Inserting a PVI at a non-collinear element would be required and expected. But I'm not sure how adding a PVI prior to each circular vertical arc helps since no one else is writing the data out that way! R. W. Bradshaw -----Original Message----- From: landxml-bounce@xxxxxxxxxxxxx [mailto:landxml-bounce@xxxxxxxxxxxxx] On Behalf Of Martin Pineault Sent: Thursday, April 26, 2007 8:50 AM To: 'Daniel Lidström' Cc: landxml@xxxxxxxxxxxxx Subject: [LandXML] Re: Calculate height at start of ParaCurve So LandXML should review there vertical alignment design to use the same element method like the horizontal alignment! Anyone listening from LandXML group? Thank you. Martin Pineault Directeur Informatique OSG Inc. -----Original Message----- From: Daniel Lidström [mailto:daniel.lidstrom@xxxxxx] Sent: 26 avril 2007 09:35 To: 'Martin Pineault' Subject: SV: [LandXML] Calculate height at start of ParaCurve Martin Pineault scribbled: > No problem, > > Yes, what I need is the starting point of the parabola is not on the > line done by previous PVI and the PVI of my parabola. It's not > collinear like in horizontal element. So you think we should just > add a PVI with no length at the same position than the starting point > of the parabola. This is ugly by the way; we will end up with to > point on the same position? Exception case handling in the way!! Aha, yes we have the same problem. Our system does not use PVI, but instead we store start point of each vertical element. So when writing LandXML I just put a PVI where each vertical element begins. It is an ugly solution, but that is inevitable when storing tangent points instead of intersection points. Here is what happens: This nice vertical alignment: <PVI>396560 61.83</PVI> <CircCurve radius="50000" length="75.0000270250073">396654.000021376 61.8298749849364</CircCurve> <CircCurve radius="50000" length="150.00005625405154">397214.069000002 62.6705001265687</CircCurve> <CircCurve radius="50000" length="424.98430684170251">398470.588193339 61.6940460906159</CircCurve> <CircCurve radius="20000" length="399.98666596623877">399144 54.9601000075043</CircCurve> <CircCurve radius="30000" length="599.980998999281">400708.9925 70.6098599892529</CircCurve> <CircCurve radius="40000" length="279.98748692798614">403042.899315129 47.2710531459537</CircCurve> <CircCurve radius="40000" length="120.00004499956418">404166.5177975 43.9000000000015</CircCurve> <PVI>404226.518 43.9</PVI> when read by Geo and saved as LandXML, becomes this: <PVI>396560 61.83</PVI> <PVI>396616.4435 61.8299</PVI> <CircCurve radius="50000" length="75.113">396654.000022204 61.8298401712956</CircCurve> <PVI>396691.5565 61.8862</PVI> <PVI>397157.118 62.585</PVI> <CircCurve radius="50000" length="113.902">397214.068976536 62.6704683743444</CircCurve> <PVI>397271.02 62.6262</PVI> <PVI>398240.0291 61.8732</PVI> <CircCurve radius="50000" length="461.1067">398470.588178474 61.6940236793394</CircCurve> <PVI>398701.1358 59.3886</PVI> <PVI>398944.0136 56.9599</PVI> <CircCurve radius="20000" length="399.9728">399144 54.9600720104529</CircCurve> <PVI>399343.9864 56.9599</PVI> <PVI>400409.0108 67.6101</PVI> <CircCurve radius="30000" length="599.9635">400708.9925 70.6098839858111</CircCurve> <PVI>401008.9742 67.6101</PVI> <PVI>402902.918 48.6709</PVI> <CircCurve radius="40000" length="279.969">403042.899315615 47.271095144993</CircCurve> <PVI>403182.887 46.8511</PVI> <PVI>404106.5147 44.08</PVI> <CircCurve radius="40000" length="120.0065">404166.517829586 43.8999900034323</CircCurve> <PVI>404226.5212 43.9</PVI> <PVI>404226.518 43.9</PVI> Exception cases very likely! :-) Hälsningar, Daniel SBG AB Phone: +4687112090 Fax : +4687112098 Location: 59 14'10" N 18 00'09" E __________ NOD32 2220 (20070426) Information __________ This message was checked by NOD32 antivirus system. http://www.eset.com