within the surface element along the curvature of rounded surface b triangular surface element f 4 which continues the approximation of continuously curved rounded surface b toward f 3 contains vertices f 41 e 42 and e 43 with vertices e 41 and e 43 of surface element f 4 coinciding with vertices e 32 and e 33 of surface element f 3 and the sides of the surface elements connecting the vertices because a continuous color shading transition is desired for rounded surface b the energy value triplets of e 33 and e 43 are selected to be identical for example a common average surface normal orientation or a surface normal orientation derived from the rounded curvature of b itself can be used for vertices e 33 and e 43 likewise the energy value triplets for vertices e 32 and e 41 are identical while energy value triplet r 42 g 42 b 42 of vertex e 42 of the surface element differs at least from the energy value triplet of vertex e 41 and in the illustrated example also typically differs from the energy value triplet of vertex e 43 because the energy value triplets at coincidental vertices of adjacent surface elements are identical a continuous color shading transition is obtained which provides a smooth visual impression even with a rough approximation of the continuous curvature only the coordinates of the vertices and the corresponding energy values are transferred from the cpu to the graphics card where the energy values of all pixels in the two dimensional object representation are calculated by interpolation preferably by linear interpolation from the transferred energy values of the vertices consequently this also.