# Dimensions and Tolerances

 As dimension commands work as in the Interactive Drafting workbench, this section of the documentation provides links to the Interactive Drafting User's Guide. As such, the information detailed in this section is presented in an Interactive Drafting context. You should note that the Interactive Drafting User's Guide contains images that correspond to the Interactive Drafting workbench and therefore illustrate dimensions in an environment that is different from the 2D Layout for 3D Design environment (symbols and background color, for example).Refer to Dimensioning in a 2D Layout for 3D Design Context which explains what is specific to creating dimensions in the 2D Layout for 3D Design workbench as opposed to doing so in the Interactive Drafting workbench.

 Before you begin: You should be familiar with basic concepts. Create dimensions: Create dimensions by clicking elements. Create half-dimensions: Create half-dimensions on distance, angle, diameter, cylinders, diameter edges and diameter tangents but not on cumulated dimensions. Create explicit dimensions: Create dimensions by selecting the desired icon and the required geometrical elements. Create/modify angle dimensions: Create an angle dimension and perform the following kinds of modification: new angle sector or turn an angle sector into a supplementary sector. Creating fillet radius dimensions: Create a fillet radius dimension in a projected view. Create chamfer dimensions: Create a chamfer dimension using selection. Create thread dimensions: Create associative thread dimensions. Create/modify coordinate dimensions: Automatically create coordinate dimensions on elements. Create/modify curvature radius dimensions: Create and modify a curvature radius dimension. This lets you know the curvature radius at a given point on a curve (spline, ellipse and so on). Create overall curve dimensions: You can create dimensions on the overall size of any kind of curve, whether it is canonical or not (line, circle, ellipse, spline and so on). You can also create dimensions on the overall size between two curves, or between a curve and a line, for example. Create curvilinear length dimensions: You can create dimensions for the curvilinear length of a curve, that is measure the overall length of a curve. Create partial curvilinear length dimensions: You can create dimensions for the curvilinear length of a curve portion, that is measure the partial length of a curve. Create dimensions along a reference direction: You can create dimensions along a direction of measure. In other words, you can measure the projection of a segment/distance onto a direction. Create dimensions between intersection points: You can create dimensions between an intersection point and an element or between two intersection points. Create dimensions between an element and a view axis: Create dimensions between an element and a view axis (one of the two axes or the origin). Create driving dimensions: Create dimensions that will drive associated constrained geometry. Modify the dimension type: Modify the dimension type as you create a dimension. In other words, you modify the dimension attributes. Re-route dimensions: Recalculate dimensions taking into account new geometrical elements. Interrupt one or more extension lines: Interrupt manually one or more extension lines of one or more dimensions, either using the contextual menu or the Insert menu bar command. Modify the dimension line location: Use the mouse to modify dimension line location either before or after creating dimensions. Modify the dimension value text position: Use the cursor to modify dimension value text position. Specify the dimension value position: Automatically or explicitly position the dimension value inside or outside the area between extremity symbols. Add text before/after the dimension value: Insert text before or after the dimension value. Modify the dimension overrun/blanking: Modify the dimension extension line overrun and/or blanking either together or separately. Scaling a dimension: Apply (or not) a scale to the dimension text when a scale is applied to the object containing the dimension. Line up dimensions (free space): Line up dimensions relative to a point in the free space. Line up dimensions (reference): Line up dimensions according to a given reference. Create a datum feature: Use the Datum Feature Creation dialog box to create a datum feature. Modify a datum feature: Modify a datum feature by editing it. Create a geometrical tolerance: Use the Geometric Dimensioning And Tolerancing Parameters dialog box to create geometrical tolerances. Modify a geometrical tolerance: Use the Geometric Dimensioning And Tolerancing Parameters dialog box to modify geometrical tolerances. Copy a geometrical tolerance: Copy an existing geometrical tolerance and then edit the content for creating a new one.