Editing Vectors is done using functions within the Vector Menu, and by using certain tools from the Tools Palette.
Smooth
The Smooth function converts an existing polygon vector (straight lines) to a curved vector.
- Select a Polygon vector object
- Choose Vector > Smooth. The object will be converted to a curved vector object.
Note: The Smooth function will not be available in the menu if you select a curved vector object. The function listed in the Vector menu alternates between Smooth and Polygonise depending on what type of vector object is selected.
Polygonise
The Polygonise function converts an existing curved vector to a polygon vector.
- Select a curved vector object.
- Choose Vector > Polygonize. A sheet will open.
- Enter an Polygonisation Tolerance to convert the object to a polygon (the higher the Tolerance, the greater the number of nodes removed and the simpler the final object).
Switch on ‘Keep Nodes Only’ if you want the vector to be converted to a polygon, while retaining the same number of nodes as in the original.
Optimise
Optimisation changes the number of nodes in vector objects within a certain tolerance, where the tolerance is the maximum distance between the original curve and the new curve at a given number of points.
After creating vector objects on a vector layer, it is possible, at any point, to optimise one or more of them.
- Select the required vector objects.
- Choose Vector > Optimise. A sheet will open.
- Select your required units of measurement and enter a tolerance amount, which will determine the new distance between the nodes and hence the degree of optimisation. Click OK and the objects will be optimised as required.
Note: The higher the Optimisation Tolerance, the greater the number of nodes removed and the simpler the final object. When Optimise is applied to an entirely smooth or polygonal shape its behaviour remains unchanged. However if the shape is compound (a mixture of smooth and polygonal segments) the result will be an entirely smoothed shape.
Open/Close Shape
This function can be very useful if you have drawn a curved vector object without fully completing the shape. The start point and the end point of the same vector will be joined together. When opening a shape, the joining point at the start or end of the shape can be removed.
- Select an open vector object.
- Choose Vector > Close Shape and the shape will be completed.
When closing a shape the software determines whether the closing should be done by adding a smooth arc or a straight line.
Note: When a closed shape is opened the last segment is removed from the shape so you can see the immediate effect of using the Open Shape command. If you want to keep the last segment while opening a shape, use the Vector Selection tool with the Control Key and click on the shape where the opening is intended.
Join
Two separate vector objects can be combined together by joining them.
- Choose the Vector Selection tool and draw around the ends of the two vectors so that the nodes at one end of each object are selected.
- Choose Vector > Join. The two vectors will join together to form one larger vector.
Break/Line Tangents
Tangents are the arms which connect node handles to the nodes on vector objects. They can be broken to allow the separate manipulation of the left and right handles of a node. Separate manipulation of the node handles allows you to quickly design shapes which have sharp edges.
To break tangents:
- Select a node whose tangents are to be broken.
- Choose Vector > Break Tangents.
- Move the node handles individually and you will notice that they can now be moved independently from each other.
Link Tangents is the opposite of Break Tangents. It can be used for retouching a shape altered by removing nodes, or as a complementary tool to work with shapes which have been created using the Join function. Link Tangents does not just link node handles but makes the transition of selected nodes smoother.
To link tangents:
- Select a node whose tangents are to be linked.
- Choose Vector > Link Tangents.
- Move the node handles individually and you will notice that they now work in the standard way.
Note: Nodes that have handles containing three points are required if you want to break or link tangents (the original node position and the two ends of the node handles).