How to fill an ellipse with a Turbulence pattern in inkscape?

Question

How do I add the Turbulence filter to an ellipse in inkscape? I create an ellipse shape.

I select the ellipse and go to the Filter Editor. I create a new filter and add the turbulence filter and enable the filter. Instead of giving me an ellipse with turbulence I just see a rectangle with turbulence.

By contrast if I use a Gaussian Blur it appears to give my ellipse a blur as desired.

Why does this happen and how can I fill an ellipse with the turbulence pattern?

Answer 1

Two possible ways are the following (there may be others):

1. By using clipping

• draw your ellipse
• duplicate it (Ctrl+D)
• move your duplicate to another layer (optional, for convenience only), which you hide for the moment
• apply turbulence filter to original ellipse
• unhide the duplicate ellipse, select the original ellipse (now with turbulence filter applied and looking like a rectangle) and the duplicate ellipse together, and do Object > Clip > Set.

(General information on clipping in Inkscape.)

2. By adding a "composite" effect to the filter

• in Filter editor, first add turbulence effect (as mentioned in the question)
• then add a "composite" effect. The composite effect has two entries: one should be the output of the turbulence effect, the other should be the source graphic. In "Effect parameters", set "operator" to "In" (see screenshot below).