emitter

An emitter is a collection of nodes that control the behavior and look of the emitter and particles. ATTENTION!: omni.particle.system.core is currently undergoing extensive (breaking) changes. Please be aware that systems built with the existing extension will need to be rebuilt in the USD Composer 2023.2 release.

Installation

To use this Node, you must enable omni.particle.system.core in the Extension Manager.

Inputs

Name	Type	Description	Default
active	bool	Is the Emitter node currently active?	True
aim	float[3]	Aim points the particle in a specific direction in x,y,z. If you want to have the particle or shape to be in a specific orientation, disable ‘Face Active Camera’ and ‘Orient with Active Camera’ in the Geometry Replicator or Point Instancer. ‘Aim Inherits Velocity’ in Solver also influences Aim.	[1, 0, 0]
aimRandom	float[3]	Aim the particle in a random direction. If you want to have the particle or shape to be in a specific orientation, disable ‘Face Active Camera’ and ‘Orient With Active Camera’ in the Geometry Replicator or Point Instancer. ‘Aim Inherits Velocity’ in Solver also influences Aim.	[0, 0, 0]
alongAxis	float	‘Along Axis’ uses the Emitter Source to push particles along the X axis. Rotate the Emitter Source to change the push direction. Along Axis averages with ‘Away From Center’. ‘Speed’ influences the particle’s speed.	0.0
awayFromCenter	float	‘Away from Center’ pushes the particles out from the Emitter Source Shape normals. The shape of the Emitter Source influences the direction of the push. Away From Center averages with ‘Along Axis’. ‘Speed’ influences the particle outward push.	1.0
color	float[3]	‘Color’ sets a vertex color per particle spawn. You must have ‘Generate Color and Opacity’ enabled in ‘Options’ and ‘Enable Vertex Colors’ enabled your Material.	[1, 1, 1]
colorRandom	float[3]	‘Random Color’ Sets a random vertex color to the particle. You must have ‘Generate Color and Opacity’ enabled in ‘Options’ and ‘Enable Vertex Colors’ enabled your Material.	[0, 0, 0]
cycleActive	bool	When this is on, emission will be made active and inactive in cycles with period specified by ‘Cycle Duration’, with the active portion specified by ‘Cycle Emission Start’ and ‘Cycle Emission End’.	False
cycleDuration	float	When ‘Activate Cycle Emission’ is on, this is the cycle time period in seconds.	2.0
cycleFadeIn	float	This is a value from 0 to 1 indicating where in the cycle emission starts. This only applies when ‘Activate Cycle Emission’ is on. If this value is 0, the emission will start at the beginning of the cycle, regardless of cycle duration.	0.0
cycleFadeOut	float	This is a value from 0 to 1 indicating where in the cycle emission ends. This only applies when ‘Activate Cycle Emission’ is on. If this value is 1, the emission will stop at the end of the cycle, regardless of cycle duration.	1.0
cycleLoop	bool	When ‘Activate Cycle Emission’ is on and this is off, the cycle runs once, instead of repeatedly.	True
directionRandom	float[3]	Push particles in a random x,y,z Direction.	[0, 0, 0]
emitInsideVolume	bool	When this is on, particles will be emitted throughout the volume of the Emitter Source prims. Otherwise, particles will be emitted from the surface of the Emitter Source prims.	True
emitFromOrientedPointCloud	bool	Emit from oriented point cloud (represented by inputs:positions and inputs:normals attributes).	True
emitFromParticles	bool	Emit from particles (represented by inputs:sourceParticles).	True
generateColorAndOpacity	bool	If enabled the particle will generate color and opacity. This allows the particle to be colored with vertex colors and opacity to be influenced by a float.	False
lifespan	float	Lifespan is how long the particle will live in seconds.	1.0
lifespanRandom	float	Randomly change the range of the lifespan of the particle.	0.0
mass	float	‘Weight’ of the particle.	1.0
objectIndex	int	Object index is valid if you have multiple sources to output. this number corresponds with the order you imported your sources.	0
objectIndexRandom	int	Randomly pick an ‘Object Index’ source in a range.	0
