A method, apparatus, and medium for transforming a graphic data of an object and a computer readable recording medium storing a program for executing the method are provided. The method includes; determining at least one triangle to be collapsed among one or more triangles comprised in the object, determining a collapsing vertex to be created by collapsing the at least one triangle, and transforming the graphic data of the object based on information regarding the at least one triangle determined to be collapsed and information regarding the determined collapsing vertex. Thus, a large three-dimensional object can be efficiently rendered with a small amount of resources.