Ink 'n Paint Material

Material Editor > Type button > Material/Map Browser > Ink 'n Paint

The Ink 'n Paint material creates cartoon effects. Rather than the three-dimensional, realistic effect most other materials provide, Ink 'n Paint provides flat shading with “inked” borders.

Snake rendered with ink 'n paint

Because Ink 'n Paint is a material, you can create a scene that combines 3D-shaded objects with flat-shaded cartoon objects.

Rendering that combines realistic shading with cartoon shading

In the Ink 'n Paint material, ink and paint are two separate components, with customizable settings.

Left: The paint component only

Right: The ink component only

Tip: Ink 'n Paint uses the Raytracer Settings, so adjusting raytrace acceleration can have an effect on the speed of Ink 'n Paint. Also, while you work with Ink 'n Paint, disabling antialiasing can speed up the material, until you're ready to create final renderings. (Turning off Ink really speeds it up.)

Note: Motion blur does not work with Ink 'n Paint. (Typically, hand-drawn cartoons are not motion blurred.)

Warning: Ink 'n paint will only give correct results when rendered from a camera or perspective view. It does not work in orthographic views.

Using Ink 'n Paint

You can use Ink 'n Paint on multiple objects, but in general, it tends to work best if you do the following:

  1. Collect the objects for cartoon rendering into a single surface model such as an Editable Mesh.

  2. Assign different material ID values to portions of the model you want to color differently.

    Typically, you would do this at the Element sub-object level, although you can certainly apply different material IDs to faces and polygons as well.

  3. Create a multi/sub-object material. In it, create a sub-material for each of the colors in the model. Make each sub-material an Ink 'n Paint material, then assign colors and maps using each sub-material's Paint controls.

    If necessary, adjust the Ink controls as well.

Tip: ActiveShade works with the Ink 'n Paint material, and can be a good way to preview the material's effect.

Interface

Basic Material Extensions rollout

2-Sided—Makes the material 2-sided. Applies the material to both sides of selected faces.

Face Map—Applies the material to the faces of the geometry. If the material is a mapped material, it requires no mapping coordinates. The map is automatically applied to each facet of the object.

Faceted—Renders each face of a surface as if it were flat.

Fog BG when not painting—When paint is turned off, the painted areas of the material color are the same as the background. This toggle, when on, lets the background in paint areas be affected by fog between the camera and the object. Default=off.

Opaque alpha—When on, the alpha channel is opaque even if ink or paint is turned off. Default=off.

Bump—Adds bump mapping to the material.

  • Toggle—When on, enables the bump map.

  • Spinner—Controls the bump map amount.

  • Map button—Click to assign a map to use for bump mapping.

Displacement—Adds displacement mapping to the material.

  • Toggle—When on, enables the displacement map.

  • Spinner—Controls the displacement map amount.

  • Map button—Click to assign a map to use for displacement mapping.

Paint Controls rollout

Paint is the main color of the material.

There are three main components of the “paint” of Ink 'n Paint. Each has several associated controls, most of which are documented toward the end of this section.

Lighted—The fill color for the lighted side of objects. Default=light blue.

Turning off this component makes the object invisible, except for the ink. Default=on.

Left: A lighted character

Right: Lighted and Highlight both turned off to render only the ink

  • Paint Levels—The number of shades of color that are rendered, from light to dark. Lower values make objects look flatter. Range=1 to 255. Default=2.

    Increasing the value of Levels increases the number of shades of the basic color seen in the lighted area.

Shaded—The value in the spinner at the left is the percent of the Lighted color that appears on the unlighted side of objects. Default=70.0.

Turning off this component displays a color swatch, which you can use to assign a distinct color to shaded areas. Default=on.

Increasing the value of Shaded increases the saturation of the shaded area. You can also use Shaded to assign a distinct color for shading.

Highlight—The color of the specular highlight. Default=white.

When this component is turned off, there is no specular highlight. Default=off.

Tip: A specular highlight can destroy the illusion of 2D. Use this component sparingly.

Left: No highlights

Right: Highlights turned on

  • Glossiness—The size of the specular highlight. The greater the Glossiness, the smaller the highlight. Default=50.0.

    Increasing glossiness decreases the size of the highlight.

Color component controls:

These are the controls that are duplicated for each of the paint components. Each has an on/off toggle, a main control, and then on the right, a set of map controls.

  • Check box—The check box at the left of the rollout enables or disables that particular component. In the case of Shaded, it toggles between a percentage value (of the Lighted color) or a distinct Shaded color.

  • Color swatch or spinner—The main control for each component. Click a color swatch to display a Color Selector and set the color of the component. In the case of Shaded, this control can also be a percentage spinner.

  • Map spinner—The spinner to the right of the main control is the percentage of the map to use. Default=100.0.

    Mapping the Lighted component

    Right rear: The original, unmapped material

    Left: Lighted component with a falloff map applied

    Right front: Lighted component with a bitmap applied

  • Map check box—The check box between the spinner and the button enables or disables the map. Default=off until a map is assigned, then on.

  • Map button—Click the button to assign a map to this component.

    While a map is assigned and enabled, at 100 percent it completely overrides the main color component. At lower percentages, the map is blended with the color.

