Particle Paint Helper

The Particle Paint helper enables you to apply particle seeds with a specific pattern and timing onto the surface of one or more objects.

Particle seeds painted with the Particle Paint helper are not particles, but are seeds that can be turned into particles with the Birth Paint or Placement Paint operators in Particle Flow.

You can spray particle seeds with a freehand painting tool, or by using 3ds Max splines to define the pattern. Particle Paint works in any orthographic viewport such as a Front or Top view. It sprays directly into the viewport (that is, perpendicular to the plane of view), and plants particle seeds on the surface of first object that it hits.

Particle Paint Icon

To create the Particle Paint icon, click Create panel Helpers Particle Flow Particle Paint, and then drag in a viewport.

The Particle Paint icon is composed of two parts: a circle and a spray can icon.

Particle Paint helper icon

The Particle Paint helper uses the metaphor of a real-world airbrush to spray-paint particle seeds onto a surface. When you use the Freehand paint tool, particle seeds are sprayed through a virtual nozzle, as with an airbrush. The circle in the Particle Paint icon represents the size of the nozzle. If, on the other hand, you use stroke splines, the particle seeds are sprayed along the spline.

The Particle Paint icon does not have to sit in front of or on the objects on which you plan to paint particle seeds, nor does it have to be created in the viewport in which you plan to paint.

Deleting the Particle Paint icon deletes all particle seeds and strokes associated with it.

Strokes

The Particle Paint helper works with particle groupings called strokes. With a real-world airbrush, each time you depress the nozzle, spray, then release the nozzle, you create a stroke. With the freehand tool, you can drag across objects several times to create strokes. With the spline method, you can pick several splines to create different strokes.

Each set of strokes stored with the Particle Paint helper can be used as a series of birth instructions with the Birth Paint and Placement Paint operators in Particle Flow. You can work with each stroke separately to adjust its timing, delete some of its particles, and perform other operations. To edit particle seeds and strokes after creating them, select the Particle Paint helper and then access the Editing rollout on the Modify panel.

You can undo the creation of strokes, and you can also delete particle seeds or change particle seed timing with the options on the Editing rollout. You can also restart by deleting the Particle Paint helper and creating a new one.

Procedures

Example: To create strokes with freehand painting:

  1. Create a sphere in the Top viewport.
  2. Click Create panel (Helpers). Choose Particle Flow, then on the Object Type rollout, click Particle Paint. Drag in any viewport to create the Particle Paint helper.
  3. With the Particle Paint helper selected, go to the Modify panel.
  4. On the Setup rollout, click Freehand Paint.
  5. In the Front viewport, position the mouse cursor over the sphere. A set of nozzle crosshairs appear, indicating that Particle Paint is ready to paint.
    Note: You can create freehand strokes only in orthographic viewports.
  6. Drag the nozzle crosshairs over the sphere for a few seconds, then release.

    After you release, the particle seeds appear as +-shaped tick marks on the object surface.

    You have just created one stroke.

  7. Move the time slider to a later frame.
  8. Drag the nozzle over a different part of the sphere to create another stroke.
  9. Click the Freehand Paint button to turn it off.
  10. On the Editing rollout, turn on Show Particle Timing.
  11. Drag the time slider to see the particle timing.

    As you drag the time slider, the particle seeds change color as they become eligible for birth. You will see the second stroke begin at the frame to which you moved the time slider before making the stroke.

To create strokes with splines:

  1. Create a 3D object in any viewport.
  2. In the Front viewport, create two splines, such as a line and a circle. Place the splines so they overlap the 3D object when viewed in the Front viewport.

    The splines don't have to actually be in front of the 3D object in 3D space. But because Particle Paint will project the splines onto the object to create particle seeds, the splines must overlap the 3D object when viewed in the viewport.

  3. Click Create panel Helpers . Choose Particle Flow, then on the Object Type rollout, click Particle Paint. Create the Particle Paint helper in any viewport.
  4. With the Particle Paint helper selected, go to the Modify panel.
  5. On the Setup rollout, click Pick Stroke Spline.
  6. Activate the Front viewport.
  7. With the time slider at frame 0, click one of the splines in the Front viewport.

    This creates the first stroke.

  8. Move the time slider to a later frame, and click another spline.

    This creates a second stroke, starting at the current frame.

  9. Click Pick Stroke Spline again to turn it off.
  10. On the Editing rollout, turn on Show Particle Timing.
  11. Drag the time slider to see the particle timing.

    As you drag the time slider, the particle seeds change color as they become eligible for birth. You will see the second stroke begin at the frame to which you moved the time slider before picking the second spline.

Interface

The controls on the Setup, Orientation, and Mapping rollouts set parameters for particle seeds upon creation. These settings go into effect when you create the particle seeds with the freehand or spline tool. Changing the parameter values after you create particle seeds has no effect on the seeds. After particle seed creation, you can change some aspects of seeds and strokes with the Editing rollout settings.

The Particle Paint rollouts are as follows:

Setup Rollout (Particle Paint)

Layout Rollout (Particle Paint)

Orientation Rollout (Particle Paint)

Mapping Rollout (Particle Paint)

Editing Rollout (Particle Paint)