Farid Posted November 7, 2009 Share Posted November 7, 2009 I am working on vertical alignment of highways and need to draw draw a vertical, which is a parabola, in AutoCAD 2010. Anyone can help me. Quote Link to comment Share on other sites More sharing options...
ReMark Posted November 7, 2009 Share Posted November 7, 2009 What information do you have to work with? Can you share it with us? Quote Link to comment Share on other sites More sharing options...
CarlB Posted November 7, 2009 Share Posted November 7, 2009 Discussed in this thread, with link to an earlier thread. http://www.cadtutor.net/forum/showthread.php?t=28775 "Vertical curves are parabolas, you can draw them by drawing a polyline from endpoint to VPI to endpoint, then PEDIT>>Spline. For it to be a proper parabola, set SPLINETYPE to 5 before pediting, and to get a smooth curve set SPLINESEGS to 15 or higher. (Thanks to rc McSwain for the Spline/parabola info)." Quote Link to comment Share on other sites More sharing options...
Farid Posted November 7, 2009 Author Share Posted November 7, 2009 i have the equation of the parabola, and I know the begging point of the curve, the vertex, and the end point of the curve. It will be very helpful if I can plot the equation. I tried the polyline, and then changed it to spline. But changes it's positing and became smaller. Quote Link to comment Share on other sites More sharing options...
CarlB Posted November 7, 2009 Share Posted November 7, 2009 If by "vertex" you mean the high or low point of the curve, then yes the curve will be inaccurate after "pedit". it should be initially drawn as two straight segments, from start curve, VPI (intersection of tangents) (VPT) to end of curve. if you want to plot the curve, you can do the calculations in Excel, with x & y values in adjacent columns; start the pline command, copy & paste values from Excel Quote Link to comment Share on other sites More sharing options...
Farid Posted November 7, 2009 Author Share Posted November 7, 2009 yes, exactly. I mean VPI by vertex. If plot that in excel, then I think I won't be able export to AutoCAD so that I continue the further on based on what I exported. It will be only a raster image. Quote Link to comment Share on other sites More sharing options...
SEANT Posted November 8, 2009 Share Posted November 8, 2009 To expand a bit on the procedure described by CarlB: If the parabola is symmetrical, i.e., the two end points are horizontal and the vertex is above the middle of those two points, then the poly’s 2nd point should be at twice the height of the desired vertex. See Sample. Additionally, if there exists a sufficient comfort level with installing and running .NET Dlls this thread may be of interest. http://www.cadtutor.net/forum/showthread.php?t=34370 PolyParabola.dwg Quote Link to comment Share on other sites More sharing options...
Farid Posted November 8, 2009 Author Share Posted November 8, 2009 the parabolas that I am working with are symmetric. what is see in the animation will fit my work, thanks. But is it in AutoCAD? because i could read in the command line "para" and when I tried it in AutoCAD, it does recognize this command. and what is NET Dlls? Quote Link to comment Share on other sites More sharing options...
SEANT Posted November 8, 2009 Share Posted November 8, 2009 The animation demonstrates a custom routine (written in C#.NET) located in this post of that thread: http://www.cadtutor.net/forum/showpost.php?p=233991&postcount=34 To install - Download the attachment, unzip, and locate the file ParabolaByUCS\Release\CsParabola.dll. In AutoCAD: Command: Netload Then find CsParabola.dll To run: Command: pbb The routine will produce a spline. If you prefer Splined 2dPolylines, or if your IT department frowns on third party customization, the process CarlB described, and I illustrated in the DWG above, should produce useful geometry. Quote Link to comment Share on other sites More sharing options...
Farid Posted November 8, 2009 Author Share Posted November 8, 2009 Thank you Seant! I'll play with it and if I had a question, I'll again ask. Quote Link to comment Share on other sites More sharing options...
CADformat Posted April 23, 2010 Share Posted April 23, 2010 I Think I read similar topic before http://www.cadtutor.net/forum/showthread.php?t=28775 Quote Link to comment Share on other sites More sharing options...
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