{"action":"opened","issue":{"url":"https://api.github.com/repos/openscad/openscad/issues/1169","labels_url":"https://api.github.com/repos/openscad/openscad/issues/1169/labels{/name}","comments_url":"https://api.github.com/repos/openscad/openscad/issues/1169/comments","events_url":"https://api.github.com/repos/openscad/openscad/issues/1169/events","html_url":"https://github.com/openscad/openscad/issues/1169","id":54955675,"number":1169,"title":"Bad STL output for Prusa's ","user":{"login":"lordofhyphens","id":31754,"avatar_url":"https://avatars.githubusercontent.com/u/31754?v=3","gravatar_id":"","url":"https://api.github.com/users/lordofhyphens","html_url":"https://github.com/lordofhyphens","followers_url":"https://api.github.com/users/lordofhyphens/followers","following_url":"https://api.github.com/users/lordofhyphens/following{/other_user}","gists_url":"https://api.github.com/users/lordofhyphens/gists{/gist_id}","starred_url":"https://api.github.com/users/lordofhyphens/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/lordofhyphens/subscriptions","organizations_url":"https://api.github.com/users/lordofhyphens/orgs","repos_url":"https://api.github.com/users/lordofhyphens/repos","events_url":"https://api.github.com/users/lordofhyphens/events{/privacy}","received_events_url":"https://api.github.com/users/lordofhyphens/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-01-20T23:24:48Z","updated_at":"2015-01-20T23:24:48Z","closed_at":null,"body":"Gettting degenerate (and otherwise weird) export results when trying to build Prusa's i3 repository, particularly x-end.stl. Slic3r spots a host of manifold errors as well.\r\n\r\nPicture of glitch:\r\n![x-end-glitch](https://cloud.githubusercontent.com/assets/31754/5828380/0c92d27a-a0c9-11e4-8f1a-e8289e1bbad4.png)\r\n\r\npicture of AMF:\r\n![x-end-working](https://cloud.githubusercontent.com/assets/31754/5828392/3367a6dc-a0c9-11e4-89cd-92be3c7ac6b5.png)\r\n\r\n\r\nI think this is a regression, I don't remember having this issue with 2014.03 (or thereabouts), but the problem is there as of 2014.09 and current git HEAD.\r\n\r\nI don't see this behavior when using amf export instead (same makefile, just changed the STL file extension to AMF). \r\n\r\nsnippet from build log:\r\nGeometry Cache insert: cube(size=[36,5,14],center=true); (672 bytes)\r\nCGAL Cache insert: group(){group(){group(){multmatrix([[1,0 (117616 bytes)\r\nCGAL Cache insert: difference(){cube(size=[36,5,14],center= (69184 bytes)\r\nCGAL Cache insert: group(){difference(){cube(size=[36,5,14] (69184 bytes)\r\nCGAL Cache insert: group(){group(){difference(){cube(size=[ (69184 bytes)\r\nCGAL Cache insert: multmatrix([[1,0,0,18],[0,1,0,2.5],[0,0, (69184 bytes)\r\nCGAL Cache insert: group(){multmatrix([[1,0,0,18],[0,1,0,2. (69184 bytes)\r\nCGAL Cache insert: group(){group(){multmatrix([[1,0,0,18],[ (69184 bytes)\r\nCGAL Cache insert: group(){group(){group(){multmatrix([[1,0 (69184 bytes)\r\nCGAL Cache insert: multmatrix([[1,0,0,-6],[0,1,0,0],[0,0,1, (69184 bytes)\r\nGeometry Cache hit: multmatrix([[1,0,0,26],[0,1,0,9],[0,0,1, (3408 bytes)\r\nCGAL Cache insert: group(){group(){group(){multmatrix([[1,0 (61264 bytes)\r\nCGAL Cache insert: group(){group(){group(){multmatrix([[1,0 (37504 bytes)\r\nCGAL Cache insert: multmatrix([[1,0,0,5],[0,1,0,5],[0,0,1,0 (29464 bytes)\r\nCGAL Cache insert: group(){multmatrix([[1,0,0,-6],[0,1,0,0] (69184 bytes)\r\nGeometry Cache hit: multmatrix([[1,0,0,26],[0,1,0,9],[0,0,1, (2112 bytes)\r\nGeometry Cache hit: multmatrix([[1,0,0,0],[0,1,0,5],[0,0,1,- (1248 bytes)\r\nCGAL Cache hit: group(){multmatrix([[1,0,0,16],[0,1,0,35 (382336 bytes)\r\nCGAL Cache insert: union(){group(){group(){group(){multmatr (265344 bytes)\r\nCGAL Cache insert: difference(){union(){group(){group(){gro (602488 bytes)\r\nCGAL Cache insert: union(){difference(){union(){group(){gro (602488 bytes)\r\nCGAL Cache insert: difference(){union(){difference(){union( (602488 bytes)\r\nCGAL Cache insert: group(){difference(){union(){difference( (602488 bytes)\r\nCGAL Cache insert: multmatrix([[2.22045e-16,-1,0,0],[1,2.22 (602488 bytes)\r\nCGAL Cache hit: group(){difference(){union(){difference( (602488 bytes)\r\nCGAL Cache insert: multmatrix([[1,0,0,0],[0,-1,0,0],[0,0,1, (602488 bytes)\r\nCGAL Cache insert: multmatrix([[2.22045e-16,1,0,0],[-1,2.22 (602488 bytes)\r\nCGAL Cache insert: multmatrix([[1,0,0,10],[0,1,0,-50],[0,0, (1017200 bytes)\r\nCGAL Cache insert: multmatrix([[1,0,0,0],[0,1,0,50],[0,0,1, (1017200 bytes)\r\nCGAL Cache insert: multmatrix([[1,0,0,67],[0,1,0,14],[0,0,1 (602488 bytes)\r\nCGAL Cache insert: multmatrix([[1,0,0,77],[0,1,0,-14],[0,0, (602488 bytes)\r\nCGAL Cache insert: group(){multmatrix([[1,0,0,10],[0,1,0,-5 (3239112 bytes)\r\nWARNING: PolySet has degenerate polygons\r\n"}}