Setup Rollout (Particle Paint)
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Select a Particle Paint helper. Modify panel Setup rollout

The parameters on the Setup rollout determine the density and placement of particle seeds as well as stroke timing.

ImportantFor these parameters to affect the strokes or seeds, you must set them before you create particle seeds. Changing values after creating particle seeds has no effect on the existing strokes or seeds.


Freehand Paint

Activates a freehand paint tool, allowing you to drag anywhere in an orthographic viewport to set particle seeds. The timing of the drag across an object determines the base timing for particle birth when used with the Birth Paint or Particle Paint operators. This option is available only on the Modify panel.

ImportantTo use the freehand paint tool, you must work from one of the orthographic viewports such as Top or Front. You cannot use this tool in Perspective, Camera, or Spotlight viewports.

Each time you release the mouse while using this tool, you create an individual stroke. You can create as many strokes as you like for each Particle Paint helper. Particle timing and other options for each stroke are governed by the other settings on the Setup rollout.

To stop creating strokes, right-click in the active viewport or click the Freehand Paint button again.

Pick Stroke Spline

Allows you to pick one or more standard splines as paths for the particle seeds. Particles are then placed along this spline, but are projected on to 3D surfaces into the orthogonal viewport. The splines do not have to be in front of the surfaces in the orthographic viewport; Particle Paint will project from splines to surfaces as if the splines were in front of the objects regardless of their actual positions in 3D space.

The picked splines can be either open or closed splines. NURBS curves cannot be used as spray splines.

You can pick as many splines as you like, and each spline picked is considered to be a separate stroke. The stroke starts from the spline's first vertex, and continues along the spline until it reaches the end of the spline (or the first vertex, in the case of closed splines).

Total Particle Seeds

The total number of particle seeds that have been generated.


The number of strokes created by the Particle Paint helper.

Brush Radius

Adjusts the spray emitter's nozzle size. The change in size is reflected in the Particle Paint icon. This value determines the distance around the center of the nozzle by which particle seeds spread when using either method to generate particle seeds. This value can be animated over time.

Paint Density group

These controls set the particle seeds' area of distribution within the emitter nozzle.

Center (%)

Percentage of particle seeds that spray at the center of the nozzle.

Sides (%)

Percentage of particle seeds that spray at the edges of the nozzle. Higher percentages result in wider bands of particles.

Paint Flow Rate group

These controls determine how many particle seeds are emitted and how fast they are emitted over the course of a single stroke. For the freehand paint method, a stroke is defined by the time you press the mouse button to start the stroke, until you release the mouse button. For a spline, one stroke is distributed over each spline picked.

Stroke Limit

Sets the overall number of particle seeds that can be emitted per stroke when using the freehand or spline methods. So if Seeds p/sec is 25.0 and Stroke Limit is 100.0, you can spray for four seconds before running out of particle seeds with that one stroke. This parameter is overridden by the Stroke spray rate type, selected under Type (see following).


Sets the spray rate type. The available choices are Time, Length, and Stroke. Each one works with one of the later parameters to set the spray rate.

  • TimeSets the spray rate by particle seeds per second.
  • LengthSets the spray rate by spatial movement of the nozzle.
  • StrokeSets the spray rate with a specific number of particle seeds per stroke, regardless of stroke length. This option overrides the Stroke Limit parameter (see preceding).
[rate value]

Depending on the Type setting (see preceding), one of these is available to set the number of seeds created when painting.

  • Seeds p/secThe number of particle seeds emitted per second as you draw in viewports. Higher values cause more seeds to be emitted. This option is available only for the Time spray rate type (see preceding).
  • Paint StepThe distance the nozzle center must move between emitting individual particle seeds. Higher values cause fewer seeds to be emitted during a stroke. This option is available only for the Length spray rate type.
  • Total AmountDetermines the total number of particle seeds per stroke, regardless of the stroke length in units or time. Seeds are evenly distributed over the stroke time. This option is available only for the Stroke spray rate type.

Brush Adjustment group

These controls are used for fine-tuning the Brush Radius and Flow Rate with regard to stroke timing.


Provides for varying the seed-painting radius over the course of each stroke. Alternatively, you can animate the Brush Radius parameter to vary the brush size, but that animation occurs in absolute time (that is, within a specific frame range). Use this option to adjust the brush radius within a single stroke regardless of its start and end times.

Clicking Radius opens the Brush Radius Graph (Particle Paint). The settings on the graph are in effect when the Radius option is on.


Provides for varying the seed-painting rate over the course of each stroke. Alternatively, you can animate the Seeds p/sec parameter to vary the rate, but this animates the rate in absolute time (that is, within a specific frame range). Use the Rate option to adjust the seed painting rate within a single stroke regardless of its start and end times.

Clicking Rate displays the Paint Flow Rate Graph (Particle Paint). The settings on the graph are in effect when the Rate option is on.


Display Type

This drop-down list gives you the choice of how to display the particles in the viewports. You can choose Ticks or Flags as the display type. The Flags type gives more information about each seed’s rotational data. The pole of a flag marker is aligned with its seed’s local Z axis, while the banner points in the direction of the local X axis.

Particle Size

Sets the size of the flag markers. Available for the Flags type only.

Stroke Start group

The settings in this group determine the start frame for particle seeds generated by a stroke. These timing values can be used later by the Birth Paint and Placement Paint operators for precise timing of every particle emitted.

Stroke Start

Choose either of the following:

  • Current FrameStarts the stroke timing at the current frame.
  • FixedStarts the stroke timing at the indicated frame.

Stroke Stop group

These settings specify the method for determining the duration or stop frame of the stroke.

Stroke Stop

Choose one of the following:

  • Real-Time OffsetDefines stroke time by the actual time taken for drawing the stroke. If you created a stroke by picking a spline, then the default time for the stroke is one second.

    Use the Time Scale % parameter to define the correspondence between the animation time (frames of animation) and the real-world time when a stroke is drawn. For example, a value of 100.0 means that one second of actual time corresponds to 30 frames of animation (for NTSC), while a value of 50.0 means that one second of stroke drawing corresponds to 15 frames of animation.

    NoteAdjusting the Time Scale % value changes the effective flow rate of the painting, since the Seeds p/sec parameter uses animation time, not drawing time.
  • FixedStops the stroke at the specified frame, in absolute time.
  • DurationSets the stroke length in frames.
Auto Adjust Current Frame

Aligns the start of each successive stroke automatically with the stop time of the previous one. If you turn on this option for an exsisting stroke, the time slider is adjusted to the stop moment of the stroke. This option is available only if Stroke Start is set to Current Frame and Stroke Stop is set to either Real-Time Offset or Duration.

Auto Adjust Global Timing

Adjusts emission timing of the related Birth Paint operator automatically.

The Birth Paint operator has its own parameters that define when particles start and stop emission. When this switch is off, Particle Flow fits the timing of the strokes into the Birth Paint operator’s Start/Stop interval. However, when this option is on, Particle Paint allows the related Birth Paint operator to adjust its emission timing to the timing of the strokes.

Icon Size

Adjusts the overall size of the helper icon, but does not affect the nozzle radius.

Paint Spread Uniqueness group

These settings randomize particle-seed distribution over a stroke. If you pick the same spline for a stroke, the helper generates the same placement for seeds. To generate varied particle placement for the same spline, change the Seed value.


Specifies a randomization value. Not otherwise related to particle seeds.


Generates a new Seed value.