Hi I create a ModelEntity with radius equals 1. When I ask for the radius of a sphere with this sentence: let radius = sphere.visualBounds(relativeTo: elemento).boundingRadius radius takes value 1,73205... Doc says about this var boundingRadius : The radius of a bounding sphere that encompasses the bounding box. (Undefined if empty.) https://developer.apple.com/documentation/realitykit/boundingbox Hence, I think it should be 1 because the sphere I created is with a radius equals 1, why returned value is 1,73205 ? Diving this value I realize it is Vesica Piscis value https://en.wikipedia.org/wiki/Vesica_piscis