By default, curves are joined together with a corner type node. This means that the two handles at the node can be moved independently giving complete control over the way the curves meet. This is usually what you want. Sometimes, however, the node is in the middle of a section of the curve you want to keep smooth. This means that you need both handles to move. To change the type of node, click directly on the node with the Edit tool. Choose the new node type in the palette. Here is a brief description and illustration of each type of node.
A corner node’s handles can be moved independently. Each handle can move in any direction and to any length, controlling the segment attached to it. This allows you to create corners of any angle at the node.
A smooth node’s handles form a straight line, touching the curve at the node. Since the handles are a line, moving one handle automatically moves the other, always keeping a smooth curve at the node. The lengths of the handles can vary independently.
Like the smooth node, the handles form a straight line, touching the curve at the node, but the lengths of both handles at a symmetric node are always the same. Moving one handle moves the other, keeping the lengths the same. This means that the curvature is the same on both sides of the node.
A cusped node’s handles are aligned on top of one another. The length of the handles can vary. This forms a sharp point at the node.