How to use the function ProSurfaceTessellationGet
My program is as follow:
ProSurfaceInit(owner,model_item.id,&surface);
ProSurfacetessellationinputAlloc(&input);
ProSurfacetessellationinputStepsizeSet(input,0.02);
ProSurfacetessellationinputChordheightSet(input,0.01);
ProSurfacetessellationinputAnglecontrolSet(input,0.0);
ProSurfacetessellationinputUvprojectionSet(input,PRO_SRFTESS_DEFAULT_PROJECTION,NULL);
ProSurfaceTessellationGet(surface,input,&tessellation);
ProTessellationVerticesGet(tessellation, &p_points);
when the program go on the function ProSurfaceTessellationGet ,there is something wrong,PRO_TK_GENERAL_ERROR,see the online help ,it means The function could not generate the tessellation for the input surface.
it bothers me for several days,so I really really need someone's help.

