Here is how the 3-D pinwheels are made.
Fold the pinwheel blade square in half to make a triangle, in whichever direction you want your pinwheels to be 'spinning.'
Start with 2 squares, one for the background and one for the blades of the pinwheel.
Turn the lower corner of the blade triangle back to the long side of the blade, and now you have one blade of the four that go to make a block. You can baste the sides if you like, or you can just pin the pieces so that the edges of the pinwheel blade are caught in your 1/4" seams.
Here's what they look like on the quilt. Note the pinwheels are 'spinning' the other way on this quilt, from what I show in my example.
This is the completed assembly and quilting of that particular quilt.
Place the folded blade fabric on the background fabric in the corner appropriate to your chosen direction of 'spin.' Quilting is all about options!