To limit the type of changes allowed to a group of objects you can apply geometric constraints. Examples of geometric constraints are Horizontal, Vertical, Parallel and Perpendicular.
Transcript of this video
Welcome. I’m Cindy Dunn, President of CCAD inc. Generally, AutoCAD objects can be freely modified with few limitations, like this polyline created with the RECTANG command.
To limit the type of changes allowed to a group of objects you can apply geometric constraints. Examples of geometric constraints are Horizontal, Vertical, Parallel and Perpendicular
I’ll show you how to apply these constraints to a polyline created with the RECTANG command.
Start by choosing the RECTANG command and picking two points. Click one of the grips to see how unconstrained the polyline is.
Select the Parametric tab, choose the Horizontal constraint and apply it to one of the edges. Notice the icon or glyph that is displayed. Don’t worry, it won’t print. The edge of the polyline with the constraint remains horizontal no matter how the polyline is stretched.
The Parallel constraint insures that two edges remain parallel to each other. I’ll make the bottom edge parallel to the top. Two parallel glyphs are displayed. Hover over one of the glyphs to see the mating glyph.
To make sure the polyline remains a rectangle, I’ll add another parallel constraint and then a perpendicular constraint.
No matter how I stretch the polyline it retains its rectangular shape.
But what if I want to rotate the polyline?
Ahhh, that first constraint requires that the edge remain horizontal. I’ll delete the horizontal constraint so the polyline can be rotated.
When using constraints you can hide or show all the constraints or hide/show selected constraints. You can also Auto Constrain selected objects or turn on Infer Constraints to have determine which constraints to apply as you draw.