Changing node from Sharp to Smooth unnecessarily changes curve

[Corgi]

I'm using Designer 2.2.1

Normally when changing a node from Sharp to Smooth (or Smart) you'd expect the curve to change. But if the curve at the Sharp node is actually "smooth" to begin with, there's no reason for the shape of the curve to change.

It may not be possible to create this scenario from scratch within Designer, since when you have a Sharp node and move a control point such that it becomes parallel to the other control point, the node automatically becomes Smooth. However, this is not the case when opening an SVG file or editing an embedded SVG file. Consider this portion of a Designer file that was used to open an SVG file:

The node in the center is Sharp, yet the control points are aligned (perhaps give or take a rounding error). But if I change the node type to Smooth, this is what I get:

This behavior makes touching up imported graphics imprecise and much more tedious. Designer should recognize this situation and leave the curve as-is when converting the node to Smooth.

Of course, this situation would arise much less frequently if Designer had its own bitmap trace support. 😉

The attached afdesign file was derived from opening an SVG file with Designer (I created the SVG file by tracing it with CorelDraw and exporting). You can play around with it if you want.

 

sharp-to-smooth.afdesign

[debraspicher]

I've run into this as well when editing imported vectors. I feel like this has happened too when I've merged paths in Affinity itself and I've had to change my strategy when working with points to avoid unwanted changes to the initial curve.

[Bit Arts]

I see this a lot in Affinity Designer with hand traced curves - and I see it less in other programs. Almost got used to it, expect it and I correct it almost subconsciously.

But it's an algorithm weakness that should definitely be significantly improved in Affinity. 

[Lee_T]

Hi Corgi,

I've logged this for the devs to take a look at.

Lee