Tuesday, October 17, 2006

Reference Planes in Families

When creating parametric families we've found that the best way to control the dynamic geometry is to create a skeleton of reference planes to which dimensional parameters are attached. Once the skeleton works as expected we create geometry that we attached and lock to the reference planes. However recently we've discovered one minor issue that family authors should be aware of when using reference planes in creating families. On several occasions we've had symbolic geometry randomly showing up in views where it shouldn't. For instance an interior elevation had casework door elevation swing lines showing up when the cabinets were on the other side of the wall (see figure to right). Or, we've had door elevation & plan swing lines show up in views where the door isn't visible. The culprit in all cases has been "extra" reference planes that aren't being used in a family. What makes it even harder to track down is the offending reference planes are often in nested families. In both cases of the casework doors and regular doors it was a piece of hardware that was causing the problem. The hardware was created a "generic model" and the template used included some pre-defined reference planes that weren't required for the handle, because the reference planes were pre-defined they couldn't be deleted, and the author simply left the planes where they were. In the case of the handle, even though the planes were only a couple of feet away (see the figure bottom right) from the origin the handle was so small that it caused problems. In this case the solution was to move the reference planes in extremely close to the geometry so as to stop causing problems.


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