Andy, I reproduced your problem using a version of CGM that I built on Cubit13.1. After some experimentation, I think that the problem is that the GeometryType is off by one in CGMA from what the Cubit library expects. I got successful RefFaces when passing arguments CONE_SURFACE_TYPE (which I am guessing is interpreted as the one-later enum value PLANE_SURFACE_TYPE) and TORUS_SURFACE_TYPE (which I am guessing is interpreted as the one-later enum value BEST_FIT_SURFACE_TYPE). We ought to fix the off-by-one error, but for now just the information I’ve given will probably help you with whatever you are doing. I’m not sure which value would have to be removed/renumbered to get CGMA to agree with Cubit. Is anyone else familiar with the GeometryType enumeration? I’m just making my best guess here . . . -Evan From: Vander Zee, Evan B. Sent: Monday, July 27, 2015 4:48 PM To: [email protected] Cc: Patrick Shriwise; 'Andrew Davis' Subject: RE: [cgma-dev] Why can't I create surfaces from curves It is a little hard to tell exactly what you are trying to do, but it looks like you are trying to create a circular patch in the y-z plane. I tried running the code you provided with OCC geometry engine, and I got no errors. Some things you could try would be giving more than two edges and linking edges better in a loop, i.e., making sure that the end vertex of one edge is the beginning vertex of the next. I planned to try these, but my only successful build of CGM with acis so far is a cmake build, and I’m still a novice in the cmake build system, so I didn’t get far enough to reproduce the problem. What version are you using? -Evan From: [email protected]<mailto:[email protected]> [mailto:[email protected]] On Behalf Of Andrew Davis Sent: Monday, July 27, 2015 10:01 AM To: Patrick Shriwise Cc: Andrew Davis; [email protected]<mailto:[email protected]> Subject: Re: [cgma-dev] Why can't I create surfaces from curves Hi Patrick Irrespective of whether or not I use planar, best fit, sphere, its the same error message over and over again. Thanks Andy On Sat, Jul 25, 2015 at 8:00 AM, Patrick Shriwise <[email protected]<mailto:[email protected]>> wrote: Hey Andy, The error message seems to indicate it's trying to make a surface which isn't planar.. maybe thats a good starting point? Are there other flags to hand that function by chance? Cheers, Patrick On 07/23/2015 02:34 PM, Andrew Davis wrote: Hi Guys I have the following function that I've added to my version of iGeom, ITAPS_API void iGeom_createSurface2(iGeom_Instance instance, /*in*/ iBase_EntityHandle *input_curves, /*in*/ int num_curves, /*out*/ iBase_EntityHandle *geom_entity, int* err) { CubitVector p1(0, 0, 5); RefVertex* v1 = gmt->make_RefVertex(p1); CubitVector p2(0, 0, -5); RefVertex* v2 = gmt->make_RefVertex(p2); CubitVector p3(0, 5, 0); RefVertex* v3 = gmt->make_RefVertex(p3); CubitVector p4(0, -5, 0); RefVertex* v4 = gmt->make_RefVertex(p4); RefEdge* e1 = gmt->make_RefEdge(ARC_CURVE_TYPE,v1,v2,&p3); RefEdge* e2 = gmt->make_RefEdge(ARC_CURVE_TYPE,v1,v2,&p4); DLIList<RefEdge*> curves; curves.insert(e1); curves.insert(e2); RefFace* tmp_surface = gmt->make_RefFace(PLANE_SURFACE_TYPE, curves, false); *geom_entity = reinterpret_cast<iBase_EntityHandle>(tmp_surface); RETURN ((tmp_surface ? iBase_SUCCESS : iBase_FAILURE)); } When I run this, I can sucessfully create the vertices, and create curves from those verts using make_RefEdge. When I try to create a surface from those two ref edges I get the following error. WARNING: In AcisGeometryEngine::make_FACE At this time, cannot make a FACE that isn't planar or best fit. ERROR: In AcisModifyEngine::make_Surface Cannot make Surface object. ERROR: Couldn't make new RefFace. If I save the file as acis and examine the results in Cubit, they appear as they should (minus the surface). I can, in Cubit, make surface then, sweep and do all the operations that I want to. Is there something that I', just misunderstanding about CGM / gmt that means I'm using this wrong? Thanks Andy