Don't quite understand tweak tool
Inkscape users,
I've recently discovered the the tweak tool, and it's been a real help in shaping objects and pen strokes.
However, it has a side effect I can't quite understand.
If I'm working on one end of an object, the vertices on the other end of the object will get shifted and move around to undesired positions.
It seems like the Tweak tool is trying to preserve the volume of the shape, so if I pull the bottom side down, the top side will also shift down somewhat.
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.
Is there a way I can contain the Tweak tool to localize it's influence more?
I hope my descriptions and questions are clear.
Any advice would be much appreciated.
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).
bulia,
Thank you for responding.
However, it seems that I may have not explained my problem clearly.
Tweak tool does not work by moving vertices (i.e. nodes).
I understand that and my use of the word vertices was perhaps misplaced.
Whether it's nodes, or an approximate polygon, or whatever it is the Tweak tool is moving, it's moving too much of it.
Let me try to be more simple. Let's say I have a large roughly circular shape. I want to use the Tweak tool to alter the bottom. As it is now, when I do so, the top of the shape also shifts around, no matter how small the size of the brush.
How can I make localize the Tweak tool's affect to just the area in an around the size of the brush, and not the entire object or path?
Dave,
As Bulia explained, the tweak tool ends up distorting the path, and in a path with few nodes the closer nodes' curvatures will be affected more readily than one with more nodes. However, no matter the size of the object or the amount of nodes, there will be some distortion to the entire object.
Bulia's solution (to use node sculpting with the node tool) may be more along the lines of what you're looking for, but it operates much differently. You'll have to try it to see if it will work for you.
JF
Dave M G wrote:
bulia,
Thank you for responding.
However, it seems that I may have not explained my problem clearly.
Tweak tool does not work by moving vertices (i.e. nodes).
I understand that and my use of the word vertices was perhaps misplaced.
Whether it's nodes, or an approximate polygon, or whatever it is the Tweak tool is moving, it's moving too much of it.
Let me try to be more simple. Let's say I have a large roughly circular shape. I want to use the Tweak tool to alter the bottom. As it is now, when I do so, the top of the shape also shifts around, no matter how small the size of the brush.
How can I make localize the Tweak tool's affect to just the area in an around the size of the brush, and not the entire object or path?
participants (3)
-
bulia byak -
Dave M G -
Joshua Facemyer