You need to make a hole in your floor for the rug That weird occurance is called Z-fighting. In DromEd, it was fine to have 2 overlapping solids. The one last in the order would show. In Radiant, you need to make a hole. So, resize your floor, copy it and make 4 segments leaving a hole in the middle instead of just one floor. Then make a brush with the rug texture and make sure it exactly fits the gap.