Staircasing or aliasing on toon lines

• Turn on Oversample and Oversample post filter in the Paint Effects Rendering Options.
• Normal scene Anti-aliasing Quality in the Render Settings should at least be set to intermediate.
  NoteIf there is aliasing only on the inside edge of toon lines, then it is likely that Occlusion Width Scale was turned off (pfxToon node). Turn it back on. Also make sure Paint Effects Oversample is turned on.

Many of the problems listed below may also appear as anti-aliasing issues. If none of these solutions work, setting profile lines to the Offset Mesh method may work well. Alternatively convert the toon lines to polygons, although for thick lines you may see little cracks at line breaks. As another alternative, render at a higher image file resolution, then resize down to the target resolution with filtering.

Kinks and pops in line width along profile lines

If lines are not smooth enough (that is, there are kinks in them or they pop out in places), try adjusting the following settings in the pfxToonShape node:

• To use the Profile Width Modulation or Curvature Based Width Scaling options, Smooth Profile should be turned on.

  The Profile Width Modulation and Curvature Based Width Scaling options both require smoothly changing lines to work correctly. If they’re on but Smooth Profile is turned off, there will be places where the profile line shows kinks. (These kinks may not always be noticeable because they appear along the view line, which may be fine for the current view.)

• Avoid the Profile Width Modulation and Curvature Based Width Scaling options for hard edges, which behave as if Smooth Profile is turned off.

• Turn on Resample Profile in the Line Resampling section. This will avoid very small segments that can cause sudden direction changes in the stroke.
• In some cases, having a more uniform triangle density can help avoid kinks. Very small or skinny triangles may cause problems.

Profile line does not fit to the exact edge

This typically happens with Smooth Profile when the geometry does not accurately match the surface (or the sense of the surface defined by the vertex normals). A simple example is a cone, which has a pinned normal pointing up at its peak. Therefore when viewed from its vertex normals, a default polygon cone is more like a poorly tessellated smooth hump. As a solution turn on Tighter Profile. If it is still not good enough, then either turn off Smooth Profile (and make Profile Width Modulation zero and turn off Curvature Modulation) or increase the mesh resolution of your geometry in the problem regions.

Wobbly or uneven profile line widths

This could be either of the previous two problems ( Kinks and pops in line width along profile lines and Profile line does not fit to the exact edge). If those solutions don't fix the problem, then consider using Offset Mesh profile lines.

Line ends continue too far, slightly interpenetrating

Turning on Oversample in Paint Effects Rendering Options may help. Try turning off Occlusion Width Scale as well, although this may cause aliasing on the inside edges of lines. Increasing Line Offset to around 0.5 may help the anti-aliasing; however Line Offset can also cause line edges to extend too far. In some cases Offset Mesh profile lines may be a good solution.

Lines appear along joins between surfaces

Border lines work well along open edges, such as the edges of a sheet of paper, but less so in places like fillets and smooth seams. You can usually turn off Border Lines. However if one edge is open and needs a border line while another lies along a seam, you can get rid of just the border on the seam using Remove Flush Borders.

Can't create good crease lines on organic surface, like a human face

The Crease Angle Min/Max are generally insufficient to generate creases along a highly curved organic surface like around nostrils or along the boundaries of lips. You can explicitly define the edges you want the creases to be on as hard, and use Hard Creases Only. However the triangulation of the model will generally not be fine enough to allow good feature lines along triangle boundaries. In these cases it is best to model the feature lines, or paint them on to the geometry with Paint Effects brushes. You can also edit the Pressure Scale ramp on a stroke after painting to get good thick/thin line effects.

Complex Paint Effects brushes assigned to profile toon lines jump around too much when the object moves or the view changes

It is difficult to keep the same profile line start points when rotating an object with respect to the view. However, the effect will be more consistent if Resample Profile is turned on. Additionally setting the Min/Max Segment Length to a fixed value can also help. Profile Width Modulation should be set to zero and Curvature Modulation turned off. Note that if the only effect desired is a wiggly line, then you might be better off mapping the Line Offset attribute instead of using a complex Paint Effects brush. See Tips for creating wiggly toon lines.

Lines don't show up in mental ray or the Maya Hardware renderers

Convert toon to polygons. For profile lines you can also use Offset Mesh profiles, instead of converting toon lines to polygons. Paint effects to NURBS or curves may also be useful.

Tumble in the scene view and transforming toon objects is slow after assigning toon outlines

This is due to the recomputation of the profile lines for the new viewpoint. There are different ways to deal with this issue:

• Turn off Display In Viewport on the toon line node.
• Turn off Show > Strokes in the panel menu (this will also affect Paint Effects strokes and hair as well).
• Use Offset Mesh profile lines - these do not require rebuilding when the view changes.
• Set Paint Effects to Interactive in the Performance Settings window. This will disable building of the toon lines when tumbling the view.
• Assign different toon lines to different objects, rather than one pfxToon node for all objects. This will help when transforming individual objects, as only that object will need to update. (This won't help with tumbling.)
• If an object has many non-profile lines, such as creases, then it might be good to assign one pfxToon node with just profile lines on, and another to the same objects with only the non-profile lines. Thus when the profile node rebuilds there is no additional wait for the non-profile lines to also build.
• Turn off just the profile lines, but turn them back on before rendering.
• In the Stroke Attributes section lower the Display Quality. By default toon lines are drawn as six-sided tubes. At lower display quality this goes down to three-sided tubes, then becomes a simple line at zero quality. Alternately you could turn off Draw As Mesh if the width display of the lines is not important. This will speed up display somewhat, but not dramatically.