Ink Controls rollout

Ink is the linework, the outlines, in the material.

Except for Ink Width, each of the ink components has an on/off toggle and a color swatch. Click the color swatch to display a Color Selector and change the ink component's color. Each ink component, Ink Width included, also has a set of map controls.

Ink—When on, the rendering is “inked.” When off, no ink lines appear. Default=on.

Left: Rendering with ink

Right: Ink turned off

Ink Quality—Affects the shape of the brush and the number of samples it uses. When Quality equals 1, the brush is a “+” shape, and samples are taken over an area of 5 pixels. When Quality equals 2, the brush is octagonal and the samples are taken over an area of 9 to 15 pixels. When Quality equals 3, the brush is nearly circular, and samples are taken over an area of 30 pixels. Range=1 to 3. Default=1.

Tip: For most models, increasing the Quality value introduces only a very subtle change, and can take considerably longer to render. Do so only when a sub-object's ink shows too many artifacts in the finished rendering, using the default Ink Quality. (Don't rely on the ActiveShade preview, which will tend to be aliased.)

Ink Width—The width of the ink, in pixels. This is specified by the spinner labeled Min (minimum) unless Variable Width is turned on. When Variable Width is on, the Max (maximum) spinner is also enabled, and the ink width can vary between the minimum and maximum values. Default: Min=2.0, Max=4.0.

Left: One-pixel ink width

Middle: Five-pixel ink width

Right: Ink width varies from one to five pixels.

Variable Width—When on, the ink's width can vary between the minimum and maximum Ink Width values. Ink with Variable Width looks a bit more streamlined than ink with a constant width. Default=off.

The thickness of ink can be mapped.

Left: Thickness mapped with a gradient map

Right: Thickness mapped with a noise map

Clamp—When Variable Width is on, sometimes the scene lighting causes some ink lines to become so thin they nearly disappear. If this happens, turn on Clamp, which forces the ink width to always remain between the Min and Max values, regardless of the lighting. Default=off.

Outline—The ink where the outer edges of the object appear against the background or in front of a different object. Default=on.

Left: Rendering the outline only

Right: Rendering only the overlap and underlap

  • Intersection Bias—Use this to adjust artifacts that might appear when two objects intersect each other. In effect, this moves the inked object closer to the rendering point of view, or farther away, so Ink 'n Paint can decide which object is in front. Positive values push the object away from the point of view, negative values pull it closer. Default=0.0.

Overlap—The ink used when a portion of an object overlaps itself. Default=on.

  • Overlap Bias—Use this to adjust artifacts that might appear in ink that traces the overlap. It says how far the overlap has to be in front of the rear surface for Overlap ink to turn on. Positive values push the object away from the point of view, negative values pull it closer. Default=10.0.

Underlap—Similar to Overlap, but applies ink to the farther surface rather than the nearer one. Default=off.

  • Underlap Bias—Use this to adjust artifacts that might appear in ink that traces the underlap. It says how far the underlap has to be behind the front surface for Underlap ink to turn on. Positive values push the object away from the point of view, negative values pull it closer. Default=0.0.

SmGroup—The ink drawn between the boundaries of smoothing groups. In other words, it inks the edges of the object that have not been smoothed. Default=on.

Mat ID—The ink drawn between different material ID values. Default=on.

Tip: If two Ink 'n Paint materials overlap in the viewport, and both have Mat ID turned on, you will often get a doubly thick ink line where they overlap. To correct this, turn off the Mat ID component for one of these materials.

Inking the edges between sub-materials

  • Only Adjacent Faces—When on, inks the material ID edge between adjacent faces, but not between one object and another. When off, inks the material ID edge between two objects or other non-adjacent faces. Default=on.

  • Intersection Bias—When Only Adjacent Faces is turned off, use this to adjust any artifacts that appear at the boundary between two objects with different material IDs. Default=0.0.

Map controls—There are map controls for each of the ink components: Width, Outline, Overlap, Underlap, SmGroup, and Mat ID. These work the same as they do for the material's paint components, as described above.

Mapping the outline and overlap components to simulate the look of drawing on paper

Troubleshooting

Here are some commonly encountered problems, and potential solutions:

  • Internal ink lines are missing.

    The Overlap bias is probably too high. Decrease it. If Underlap is turned on, this might also have too high a bias.

    Another possible reason is that you have a self-intersecting object, or an object built by attaching smaller objects, thus creating intersecting faces. In this case, set up the objects to use the Mat ID or SmGroup ink components. If elements already have differing material IDs, try turning off Only Adjacent Faces.

  • Ink looks sloppy on sloping parts of the object.

    The Overlap or Underlap bias might be too low. Try increasing it.

  • Ink looks sloppy between interpenetrating objects.

    Find out which ink component is the sloppy one. Then adjust its bias control.

  • Ink lines disappear or are too narrow when Variable Width is on.

    Turn on Clamp. You can also try to see if reducing the lighting level helps. Or, you can try turning off Variable Width, then assigning a Falloff map to the Ink Width component.

Tip: To isolate which ink component is causing a problem, you can try assigning each component a different, distinctive (and easy to read) color, then rendering the image.

Warning: Ink 'n paint will only give correct results when rendered from a camera or perspective view. It does not work in orthographic views.


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