The sample drawing contains an example of countours all placed in the zero elevation, Z=0. The CHELEV.LSP file can be downloaded from Download. Just pick two points connecting a line climbing across the contour set and specify the bottom elevation and the contour step. The LISP utility CHELEV (command CHELEV) can easily assign proper elevation (Z) to a set of contours. But a simple LISP utility can simplify generating a terrain model in AutoCAD Civil 3D or AutoCAD.Ī sample data can be download from the drawing file LOM. You obviously cannot directly generate digital terrain model (DTM, topo) from such source data.
If you need to use a supplied survey data to create a 3D terrain model (DTM) you can sometimes find that the input data are just 2D contours (polylines) without any assigned elevation (Z-coordinate) - just a flat plan view. OR, you could get Civil 3D which does it all and more.Assigning elevations to 2D contours (isolines). IMHO, the mtext method with backgroundfill is far superior because you don't break any contours and you can move the label and still have it mask the contour. Instead create the text and then use the TRIM command selecting the text as the cutting edge, and then the original result of (entsel) in the format '( (x y z)) as the object to trim. don't try to use a circle and then trim inside of it. One important recommendation if you wish to break the contour on each side of the text. I have code to either use text or mtext that I can provide you if you want, but you appear capable of figuring this out yourself. Instead we use DVIEW TWist, which complicates your text orientation more, as you have to adjust for the twist angle.Ī) trimming the contour on either side of the label (as was the days before mtext backgroundfill), or First of all, there's no guarantee that your circle will intersect with a polyline, especially if it intersects the same bulged segment twice.Ģnd, if it does intersect twice, the order of the returned intersection points may not create an angle that is "right side up." But you could check for that by comparing the x values of the two points and swap the direction if needed.ģrd, if you do as most of us civils do, we don't rotate the world to orient our plan to the border.
0 kommentar(er)
