On Tue, Jan 20, 2009 at 11:03 AM, Dave M G <martin@...2100...> wrote:
I looked up information about the Tweak tool on the web, and it seemed that the "Fidelity" setting was the one that controlled the overall influence over the shape. But, despite what I've read, whether I set it to 0 or to 100, I still get this overall distorting of the shape.
Ideally, I want to just move around vertices within the area defined by the size of the brush, or immediately adjacent. I don't want to see influence over the whole object.
Tweak tool does not work by moving vertices (i.e. nodes). It is not aware of them at all. That's its main power and its main weakness. It recasts the path into an approximating polygon with thousands of sides, tweaks its vertices, and then recasts it back into an approximating beziergon. The Fidelity controls the precision of this transformation and thus the number of the nodes in the result, but no Fidelity setting will give you the exact nodes of the original - they will always move somewhat, just like they do after a Simplify.
So, Tweak is not appropriate for node-precise geometric shapes. It strives to preserve the overall shape, but not exact node positions, and it tends to smear sharp corners just like Simplify does. It is more intended for artistic uses in cartoons, sketching, etc. If you want to move a number of nodes without affecting others, just use the Node tool, for example its node sculpting feature (select a number of nodes and Alt+drag one of them).