On the surface, it seemed like something pretty easy to do. While in Sketch Mode for the masking region, you can select the boundary line you want to paramaterize to control its visibility and add a Yes/No field to it. You can check out the accompanying image to see how I attempted this. Seems like it would do the trick, right?
The problem is that it just flat doesn’t work. For some reason, the Visibility parameter doesn’t apply to masking region boundaries. I fought with the masking region a bit before eventually, I figured out a pretty easy work around. It was one of those things I figured out while deep in the middle of a family creation project that saved the day, but I didn’t take the time to put together a blog post or video to share it with my fellow Reviteers.
Well, Jose over at Andekan has created a great (while lengthy) video showing the problem and the work around. Check it out, after this brief description of the solution. Here’s the trick:
You can’t control the visibility of a Revit masking region boundary with a parameter.
Instead, change the linework of the boundary lines that you need to control to ‘Invisible’. Now they will never be seen. Exit sketch mode for the masking region.
Next, draw new Symbolic Lines over the top of them. Guess what? Symbolic Lines CAN have a parameter that controls their visibility!
You should be able to take it from there. If you want to see a great step by step, check out the video from Andekan. Also, be sure to check out their high quality custom Revit families. These guys do a great job of creating powerful and parametric Revit content.