I came across a Revitcity.com technical support forum with a discussion on how to create a pyramid. I don't usually participate in discussion threads but for this topic, I made an exception. I've seen a lot of Revit users offer various solutions on how to create a pyramid. Some of the methods they use are: using solid blends or using voids to carve the shape. Here is the solution I posted at Revitcity.com:
"A pyramid is a simple sweep in Revit. If you’ve used the sweep tool to generate say a baseboard, you’ll notice that when your path turns to a 90 degree angle, the corner of the sweep gets mitered. In effect, a pyramid is just a plain sweep with a triangular profile mitered at four sides on its square path."
Here is how it's done:
1. Using the solid sweep tool, create a square path in Plan view (Figure 1):
2. Go to the Front elevation view and draw a triangular profile (Figure 2). Click Finish.
That's it! Here's the 3D view (Figure 3):
If you want to get a parametric version I made, go to this Revitcity link: