Birth Paint Operator

The Birth Paint operator uses a Particle Paint helper as a reference for creating particles. With the Particle Paint helper, you place particle seeds on an object with a specific pattern and timing. The Birth Paint operator creates particles from these seeds, initializing particle position, rotation, mapping and selection status.

• Particle View > Click Birth Paint in an event or add a Birth Paint operator to the particle system and then click it.

Tip: If the Particle Paint helper does not generate a sufficient number of particles, but you want to use the overall particle birth pattern and rate set by the Particle Paint helper, use the Spawn test after Birth Paint in the event to spawn additional particles at each particle seed's location.

Interface

Particle Paint Helper group

[button]

Choose a Particle Paint helper as the source for particle seeds by clicking the button, labeled “None” by default, and then selecting a helper. After doing so, the helper name appears as the button label.

Total Particles

Shows the total number of particles in the Particle Paint helper. The amount of particles actually generated depends on the Quantity Multiplier of the master PF Source object. If the multiplier value is less than 100%, the Birth Paint operator samples the particles from the helper. If the multiplier is greater than 100%, some particle seeds from the helper generate multiple particles.

Total Strokes

The total number of strokes in the Particle Paint helper.

Emit Start

The frame number at which particles start to emit, beginning with particle seeds at the start of the first stroke.

Emit Stop/Duration

Choose either of two methods of setting the length of time particles are emitted:

• Emit Stop Sets the frame number at which particles stop emitting. The time to emit all strokes in the Particle Paint helper is scaled to fit the time between Emit Start and Emit Stop.
• Duration Sets the duration of the emission in frames. If the Duration value is not the same as the stroke time, particle emission timing is scaled to fit the Duration value.

Reset To Stroke Time

Adjusts the Emit Start, Emit Stop, and Duration values to the timing of the Particle Paint helper's strokes. The Emit Start value is set to the earliest start time of the strokes, and the Emit Stop time is set to the latest stop time of the strokes.

Subframe Sampling

When on, particles are emitted on the sub-frame timing as defined by the strokes timing and the Emit Start and Emit Stop values. This can help avoid particle clumps. When off, the particle creation time is clamped to the nearest whole frame value.

Lock At Painted Objects group

This group of controls tells the Birth Paint operator how to continue controlling particle position/rotation after particles are born. These options apply only if objects painted with the Particle Paint helper are animated, and the Objects option on the Particle Paint helper's Layout rollout is on.

Position

Causes all particle pivot points to stick firmly to the painted objects.

Rotation

Causes all particles to retain their original orientations. Even if the painted object has surface animation, particles retain the same normal orientation they had at the moment of generation.

Acquire Selection

Uses the Particle Paint helper selection. This selection overwrites the PF Source particle selection, if any. Choose the sub-object selection Particles or Strokes (see Editing Rollout (Particle Paint)).