Cineversity

I’m getting unwanted gaps in a Sketch and Toon render.  They appear in lines generated by the Folds parameter.

In this case I’ve created a model of a coffee vending machine.  Because I’ve had problems with artifacts in previous S&T projects (random specks) I did a test render with the camera rotating around the model.  The result is random visible gaps in the line defining the screen left side of the object, visible on frames 27 and 30 of this linked Quicktime.

http://marshall-arts.net/Support/SketchToonGaps.mov

In the past I was able to mitigate specks by adjusting the Total Length modifier in the opacity channel of my S&T material.  Also, limiting the amount of objects that rely on Intersections helped, because that appears to have caused most of the specks or dots.

In this case I’m rendering white lines exhibiting visible black gaps.  I’ve found no way to eliminate the gaps completely.  By breaking the phong shading near those edges I can diminish the appearance of the gaps, but they’re still there.  Both Outline and Folds line types exhibit these gaps.

I’ve attached a simplified project file.  Is there any way to render frames 27 or 30 without those black gaps?  Or do I get to paint in those gaps in After Effects?

Thank you.

Shawn Marshall
Marshall Arts Motion Graphics

Hey Shawn,

If you encounter such problems, and your mesh is just fine (no overlapping, no normal problems etc.), you might try this: Create a copy (set the original to invisible (both red dots on) of your object and triangulate the area of the problem or the whole object.  (Mesh>Commands>Triangulate).

Is that working for you?

All the best

Sassi

That seems to have done the trick!  Thank you so much for the quick reply.

Take care.

Shawn

You’re welcome, Shawn. :o)

Quad based models are certainly preferable, so use it really only on a copy ;o)

If you go to Edit>Project Info>>Attribute Manager>Structure, you see the non planar polygons. See image below. This is not directly a bad thing. But as the render engine (AFAIK) turns all quads during render-time into triangles, one of the two options need to be chosen. Two means if the four points are used 1 and 3 to delver the diagonal or 2 and 4. If that is not really decided, the non planar polygon might be higher or lower, based on how it is triangulated (/ or \). Perhaps that might cause the algorithm to tell the S&T to use the polygon in front or behind it for that—but in some cases those decisions are not in sync, again “As-Far-As-I-Know”. If that happens, the stroke is not produced. Just my idea how that happens. In the moment all quads or at least all non-planar (use the plus button) polygons are defined, before the algorithm starts to work, the problem should be gone. Folds and outlines do not respond to edges as stroke result, so it is a little bit more tricky. I hope that helps.

My best wishes for the project

Sassi