Smart dimensions

"Smart dimensioning" system. This means it's possible to define a line's relationship to another line (distance, angle, and relative length are the main ones). It's possible to define all of a shapes relative distances until there is some indicator that the shape is "completely defined" - this means that all dimensions are in relation to a known "driving" dimension. Also, It's possible to change the dimension of an object by clicking on it's visual smart dimension.

Blender 3D ruler tool could be used for implementation of smart dimensions:

In the T panel click on ruler and protractor button, then click on screen and create the ruler. Click on the middle and move to change it to a protractor to measure angles. You can use Ctr to snap and Supr or Esc to delete the ruler/protractor."

Latest additions to the ruler (button in T panel, Enter to store it in a grease pencil layer, click and drag to create one) http://projects.blender.org/scm/viewvc.php?view=rev&root=bf-blender&revision=55089 http://projects.blender.org/scm/viewvc.php?view=rev&root=bf-blender&revision=55120