Creating a Terrain Model from Multiple Corridors

RE: Creating a Terrain Model from Multiple Corridors

Tsholofelo Oageng — Wed, 12 Jul 2023 11:28:20 GMT

Hi Kaitlyn,

Did you come right with this?

Chuck Lawson

Bentley Civil Road , please may I get some assistance. I have included an image as reference.

I have attempted top meshes, bottom meshes, appending and merging complex terrains.

However the terrain creation tool removes either the bottom or the top mesh.

My Regards

RE: Creating a Terrain Model from Multiple Corridors

Kaitlyn Clark — Tue, 01 Oct 2019 14:35:23 GMT

Hi Marc. Did you ever get a good workflow established for this? I'm in a similar dilemma and trying to figure out the best approach.

RE: Creating a Terrain Model from Multiple Corridors

Mike Barkasi — Sat, 16 Aug 2014 15:34:15 GMT

Hi Marc

If I understand you :

1. there are multiple corridors coming together at an exchange

2. you need to create a top surface of a limited area including several corridors at the exchange area

3. your concerned about the integrity of the terrain due to overlapping features from multiple corridors.

I believe Mark and Adam have the answer when combined. The process would look like this :

1. create a new 3d dgn

2. attach the corridors used in the exchange (3d model)

3. turn off the component display through level manager or project manager in the original files

4.create individual terrains (we will borrow site modeler terminology here and call these objects) from each corridor by selecting the key breakline features i.e. CL, EoP, ToC, BoC etc.

5. Concerning overlapping features- it is a general practice when creating intersections or target alias of corridors to use corridor clippling. this process clips one corridor based on the boundary of another corridor (or terrain) - when a corridor is clipped the 2D entity of the clipped corridor feature remains, however the 3D corridor features will clip. since we are referencing the 3d features you will only be triangulating the features as displayed

6. create a complex terrain, select a main corridor object and add the secondary objects , using the merge function (note to use merge they all must intersect the main object - another option might be to use the existing ground as the main terrain..

7. last draw a 2D element (shape) and create a clipped terrain from the complex....the boundary can be made to fit as close as needed and the resulting clip terrain should update if any aspect of any of the corridor models or boundary is modified...

HTH Mike B

RE: Creating a Terrain Model from Multiple Corridors

Chuck Lawson — Fri, 15 Aug 2014 11:49:21 GMT

I am not sure if this will achieve what you are looking for or not but worth mentioning. If you change the project settings for each corridor to output a "top mesh", then you can make one terrain model where all top meshes would be included. There is also a mesh tool in MicroStation where the boundary of each mesh could be extracted. I have created a video on this topic you might take a peak at.

The link will be good for about a week. With the mesh boundary extraction, you would have to make one for each mesh and work with it accordingly.

ftp.bentley.com/.../CreatingTerrainModel.zip

Chuck

RE: Creating a Terrain Model from Multiple Corridors

Marc Bachand — Thu, 14 Aug 2014 10:40:34 GMT

That is not the issue at hand in this particular situation.

I have several corridors which are part of an interchange. In many areas, the infield areas, there are some portions of the corridor that I want to maintain and others that should be removed. Basically to complete the grading in these areas.

I know I could import the graphics but that breaks the link back to the corridor. If you simply import to corridor lines, it will work, but in most cases those lines extend far beyond the limits of the infield area in question.

I am wondering what the recomended workflow would be for an area like this? From my investigations it does not appear to be possible without breaking the linkage back to the corridor. Therefore, I think this type of work should be done late in the design process, when most of the corridors have been already set.

RE: Creating a Terrain Model from Multiple Corridors

Adam Wieczorek — Thu, 14 Aug 2014 04:06:43 GMT

Try to create separate terrain model from each corridor and then create complex terrain model.

RE: Creating a Terrain Model from Multiple Corridors

Marc Bachand — Wed, 13 Aug 2014 23:24:17 GMT

I assume from the lack of other responses that there is no good way to accomplish this? The method referenced above does not work with 3d features from the corridor. Furthermore, when these features are added to a terrain model it triangulates to the limits of the feature, which most of the time extends far beyond the limits of the required terrain model.

It seems that the only way to accomplish this, until improvements to the software are released, is to copy the graphics from the corridor, breaking the linkage to the corridor, and importing those graphics.

RE: Creating a Terrain Model from Multiple Corridors

Marc Bachand — Tue, 12 Aug 2014 11:24:14 GMT

The problem is in creating that boundary element in the first place. Some of the elements can extend far beyond the area where the terrain model is required and some still can cross each other at some point due to the nature of the interchange. Having to trace over the elements is not the answer since a change in ramp alignment would require a manual edit of the element.

To me, the best approach here would be to allow the editing of a terrain model element similar to to geometry behaves. An element could be added to the terrain. It could then be partially deleted creating an "interval" similar to the geometry workflow. In this way the element still maintains the linkage to the original element but the limits are as shown graphically.

Marc

RE: Creating a Terrain Model from Multiple Corridors

Mark Marnell — Mon, 11 Aug 2014 12:46:59 GMT

The boundary element could be just a graphical shape that defines the area - if the original terrain has a feature set to 'Boundary' (to prevent the slivers forming) the clipped terrain will respect that setting, with no slivers being created.

RE: Creating a Terrain Model from Multiple Corridors

Marc Bachand — Mon, 11 Aug 2014 11:32:44 GMT

I suppose that would be a solution. Although, it does present several other challenges, namely:

How is the boundary element defined?
What stops the sliver triangles from forming in the clipped terrain model like it does in the full TM?

RE: Creating a Terrain Model from Multiple Corridors

Mark Marnell — Thu, 07 Aug 2014 15:01:24 GMT

Could you not create a terrain from the original elements, which are too long, and then - from the resultant terrain - just create a clipped terrain? That would probably be quicker than creating the offset features, I would say.

RE: Creating a Terrain Model from Multiple Corridors

Marc Bachand — Thu, 07 Aug 2014 13:42:38 GMT

I have add good success doing the following:

Create an offset horizontal feature (offset=0) along the corridor template geometry line over the portion you want to include in the TM.
Create a project profile also using the template geometry line.
- I noticed that if the TG line includes gaps that the TM does not include it for whatever reason. If you have this situation just add vertical geometry snapping to the offset lines
Import these feature as terrain model boundary elements

Hope this helps someone.

Marc