I used the dome tool and selected the constant height function. Since I would route the piece from a three inch thick Precision Board I entered a value of 2.6″ I would tweak it just under the final dimension of 3″ (top surface of piece) at the last minute.
The rectangle was made into a relief of zero height.
Then I opened the merge function. I selected the circle first, then followed the prompts to merge LOWEST.
To get rid of the unwanted pieces of the relief I used the slice function, effectively slicing the bottom of the relief off.
As EnRoute does this it leaves the original relief intact. I selected this one and moved it off to the side.
The sun rays were cut in two layers with slots cut in one of the layers for a welded steel frame. The three layers would be laminated together.
-dan