Pen smoothing/stabilization

[ariealerr]

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The current path modeling is very good, but nonetheless, it picks up on my shaky hands and my handwriting gets unreadable. A way to stabilize or smooth the pen strokes as you are writing or drawing would be helpful to create cleaner handwriting.

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That strokes get smoothed as you are drawing, and that there are controls to change how much smoothing is applied.

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Lazy Nezumi Pro, external application, costs money. Haven't been able to get it working. Silky Shark, free alternative. Also have not been able to get it working.

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See opentoonz #81 for examples of pen stabilization and potential ways to implement. This was implemented as cubic Bezier curves in Lorien (lorien #89).

Not related to #531 as I'm looking for stabilization while writing, not after the fact.