The purpose of this page is merely to provide insight into Adobe Illustrator's capabilities, to inspire thoughts about possible enhancements to other vector editors (just inspire capabilities, not copy functionality verbatim,) and to enhance my ability to explain the illustration workflow in Adobe Illustrator. I wouldn't ask that any other program "copy" Adobe Illustrator, rather I would ask that developers consider the rich context sensitive capabilities of AI's pen tool, which allows artists to create and edit paths as they work in such a way that it is not necessary to select various tools from a toolbox or click icons, and without moving the cursor away from the path.
-kw
Inspired by http://www.angelfire.com/mi/kevincharles/inkscape/aiwf.htm, I added a small improvement to the drawing tools:
- When you switch to the Pen or Pencil tool, they now start in the "add" mode: the selected path displays endnodes to attach to, and any path you draw becomes a single object with the selected path. To start a new path object, deselect the selected path by pressing Esc.
Previously you had to press "a" to go to the add mode, and I'm sure many people were not aware of this. You can still turn the add mode off by pressing "a", but I'm thinking of removing that because I don't see what advantage that may have. If you don't want to continue the path, just deselect it. Removing the "non-add" mode altogether will make the interface simpler. Any comments?
*** Bulia comes to the rescue again! Thanks. --kw
Adobe Illustrator's Pen tool has nine possible states, depending on the context. All of these modes are available while using the Pen tool, in combination with the keyboard (Ctrl, Alt) depending on the context of the cursor location.
The cursor (shown here as a red triangle) changes to the Convert Anchor Point tool when the pen tool is over an anchor point between two other points and the Alt key is pressed.
Just clicking on the anchor point with the Convert Anchor Point tool will convert it to cusp, while clicking and dragging the anchor point with the tool will draw out symmetric control handles. Subsequent edits of the anchor point will be done as if it is a smooth node. Also, the artist can use the Pen tool in the Convert Anchor Point mode to click and drag the control handles of a point, in order to convert it to a corner point so that the control handles can be positioned entirely independently of each other.
The Pen tool appears in this state normally, and its normal behavior is to place a cusp anchor point on the canvas when the mouse is clicked, and when clicked and dragged on the canvas, the tool places an anchor point and draws out symmetric control handles. Subsequent edits of the anchor point will be done as if it is a smooth node.
The Direct Selection tool appears any time the Ctrl key is pressed when the Pen tool is being used. While the cursor appears as the Direct Selection tool a path between two points can be edited by clicking and dragging the path (adjusting the control handles on the points at either end of the segment accordingly) or by clicking and dragging a point to move it, or by clicking and dragging the control handles on the anchor points themselves to adjust the path. Also, clicking off the path with the Direct Selection tool will break the path so that the next point put down on the canvas with the Pen tool will not be a part of the same path. It will start a new path.
When the Pen tool is positioned over the end point on a path, after editing to the path has been done or the path has been broken by clicking on a different object or blank area of the canvas with the Direct Selection tool, the cursor will change to the Continue Path tool. Clicking once on the point will continue the path without an "outgoing" control handle on the point, clicking and dragging from the point will draw out an asymmetrical control handle as if the point were a smooth point.
While continuing a line, placing the Pen tool over the path's first point, the cursor will indicate that clicking on that point will close the path, making a complete shape.
This cursor appears any time you hover over the end point on a continuing path, and simply lets you know that if you click and drag that you'll be pulling out an anchor point. If the point is a cusp type, clicking and dragging with the Convert Point and Continue Path tool will draw out a control handle for the continuing line segment, leaving the previous line segment straight.
If you create a line segment (1) and then create a second line segment (2) and then with the continuing line from (2) position the cursor over a point on line (1) the cursor will change to indicate that clicking on that point will join the two lines into one path. Hovering over a point on a closed path will not enable this feature.
With the Pen tool, positioning the cursor over any point between two others will change the cursor (h) to show the Delete Anchor Point tool, and clicking will remove the anchor point. Positioning the cursor anywhere along the existing path will change the Pen tool to the Add Anchor Point tool, and clicking on the path will create a point at that location.
This combination of capabilities enable artists in Adobe Illustrator to create any kind of line or shape with just the Pen tool and a few keys. This provides enhanced productivity and a more continuous workflow without interruptions for selecting various tools or commands.
Inkscape home page.
Node conversion workflow.
Node conversion refinements.
The way Adobe Illustrator does path plotting and node editing.
