Game Development Reference
Figure 13-6 . The Shape Tracer creates shapes automatically
Click the magic wand icon in the toolbar called the Shape Tracer to open the Shape
Tracer dialog shown in Figure 13-6 .
The Shape Tracer shows the shape's image and an overlay of the shape it's going to
create when you click the OK button. Below the image are a slider and buttons to its
left and right that control the zoom level of the image. The image zoom settings don't
affect how the shape is created.
The most important setting you'll want to adjust in the Shape Tracer is the Tolerance
setting. Tolerance changes how accurately the image is traced to create a shape, which
directly influences the number of vertices used for the shape, and the number of ver-
tices of a shape in turn influence the performance of the physics simulation. Generally,
you should always strive to achieve adequate collision responses with the least amount
of vertices. The more important accurate collisions are for your game, the more ver-
tices you should allow for some objects. At the same time, if you add many objects us-
ing the same shape, using a shape with fewer vertices will result in better performance.