Adobe 12040118 Using Help - Page 174

Help Using Help Reference Back 174 Description This attribute describes an array of float pairs specifying the tangent vectors (direction handles) associated with the vertices of the shape. Each float pair specifies one inTangent. There is one inTangent and one outTangent associated with each vertex in the vertices array. However, when creating a shape to set as a keyframe value, you may leave inTangent and/or outTangent null, or you may leave entries unfilled; they will be automatically padded with zeroes. This will result in straight line segments in the non-RotoBezier case; in the RotoBezier case the zeros will be ignored and the inTangents/outTangents will be automatically calculated. Each vertex on the shape has two direction handles. The outTangent is the direction handle associated with the line segment 'going out of ' the vertex toward the next vertex in the shape. The outsTangent are x,y coordinates specified relative to the associated vertex. For example, an inTangent of [-1,-1] is located above and to the left of the vertex, and has a 45 degree slope, regardless of the actual location of the vertex. The longer a handle is, the greater an influence it has, so an incoming shape segment will hug the tangent vector closer for an inTangent of [-2,-2] than it will for an inTangent of [-1,-1], even though both of these come toward the vertex from the same direction. If a shape is not closed, the inTangent for the first vertex and the outTangent for the final vertex will be ignored. These two vectors would otherwise specify the dirction handles of the final connecting segment out of the final vertex and back into the first vertex. Note that if a shape is used in a mask with Rotobeziers, then the tangent values will be ignored on write (i.e., ignored when you set the new shape), because RotoBezier masks calculate their tangents automatically. This means that, for RotoBezier masks, you can construct a shape by setting only the vertices attribute and setting inTangents and outTangents both to null. If you set the shape without tangents, then follow this by getting the shape once again, the new shape's tangent values will be filled with the automatically-calculated tangent values. Type Array of floating-point pairs; read/write. Shape Shape() method New Shape() Description This method is the constructor to create a new shape. After constructing a shape with this method, set the various attributes individually to fill the shape with desired values. Parameters None. Returns Shape. Shape vertices attribute Description This attribute describes an array of float pairs specifying the anchor points of the shape. Each float pair is an array of two floats. Using Help Back 174