Centerline Curve Between Two Curves

Hi!

To get this discussion started; the only way that I can think of at this time, to do this using Microstation alone is to draw a series of lines between points on either curb element (creek sides) and then draw a curve string, b-spline (thru points), linestring from the mid-points on each line you drew between the curbs / creek sides. There is no simple tool that I can think of at this time.

You could get fancy by gathering points along each side dumping them out to excel, creating an averaging formula for the values and coming up with a series of coordinates you can dump back into MicroStation as vertices of a curvestring/linestring/bspline You could also do this using VBA. Best bet would probably create a VBA to do this.

I agree with George's first option where you would draw a series of lines between each curb and produce another "curb element" between the mid-points. The problems I can see here would be how the lines drawn between each curb line are going to be estimated. Are you going to use a Perpendicular Snap between lines or just guess-timate where to place them?

With the below screen capture I have two b-spline curves that are clearly not parallel. Using the Perpendicular and Near Point Snaps I have placed lines between these two curves. They are not exactly accurate but just visually perpendicular between them. I have then used the B-Spline By Tangents tool with a Mid Point Snap to place a "centre line" between these two. It is probably not exactly accurate but looks close to what is being requested.

I would think that if you are wanting to perform an operation that is related to road or civil design that you should be using a software package designed for that purpose. The link you provided shows that it can be performed using the tools designed for InRoads. These tools, as you realize, are not included in the base package of MicroStation. Sometimes the complexities of a particular work flow might be better handled with a software package designed for the situation. Rather than redesigning or reprogramming.

I confirm I was using SS3, as for the Extract Iso-Curves tool bring up the Attach Cell Reference not sure. What happens if you use the keyin ' EXTRACT ISOLINE ' rather than the tool?

Same thing.

Tasks button;

Toolbar button;

Tools|Surfaces|Surface Utilities|Extract Iso-Curves;

"EXTRACT ISOLINE" keyin.

...all open the Attach Cell Reference dialog.

Plus, Under Tools|Customize, following the Application Tools tree under the Tools tab down to "Extract Iso-Curves" also shows it is using the proper "extract isoline" keyin.  So, I don't know.

Might be a config thing?

YEA Carl!

I thought you could do something like that, but I couldn't find it! We don't do a lot of 3D modeling work typically, so I have to try to remember (keeps me in practice). I did it once over a year or so ago, but couldn't find it it to answer quickly!

I tried this in a clean install of MicroStation V8i SELECTseries 2 also and do not see the same problem as yourself using the delivered workspace ' Untitled '. This to me suggest that its workspace specific as you hint, may be you could try the ' Untitled ' delivered workspace to see if you still have the same issue for verification.

At the start of this thread you also mentioned 'Inroads' perhaps the problem is related to another application installed that's causing conflict.

If still unable to identify the cause I suggest you start another post including an image of the dialog that appears as this is off the original topic.

Thanks

I did it another way years ago for finding the river centre between banks I did it with placing  several circles by two points makes it easier to find the centers for the bspline curve later...also I think the circles finds the tangency between the lines...

there is also now the place element along tool discussed here not long ago and you  can decide the number of times or interval to get your perpendicular lines I dont think the lines can ever be perpendicular to both ...

I did it another way years ago for finding the river centre between banks I did it with placing  several circles by two points makes it easier to find the centers for the bspline curve later...also I think the circles finds the tangency between the lines...

there is also now the place element along tool discussed here not long ago and you  can decide the number of times or interval to get your perpendicular lines I dont think the lines can ever be perpendicular to both ...

Lorys--

Thanks for the response.  Placing circles is essentially the same as the straight line method mentioned by George where you're using the diameter center instead.  The more lines/circles you place, the more accurate the centerline would be, so if the computer's able to place its own [infinite number of] lines and run a true (or ideally true) center, then I think that method trumps all others, as shown in Carl's answer.

Carl--

Using the "Untitled" user workspace worked.  I couldn't for some reason snap to the midpoint of the construction line, but putting in an Iso Value of 0.5 is the same thing.  I'll play around with it but you answered my question as to whether or not it's possible.

Thanks to everyone!

I'll have to see (if I'm ambitious enough) where the issue is with that button.

did you find the place element along tool ? this is new or newish ...

The circle method was just easier than lines as you dont have to snap tangent   and force the lines to stop or trim

Not sure if there's a specific "Place Element Along" tool, but there is a "Place Points Along" tool which only places points or cells, and the "Array > Along Path" option which has been available since MicroStation XM.

Thats the right tool ( I should have said place cell not element  along) but it also has place points between elements  and I can  used to use active point or a cell ... but the Celltool.ma from bentley works even better with a cell of say a short line  using center as origin or a small circle..

I have used it to create chainages when dont have inroads as it can place the chainage or stationing ticks at an offset  and at a set interval it will place straight lines cell perpendicular ..

but for this exercise the place point between would be perfect to mark out where to draw the new centre line the quickest possible way.. more points the more accurate