05-16-2021, 10:47 AM
I continue about the Simplifying plugin. The last input gives three options to choose from:
First an example of the second choice. I made an elliptic selection and then Selection to path. On the left you see the resulting path with its anchors:
Too many anchors at the belly. I made a new selection covering those anchors (middle picture). Then I called the plugin otherwise with default inputs but choosing "Simplify the part inside the selection, preserve the rest". The result is on the right: the part inside the selection was simplified; in this case it happens to mean that those anchors disappeared altogether.
Also, the result is smoother. Namely, Gimp's Selection to path seems to have difficulties here. At the belly the path had several small straight line segments forming angles. I have even seen a case where there was a tiny concave arc! But the result from the plugin is smooth and nicely arching.
Example 2
Next the last choice, "Preserve the part inside the selection, simplify the rest". This is useful when you want to protect some particular anchors from the process of simplification. Consider the 'QR' on the left:
I first tried to simplify it by setting only "Preserve straight edges" to Yes. The result (not shown here) was good except that even after setting the "Allowed deviation" to a lower value there were clear gaps between the original and simplified paths. Examining those gaps suggested that certain anchors should be preserved. So I made a selection covering those anchors (in the middle picture) and called the plugin again and choosing "Preserve the part inside the selection, simplify the rest" (and of course "Preserve straight edges" set to Yes). The result was much better (on the right). Zooming in (in Gimp, not here!) one sees that the fit is not perfect but anyhow very good. And the number of anchors came down somewhat.
Example 3
The plugin can also be used to remove anchors from paths. Inkscape's node-removing tool is pleasant in that it tries to preserve the shape of the curve by changing the neighbouring handles. Gimp's tool, on the contrary, seems just to delete an anchor without adjusting handles in any way, resulting in distortion in the curve.
The new plugin may be helpful here. Consider the circle on the left.
It is the usual 4-anchor approximation. I made the selection as shown here and called the plugin with "Simplify the part inside the selection, preserve the rest". I also set the "Allowed deviation" a little higher (otherwise nothing happened). I got a 2-anchor approximation of the circle (in the middle). On the right you see the 4-anchor (blue) and the 2-anchor (red) paths on top of each other. Not bad.
- Ignore any selection
- Simplify the part inside the selection, preserve the rest
- Preserve the part inside the selection, simplify the rest
First an example of the second choice. I made an elliptic selection and then Selection to path. On the left you see the resulting path with its anchors:
Too many anchors at the belly. I made a new selection covering those anchors (middle picture). Then I called the plugin otherwise with default inputs but choosing "Simplify the part inside the selection, preserve the rest". The result is on the right: the part inside the selection was simplified; in this case it happens to mean that those anchors disappeared altogether.
Also, the result is smoother. Namely, Gimp's Selection to path seems to have difficulties here. At the belly the path had several small straight line segments forming angles. I have even seen a case where there was a tiny concave arc! But the result from the plugin is smooth and nicely arching.
Example 2
Next the last choice, "Preserve the part inside the selection, simplify the rest". This is useful when you want to protect some particular anchors from the process of simplification. Consider the 'QR' on the left:
I first tried to simplify it by setting only "Preserve straight edges" to Yes. The result (not shown here) was good except that even after setting the "Allowed deviation" to a lower value there were clear gaps between the original and simplified paths. Examining those gaps suggested that certain anchors should be preserved. So I made a selection covering those anchors (in the middle picture) and called the plugin again and choosing "Preserve the part inside the selection, simplify the rest" (and of course "Preserve straight edges" set to Yes). The result was much better (on the right). Zooming in (in Gimp, not here!) one sees that the fit is not perfect but anyhow very good. And the number of anchors came down somewhat.
Example 3
The plugin can also be used to remove anchors from paths. Inkscape's node-removing tool is pleasant in that it tries to preserve the shape of the curve by changing the neighbouring handles. Gimp's tool, on the contrary, seems just to delete an anchor without adjusting handles in any way, resulting in distortion in the curve.
The new plugin may be helpful here. Consider the circle on the left.
It is the usual 4-anchor approximation. I made the selection as shown here and called the plugin with "Simplify the part inside the selection, preserve the rest". I also set the "Allowed deviation" a little higher (otherwise nothing happened). I got a 2-anchor approximation of the circle (in the middle). On the right you see the 4-anchor (blue) and the 2-anchor (red) paths on top of each other. Not bad.