Curve Through More Than 3 Points

[Pointdump]

I've drawn a 3D Polyline through these points, then converted it to a Feature Line so I can use it as a Breakline in my Surface.

what I'd like is a smooth curve. A Spline Fit can't be converted to a Feature Line. A 2D Polyline uses the first point for its elevation. A 3D Polyline doesn't have any curve options. Create Feature Line is awkwardly limited to a 3-point curve. What's the best way to make a Curved Feature Line?

Dave

[Pointdump]

OK, this "Smooth" command seems to get me closer to what I want:

Dave

[Joe-Bouza]

Hi Dave

I am not in front of c3d at the moment but I think you can up the ante on the fit curve settings and use the command line option for points to go beyond the default settings?

[Pointdump]

Joe,

I was watching my command line like a hawk for just such a thing, but didn't see it.

I even thought about doing 3 points at a time with Create Feature Line, but subtleties of that command won't allow such a thing.

Dave

[Joe-Bouza]

http://docs.autodesk.com/CIV3D/2013/ENU/index.html?url=filesCUG/GUID-28547440-3EBA-42A5-AA07-C7468EB...

 points is a min. you pick start and end and can go through many more points

[Neilw_05]

I'm intrigued with this challenge. As I understand the OP, the goal is to find a best fit curve between the 2 polylines. There is a Best Fit Curve tool described in the help system but I can't find it on the ribbon or in the CUI commands list. Does anyone know how to initiate the tool?

By the way, the Best Fit curve tool won't find a best fit BETWEEN the polylines so it does not meet the task.

[Neilw_05]

One solution is to use the BEST FIT curve under the alignment tools. Once you get a curve you like, explode it down to a polyline or arc and convert to FL. From there you will have to use some method to apply elevations such as by draping on a surface created from the bounding polylines, elevation by adjacent tool, etc.

[Pointdump]

Neil,

Not a best-fit, but more like a spline-fit through my points. Instead of a segmented curve, the curb is really a series of compound and reverse curves that look almost free-form. The "Smooth" command in Edit Geometry seems to be working to do what I want.

OK, here's my new workflow:

1. Draw 3D Polyline through points.
2. Convert said 3D Polyline to a Feature Line.
3. Use "Smooth" Command to make the Feature Line look like the curve it is.

Dave

[Pointdump]

Joe,

This is an As-Built Topo, so I don't want Best-Fit. I need the curve to go through all the points, and at the Point Elevations, because I'll use the Feature Lines as Break Lines in my Surface.

Dave

[Neilw_05]

I see I misunderstood your OP. I see now you have points representing a flowline (FL) between the 2 polylines so your solution is appropriate.

[Pointdump]

Thanks, Neil,

I was hoping there was a cool command in there to Spline-Fit all those points together, but I guess not.

There is another way, but it involves using Survey Figures in the Survey Database, and I don't know if you can use a Survey Figure as a Breakline. I haven't done much with the Survey Database. I was trying to keep things Low-Tech.

Dave

[Joe-Bouza]

right. I think you will have to peice meal it

[Pointdump]

Joe,

Bam! Done!

Dave

[AllenJessup]

Dave,

I may have missed it in the thread. But did you try converting the 3D Polyline to a Featureline and then using

FITCURVEFEATURE?

The help flyout above is wrong about one thing. It doesn't work on 3D polylines. I didn't think it would so I tested it.

Allen

[rl_jackson · Accepted solution]

Dave,

There's is a cool command that does that. Use survey figures. Code you ascii file to use a the OC (on curve) figure code and all will come in as expected. Plus all you have to do is add the figures to the surface as breaklines. This can be set up on within the figure by simply checking the use a breakline.

[Joe-Bouza]

Cool. What was the ultimate work flow?

[johngordon6189]

I would just draw a polyline through the points adjusting the curvature between the known points and the turn that polyline into a feature line assigning elevations from the surface.

[jmayo-EE]

Edit the point desc to note the begining and end of curves

export the points

Import the points with a survey DB to a new file and process the linework.

You should get the curves with the linework codeset.

[Pointdump]

RL,

It took a while to setup the Database and re-order the points in the text file, but I wanted to see if OC/EC would fit to my points. It does indeed. However, the curve still looks like a segmented line. (I did a Regen All, but it didn't improve.)

Dave

[Pointdump]

John,

"I would just draw a polyline through the points adjusting the curvature between the known points and then turn that polyline into a feature line assigning elevations from the surface."

The problem is that I need those points to define the surface. (As a Breakline.)

Dave