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 |
|
Is the Emitter node currently active? |
True |
aim |
|
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 |
|
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 |
|
‘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 |
|
‘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 |
|
‘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 |
|
‘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 |
|
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 |
|
When ‘Activate Cycle Emission’ is on, this is the cycle time period in seconds. |
2.0 |
cycleFadeIn |
|
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 |
|
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 |
|
When ‘Activate Cycle Emission’ is on and this is off, the cycle runs once, instead of repeatedly. |
True |
directionRandom |
|
Push particles in a random x,y,z Direction. |
[0, 0, 0] |
emitInsideVolume |
|
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 |
|
Emit from oriented point cloud (represented by inputs:positions and inputs:normals attributes). |
True |
emitFromParticles |
|
Emit from particles (represented by inputs:sourceParticles). |
True |
generateColorAndOpacity |
|
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 |
|
Lifespan is how long the particle will live in seconds. |
1.0 |
lifespanRandom |
|
Randomly change the range of the lifespan of the particle. |
0.0 |
mass |
|
‘Weight’ of the particle. |
1.0 |
objectIndex |
|
Object index is valid if you have multiple sources to output. this number corresponds with the order you imported your sources. |
0 |
objectIndexRandom |
|
Randomly pick an ‘Object Index’ source in a range. |
0 |
opacity |
|
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 |
|
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 |
|
The radius of the particle collision. |
1.0 |
selfCollisionRadius |
|
The radius of the particle self collision. |
1.0 |
radiusInfluencesScale |
|
If toggled the Radius of the collision multiplies the Size of the particle. |
True |
radiusRandom |
|
Randomly set a collision radius in a range. |
0.0 |
randomSeed |
|
Changing this value changes the particles emitted randomly. |
0 |
rate |
|
Constant emission rate, in particles per second, when active. |
10.0 |
ratePerSourceDistance |
|
Emission rate, in particles per meter that each emission source moves, when active. |
0.0 |
burstCount |
|
Number of particles to emit at time zero or at the beginning of emission in each cycle. |
0 |
rotation |
|
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 |
|
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 |
|
Change the size of the particle or shape in x,y,z. |
[5, 5, 5] |
scaleRandom |
|
Randomly change the size of the particle or shape per particle spawn in x,y,z. |
0.0 |
speed |
|
The outward velocity of the particle per spawn. |
100.0 |
speedRandom |
|
Randomly change the speed of the particle per particle spawn |
0.0 |
addSourceVelocity |
|
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 |
|
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 |
|
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 |
|
Randomize source particle positions |
0.0 |
inheritSourceParticleVelocity |
|
Inherit velocity when emitting from particles |
0.0 |
inheritSourceParticleMass |
|
Inherit mass when emitting from particles |
0.0 |
inheritSourceParticleScale |
|
Inherit scale when emitting from particles |
0.0 |
inheritSourceParticleRadius |
|
Inherit scale when emitting from particles |
0.0 |
inheritSourceParticleColor |
|
Inherit color when emitting from particles |
0.0 |
inheritSourceParticleOpacity |
|
Inherit opacity when emitting from particles |
0.0 |
inheritSourceParticleObjectIndex |
|
Inherit object index when emitting from particles |
False |
points |
|
Input pointcloud positions |
[] |
normals |
|
Input pointcloud normals |
[] |
particles |
|
Input particle data |
|
sourceParticles |
|
Input particle data (for emission) |
|
prim |
|
Input geometry prims |
|
primPath |
|
Input geometry prim paths |
Outputs
Name |
Type |
Description |
Default |
---|---|---|---|
particles |
|
Emitted particle data |