Creating a Terrain Model from Multiple Corridors

I am attampting to create a terrain model from several corridors.  The location is in an area where several ramps converge and would like to use the terrain model to define the detailed grading that a simple corridor can not produce.

What is the preferred method for something like this?  Is the terrain model even considered the best practice here?

If I import various features from the corridor they come in as a whole entity which is much longer than what I need.  Also, these features can not be modified in any way to trim them to the desired length.

I have thought about making horz. and vert. geometry along the desired features but this seems labor intensive.

Marc

Inroads 674

Parents Reply Children
  • 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?

  • 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.



  • 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

  • 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.

  • 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

    Michael Barkasi

    Application Engineer 

    Reality Modeling