserve Group If the Birth group already exists, append the new particles to the group instead of replacing its contents. Life Expectancy How long the particle will live (in seconds). Life Variance Particles will live the number of seconds in Life expectancy, plus or minus this number of seconds. Use 0 for no variance.

### Attributes

The parameters on this tab let you control which and how attributes are initialized on the emitted particles. See the POP locals page for explanations of these variables.