opacity	float	Opacity controls how transparent your particle renders. You must have ‘Generate Color and Opacity’ enabled in ‘Options’ and ‘Enable Opacity’ enabled your Material. If your translucent Particle isn’t displaying correctly, toggle ‘Enable Fractional Cutout Opacity’ in RTX Settings, Ray Tracing.	1.0
opacityRandom	float	Randomly change the particle Opacity per particle spawn. You must have ‘Generate Color and Opacity’ enabled in ‘Options’ and ‘Enable Opacity’ enabled your Material. If your translucent Particle isn’t displaying correctly, toggle ‘Enable Fractional Cutout Opacity’ in RTX Settings, Ray Tracing.	0.0
collisionRadius	float	The radius of the particle collision.	1.0
selfCollisionRadius	float	The radius of the particle self collision.	1.0
radiusInfluencesScale	bool	If toggled the Radius of the collision multiplies the Size of the particle.	True
radiusRandom	float	Randomly set a collision radius in a range.	0.0
randomSeed	uint64	Changing this value changes the particles emitted randomly.	0
rate	float	Constant emission rate, in particles per second, when active.	10.0
ratePerSourceDistance	float	Emission rate, in particles per meter that each emission source moves, when active.	0.0
burstCount	int	Number of particles to emit at time zero or at the beginning of emission in each cycle.	0
rotation	float[3]	Rotate the particle in x,y,z. If you want to have the particle or shape to be in a specific orientation, disable ‘Face Active Camera’ and ‘Orient With Active Camera’ in the Geometry Replicator or Point Instancer. ‘Aim Inherits Velocity’ in Solver also can influence Rotation.	[0, 0, 0]
rotationRandom	float[3]	Randomly rotate the particle in x,y,z along a range. If you want to have the particle or shape to be in a specific orientation, disable ‘Face Active Camera’ and ‘Orient With Active Camera’ in the Geometry Replicator or Point Instancer. ‘Aim Inherits Velocity’ in Solver also can influence Rotation.	[0, 0, 0]
scale	float[3]	Change the size of the particle or shape in x,y,z.	[5, 5, 5]
scaleRandom	float	Randomly change the size of the particle or shape per particle spawn in x,y,z.	0.0
speed	float	The outward velocity of the particle per spawn.	100.0
speedRandom	float	Randomly change the speed of the particle per particle spawn	0.0
addSourceVelocity	float	When this is non-zero, this portion of the velocity of an emission source is added to the particles emitted from it.	0.0
up	float[3]	Change the ‘top’ value of the particle in x,y,z. If you want to have the particle or shape to be in a specific orientation, disable ‘Face Active Camera’ and ‘Orient With Active Camera’ in the Geometry Replicator or Point Instancer. ‘Aim Inherits Velocity’ in Solver also influences Up.	[0, 1, 0]
upRandom	float[3]	Randomly change the ‘top’ value of the particle on spawn. If you want to have the particle or shape to be in a specific orientation, disable ‘Face Active Camera’ and ‘Orient With Active Camera’ in the Geometry Replicator or Point Instancer. ‘Aim Inherits Velocity’ in Solver also influences Up.	[0, 0, 0]
sourceParticlePositionRandom	float	Randomize source particle positions	0.0
inheritSourceParticleVelocity	float	Inherit velocity when emitting from particles	0.0
inheritSourceParticleMass	float	Inherit mass when emitting from particles	0.0
inheritSourceParticleScale	float	Inherit scale when emitting from particles	0.0
inheritSourceParticleRadius	float	Inherit scale when emitting from particles	0.0
inheritSourceParticleColor	float	Inherit color when emitting from particles	0.0
inheritSourceParticleOpacity	float	Inherit opacity when emitting from particles	0.0
inheritSourceParticleObjectIndex	bool	Inherit object index when emitting from particles	False
points	pointf[3][]	Input pointcloud positions	[]
normals	vectorf[3][]	Input pointcloud normals	[]
particles	bundle	Input particle data
sourceParticles	bundle	Input particle data (for emission)
prim	bundle	Input geometry prims
primPath	path	Input geometry prim paths

Outputs

Name	Type	Description	Default
particles	bundle	Emitted particle data