Autodesk 235B1-05A761-1301 User Guide - Page 675

Point Reference Defined by a point in the work plane that is based on a source point selected from a different work plane. A point reference is moved or deleted with the source point. Project Geometry Defined by a projection of a modifier on a specified work plane. The project geometry is fixed and cannot be moved in the work plane. It is linked to the modifier and adjusts as the modifier changes. Dimensions Models require dimension information to maintain size and position for the design. Dimensions are typically added after you have finalized the geometric features of the model or when placing a connector; however, you can add dimensions at any time during the creation process. When you add dimensions, you apply rules that control the size and position of features in the model. Dimensions work in conjunction with constraints. The model is updated when changes are made to the dimensions. Dimensions specify the length, diameter, or rotation angle of geometric elements in the model. When a dimension is added, a corresponding size parameter is also added. This parameter creates a placeholder value for the dimension that provides flexibility for defining the values of dimensions. Dimensions can be defined as default numeric constants or as equations. Although you can use them interchangeably, they each have specific uses. ■ Numeric constants are useful when a geometric element has a static or fixed size that is populated as a value in a basic table, list, or constant storage type. ■ Equations are useful when the size of a feature icon must be mathematically defined relative to the size of another feature. Content Builder assigns a variable name to each dimension parameter. Letters and numbers are used to signify the type of dimension (such as length or diameter) and the sequence in which the dimension was added to the model (1 for first, 2 for second, and so on). To keep the model shape from becoming distorted as the dimensions resize it, define the large dimensions first. Dimension type depends on the feature you choose and where you place the dimensions. NOTE When adding dimensions it is recommended to select points to specify the start and end locations. It is also helpful to turn off geometry that you are not dimensioning for ease of selection. Viewing dimension types Content Builder provides 7 types of dimensions you can add to the model: Distance Can be defined for pairs of geometry of all types. Defines a value between 2 features. The value of a distance dimension cannot be negative. When adding distance dimensions between 2 lines, it is implied that the lines are parallel with a given separation. Horizontal Distance Can be defined for pairs of geometry of all types. Defines a value between 2 features in a horizontal direction. The value of a distance dimension cannot be negative. Vertical Distance Can be defined for pairs of geometry of all types. Defines a value between 2 features in a vertical direction. The value of a distance dimension cannot be negative. Building Parametric Fittings Using Content Builder | 657