Recently when creating families in Revit, I came across a problem. When creating a square extrusion, lets use for this example a table top. If you want to have curved edges on the front and back edge of the table, it is possible to draw your extrusion in an elevation view e.g. Elevation left, as shown below. What you will achieve is, as you would expect a rectangle extrusion with rounded edges as you have drawn the profile in the elevation.
But what happens, if you want to turn the other 2 flattened off edges on either side in to a rounded edge? I thought this would be easily achieved by going to the front elevation view as you see below and editing the extrusion and then modifying the profiles of the edges on both sides in the same way I have done when I created the original extrusion. Unfortunately, this is for some reason not possible and Revit gives you a dialogue box where you are forced to change view if you want to edit the extrusion. It is therefore only possible to edit the extrusion in a Left or Right Elevation view as shown below. This will not help us as it is the same view in which the original element was created.
I therefore tried various workarounds, and achieved a solution through the use of void extrusions. Open up the front elevation view where you want to add the profile and draw a square exrusion in the corner of extrusion you are editing baring in mind the dimensions of your model. After this, use a tangent arc to join the edges and create a curved profile as you see below. Draw the extrusion exactly as you see it and make sure that it is formed in a closed loop.
Once you have created the Void Extrusion, you will see that it is a small block in the centre of your original extrusion. You now need to apply the rounded edge over the whole edge of the table top. You can do this by navigating to your left elevation view where you can stretch your new void extrusion so it is covering the corners of your table top surface. This will now create a neat joined surface with curved edges on all sides.
As shown below, this is a valid work around, and can still be locked to work planes to create a parametric surface. Although it gives the result I was looking for, I am sure there must be a better method to achieve the same results. I tried it with all the modelling tools and this was the best outcome that I could come up with.
If anyone knows of a better method to do this, please let me know as I would love to know an easier way to achieve this fairly common type of finish for furniture etc. Leave a comment and I will get back to you ASAP.