The third entry in the Node menu is Node Type. There a several differenttypes of nodes, and their attributes control how the line before and afterthem behaves. When you select a node by right clicking on it, you can changeits properties in the Node Type menu. The first bit of information thatyou can gather from this menu is the type of node you are looking at. Allof its properties are indicated. When the menu comes up, certain attributeswill be grayed out and have a small circle next to them. These are thecurrent attributes of the node you selected. Below are the attributes ofa node on a circle drawn with the shapes tool, and of the center node ofa three point line. let's take a look at how each of these node types behave.
 
 

Circle Node	Point-to-point Node

To see how these different node types behave we are going to begin witha simple shape and change only one node. The shape drawn below was madewith the Point-topoint line tool. This tool is really unique in that youactually create the initial shape in what is essentially a Node edit.
 
 
 

Symmetric

Below you see what happens when the center node is converted to a symmetricnode. The result is no longer a sharp point, but a curve. The arrow allowssome control over the shape of the curve. To widen the curve, grab oneend of the arrow and pull outward.  With a symmetric node, both endsof the arrow behave the same way, lengthening by equal amounts. The angleof the arrow can also be changed by moving the end up or down. Notice thatthe two ends of the arrow always form a straight line and that the curveis always smooth
 
 
 

Asymmetric

An asymetric node also converts are shape to a curve. The real differencebetween a symmetric and asymetric node is the way in which the adjustmentarrow behaves. With the asymetric node, the length of the two ends of thearrow are not linked. You can pull one side of the curve out more thanthe other. The angle of the two halves is still linked however- the arrowremains a straight line when one end or the other is moved up or down.
 
 
 

Cusp

A cusp node is where two curves or lines meet. The center node of ouroriginal point-to-point drawing is already a cusp node. If you want twolines or curves to meet at a sharp angle, a cusp node is what you want.Here I've changed the top point of our shape into a symmetric curve toshow how the arrows behave. The angles of the two halves of the arrow ona cusp node are not linked. You can change them so that you can get a sharpcorner rather than a smooth curve. A cusp node on a curve can be eithersymmetric or asymmetric
 
 
 

Curve Before / Curve After

These options are available if you start out with shapes drawn withstraight lines. They change one of the straight lines on either side ofthe node into a shapeable curve. For reference purposes, "Before" is onthe side of the node closest to the start point of the line or shape, and"After" is the side closest to the Close or End point. When you use thisattribute for a node, either the front part or the rear part of an arrrowwill apear. The initial angle of the arrow will be along the straight line.Changing this angle will change the line to a curve, and pulling the arrowend out will change the shape
 
 
 

Line Before / Line After

The effects of this node type are easier to show if you start with acurve type node already. Below I have converted the central node of ourinitial shape to a symmetric node. Line Before converts the segment beforethe node to a straight line. The curve that follows that straight segmentwill connect smoothly to the segment. Line After does the same thing tothe line segment after the node. Half of a control arrow will remain onthe side of the node that stays as a curve, but the controls are a bitrestricted.  The arrow can be pulled out to change the shape of thecurve, but the angle cannot be changed. The angle is determined by thestraight line. The curvature of the curved section is controlled by howfar out the arrow is pulled. If the end is moved back far enough towardthe node, the curve in effect becomes a straight line. Incidentally, whenyou use the Line Before/Line After types, you also activate the Smooth/Tangentattribute.
 
 
 

The effect of using Line Before or Line After is effected by the propertiesof adjacent nodes. The top point of the circle below was changed to a "Linebefore" node. There is a straight line segment immediately before the node,but notice that it merges smoothly with the node that precedes it. Thisis a Symmetric node with Smooth/Tangent, Curve Before, and Curve Afterproperties.
 
 
 

Smooth/Tangent

This attribute isn't one that you usually set. When you use the LineBefore/Line After types, or the Symmetric or Asymmetric types, the pointbecomes a Smooth/Tangent type into the bargain. Essentially what this meansis that the curves on either side of the node join smoothly, and the controlarrow will be a line that goes through the node point at a tangent.

In some cases you can set this attribute. Below is a shape that wascreated by making the central node a Curve After type and then changingthe angle and length of the control arrow. Notice that there is no smoothcurve at the node point, but a sharp corner. Changing the node type toSmooth/Tangent gives you a smooth curve and a node that is identical toa Line Before type node.