Pesky beams

So you have a plan view with the following View Range:

which should only show elements in the shaded area:

Notice that the beams are above our view range. However in a plan view, you get this:

Why on earth are those beams showing up in that plan view? After taking a look at the properties, one might not see any issues. Upon inspecting a 3D view, the Analytical Lines don’t seem to be set correctly, however the Vertical Projection in the Properties is set to “Auto-detect”. So what gives?

The answer is at the top of the properties dialog. Notice that the beam’s Reference Level is grayed out and so is the Workplane. Now try and enter a value for the Start or End Level Offset and notice how the Workplane parameter disappears and the Reference Level is now editable. Just re-set the Start/End Level Offset to zero and alas, the analytical model will come to its senses and will start detecting the correct location. Bug? I dare say so but I’ll seek an official confirmation and post an update.

The interesting thing is that Structural Framing visibility is defined by where the analytical model is. I personally do not agree with this at all. Plan representation (in my opinion) should not be dictated by where an engineer decides he/she wants the analytical model to reside, but it should be purely based upon geometrical location. So make sure to either “touch” the Start/End Level Offset as described above if you’re only using the z-Direction Offset value, or use the other offsets instead!

Pesky beams

Beams with sloped edges

Steven Debooy, a fellow blog reader, recently asked me if it was possible to add a parameterized void at the end of a beam to cut it at a slope. That question prompted me to write this post about how one can achieve that result.

a) Adding a void to the beam is a possible solution. I posted a family in the Structural AUGI forums in 2007. Feel free to reverse engineer it and find out how it works. My example has 2 voids instead: one handles positive angles and the other handles negative angles. The user inputs an angle in one parameter, and 2 calculated parameters evaluate that input and return the correct result.

b) In the 2009 Revit family of products, one can use the Opening by Face tool to achieve the same result. Using this tool to cut the end of a beam, one will get a warning stating that "Opening partially cuts its host". It's not a serious warning (I guess), but it is meant to inform the user that something could potentially be wrong, as usually an opening is meant to have beam material surrounding the entire sketch perimeter! This is the best option if you want to create custom shaped cuts on the fly.

c) This method makes me mad. Why? Because it's only available in Revit Structure (come on people!). NOTE: As of the Subscription Advantage Pack, this functionality is also available in RAC2010. Thanks Factory!  Aaaanyway, You can sketch a reference plane and then use the Cut Geometry tool to trim the beam against the reference plane (actually you can also trim against a grid). Non-linear cuts are not possible with this technique.

Beams with sloped edges