public void AppendFacets() { STLDocument stl1 = null; STLDocument stl2 = null; int facetCount = 0; using (Stream stream = GetData("ASCII.stl")) { stl1 = STLDocument.Read(stream); stl2 = STLDocument.Read(stream); } ValidateSTL(stl1); ValidateSTL(stl2); facetCount = (stl1.Facets.Count + stl2.Facets.Count); stl1.AppendFacets(stl2); ValidateSTL(stl1, facetCount); }