In order to create a dimension representing a distance between a point on a curve and a projection of said point onto another curve, upon calling the Dimension command, sequentially select two lines - the initial curve and the curve where the point will be projected to, by pressing them with . The initial curve may be a 2D path, spline/polyline (sketch or construction), offset curve (sketch or construction), or function. The second curve may be of any type.
Upon selecting the second curve, the system finds the point on the first curve nearest to the current cursor position and projects such point onto the second curve in direction normal to the second curve. Then the distance between the point and the projection is measured in direction normal to the first curve.
The preview of the dimension appears. It is dynamically updated in accordance with the cursor position. Dimension line and value positioning and dimension symbol options become available in the automenu. Set the desired configuration of the dimension by moving the cursor, and confirm the input by pressing or <Enter>. In result, points and direction of measurement will be fixated. The dimension line will start following the cursor along the imaginary straight line tangent to the first curve at point of measurement, and dimension value will start following the cursor along the dimension line. Set the desired positions of dimension line and value, and confirm the input by pressing or <Enter>. The dimension will be created. Upon creating a dimension, the command returns to initial state.
1 - cursor position
2 - shortest distance between the cursor position and the red spline
3 - point of the red spline nearest to the cursor position
4 - straight line tangent to the red spline at point 3
5 - straight line normal to the green spline and passing through the point 3
6 - projection of the point 3 onto the green spline
7 - straight line tangent to the green spline at point 6
8 - direction of measurement