{"action":"created","issue":{"url":"https://api.github.com/repos/openscad/openscad/issues/1435","labels_url":"https://api.github.com/repos/openscad/openscad/issues/1435/labels{/name}","comments_url":"https://api.github.com/repos/openscad/openscad/issues/1435/comments","events_url":"https://api.github.com/repos/openscad/openscad/issues/1435/events","html_url":"https://github.com/openscad/openscad/issues/1435","id":105126563,"number":1435,"title":"Faces that are not on the same plane in polyhedron should be autosplit into triangle faces.","user":{"login":"robertmassaioli","id":149178,"avatar_url":"https://avatars.githubusercontent.com/u/149178?v=3","gravatar_id":"","url":"https://api.github.com/users/robertmassaioli","html_url":"https://github.com/robertmassaioli","followers_url":"https://api.github.com/users/robertmassaioli/followers","following_url":"https://api.github.com/users/robertmassaioli/following{/other_user}","gists_url":"https://api.github.com/users/robertmassaioli/gists{/gist_id}","starred_url":"https://api.github.com/users/robertmassaioli/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/robertmassaioli/subscriptions","organizations_url":"https://api.github.com/users/robertmassaioli/orgs","repos_url":"https://api.github.com/users/robertmassaioli/repos","events_url":"https://api.github.com/users/robertmassaioli/events{/privacy}","received_events_url":"https://api.github.com/users/robertmassaioli/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":6,"created_at":"2015-09-07T00:44:27Z","updated_at":"2015-09-07T02:18:18Z","closed_at":null,"body":"To see a better description of this issue view this StackOverflow question: http://stackoverflow.com/questions/32428638/openscad-do-polyhedron-faces-have-to-be-on-the-same-plane\r\n\r\nI think that the problem is that using polyhedron with quad faces that do not lie on a plane causes issues when you try and generate an STL file but not in the preview window.\r\n\r\n<bountysource-plugin>\r\n---\r\nWant to back this issue? **[Post a bounty on it!](https://www.bountysource.com/issues/26492624-faces-that-are-not-on-the-same-plane-in-polyhedron-should-be-autosplit-into-triangle-faces?utm_campaign=plugin&utm_content=tracker%2F52063&utm_medium=issues&utm_source=github)** We accept bounties via [Bountysource](https://www.bountysource.com/?utm_campaign=plugin&utm_content=tracker%2F52063&utm_medium=issues&utm_source=github).\r\n</bountysource-plugin>"},"comment":{"url":"https://api.github.com/repos/openscad/openscad/issues/comments/138159853","html_url":"https://github.com/openscad/openscad/issues/1435#issuecomment-138159853","issue_url":"https://api.github.com/repos/openscad/openscad/issues/1435","id":138159853,"user":{"login":"robertmassaioli","id":149178,"avatar_url":"https://avatars.githubusercontent.com/u/149178?v=3","gravatar_id":"","url":"https://api.github.com/users/robertmassaioli","html_url":"https://github.com/robertmassaioli","followers_url":"https://api.github.com/users/robertmassaioli/followers","following_url":"https://api.github.com/users/robertmassaioli/following{/other_user}","gists_url":"https://api.github.com/users/robertmassaioli/gists{/gist_id}","starred_url":"https://api.github.com/users/robertmassaioli/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/robertmassaioli/subscriptions","organizations_url":"https://api.github.com/users/robertmassaioli/orgs","repos_url":"https://api.github.com/users/robertmassaioli/repos","events_url":"https://api.github.com/users/robertmassaioli/events{/privacy}","received_events_url":"https://api.github.com/users/robertmassaioli/received_events","type":"User","site_admin":false},"created_at":"2015-09-07T02:18:18Z","updated_at":"2015-09-07T02:18:18Z","body":"Okay, it almost works perfectly now. Only one issue left:\r\n\r\n![screen shot 2015-09-07 at 12 16 47 pm](https://cloud.githubusercontent.com/assets/149178/9708104/5ecaeea6-555a-11e5-927c-0ca9836f3e38.png)\r\n\r\n    Compiling design (CSG Tree generation)...\r\n    Rendering Polygon Mesh using CGAL...\r\n    PolySet has nonplanar faces. Attempting alternate construction\r\n    PolySet has nonplanar faces. Attempting alternate construction\r\n    PolySet has nonplanar faces. Attempting alternate construction\r\n    PolySet has nonplanar faces. Attempting alternate construction\r\n    ERROR: Alternate construction failed. CGAL error in CGAL_Nef_polyhedron3(): CGAL ERROR: assertion violation! Expr: e->incident_sface() != SFace_const_handle() File: /Users/kintel/code/OpenSCAD/openscad-2015.03/../libraries/install/include/CGAL/Nef_S2/SM_const_decorator.h Line: 326 \r\n    PolySet has nonplanar faces. Attempting alternate construction\r\n    PolySet has nonplanar faces. Attempting alternate construction\r\n    PolySet has nonplanar faces. Attempting alternate construction\r\n\r\nI think that the error is the Alternate construction failed line that makes one whole polyhedron not show. So I'm looking into that now. :)"}}