Emitters

ObiEmitters have a lot of parameters that allow you to specify how and when to emit particles:

Emitter material

A reference to an ObiEmitterMaterial asset. This determines internal physical properties of the fluid being emitted. See emitter materials for more info.

Num particles

Maximum amount of emitted particles. The emitter will generate a particle pool containing this amount of particles, newly spawned particles will be taken out of the pool and destroyed particles will return to it for later reuse.

World velocity scale

In case of simulating in solver local space, how much of the world velocity is transferred to the particles.

Material

Material used to resolve collisions. See collisions for more info.

Speed

Emission speed. When set to zero, the emission will completely cease. Higher values will cause the emitter to continuously emit fluid at this speed (in meters per second). The amount of particles emitted per second is automatically calculated depending on the fluid resolution and emitter shape size.

Lifespan

Amount of seconds elapsed between the birth of a particle and its return to the emitter's particle pool.

Random velocity

Amount of random direction applied to the initial velocity of all particles. A setting of 0 will cause particles to be emitted in the direction specified by their current spawn point, while a setting of 1 will cause them to be emitted in a completely random direction.

Emitter shapes

You can add a emitter shape to any object in the scene. Once you assign an emitter component to the shape, the emitter will begin using it to emit particles. There are a few standard emitter shapes, though you can create custom ones trough scripting if needed:

Disk

Disk emitters generate particles using a circle defined in their XY plane. Parameters:
Color: overall color tint of particles emitted trough this shape.
Radius: radius of the circle in local units.
Edge emission: if enabled, particles will be emitted from the circle's edges, instead of its interior.

Edge

Edge emitters generate particles from a line segment defined along their X axis. Parameters:
Color: overall color tint of particles emitted trough this shape.
Lenght: lenght of the edge in local units.
Radial velocity: amount of velocity twisting along the lenght of the edge.

Sphere

Sphere emitters generate particles from a spherical volume. Parameters:
Color: overall color tint of particles emitted trough this shape.
Sampling method: Lets you switch between grid-based sampling of the sphere's volume, or regular sampling of its surface.
Radius: radius of the sphere in local units.
Density: controls the amount of sampling points used.