These are some of my first renders using Carrara. Much of it was modeled in Rhino.

This was designed to play with light through the openings in the ceiling falling on the floor. Then I decided to raise it up and add columns, the I decided I wanted to carry the stair-stepped theme to the front and back edge of the arced roof. That turned out to be a very difficult exercise in visualization. But I am happy to say I stick with it and finally got exactly what I wanted through a complex process of booleans. The problem is I have created a monster that can not be shown off completely from any angle. So I will probably do an animated fly-through once I am happy with the scene. All three renders are using the same textures, only the lighting has changed. Notice how different the shader on the arch looks in the two renders on the right. I am still very disappointed in Carrara's procedural checkers pattern. I tried several things that Antoine suggested including the idea that the problem was infinite planes. This floor is clearly not an infinite plane, I turned off light smart sampling and used the full Raytracer. In the image on the right I am even at a fairly high angle but the edges of the pattern still look very ragged. Antoine suggested creating a checker pattern bitmap. That is probably the best bet.
       

This was meant to be a big awning-like structure covering a large outdoor dining area like at a state fair but I had trouble getting the feet to look strong yet at the right scale so now it looks like a park bench so I rusted it. The shiny version is more to my liking.