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To avoid problems when using patterns, the developer should keep these hints in mind:
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Patterns involve transformations that may include rotation and scaling, both of which require the specification of a fixed point about which the operation is to take place. This point is referred to as the pattern's root position. A few patterns are independent of the root position (e.g., linear patterns, and circular patterns in which the elements rotate with the pattern), but this is not generally the case. Incorrectly specifying this item can lead to unexpected results.
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Some
pattern class methods that refer to individual pattern elements do so by means of pattern coordinates. For patterns of more than one dimension, refer to the class documentation to ascertain the order in which the coordinates are to be specified. For example, in radial patterns the order is (radial, angular).
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The pattern objects are reference counted. To avoid memory leaks, call the
remove method after a pattern has been applied to an entity.
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When creating a pattern from a list of transforms, keep in mind that these items are
relative transforms. To position the first (seed) entity requires furnishing a root transformation in addition to these relative ones.
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