Hi all.
I have been working with Inroads SS2 to create a surface (.dtm) file and was looking to create a terrain model from it in Inroads SS4. My surface consists of proposed roadway features (edge of pavement, edge or shoulder, centerline) of the main line as well as existing features for side roads. I'm attempting to build intersections using proposed curves to tie these features together.
I have used Inroads SS4 enough to know that geometry features can be have profiles displayed and adjusted easily. I want to display all of these intersection curves vertically so I can smooth them in between my two crossing features. I know a way to do this with Inroads SS2; however, it would be tedious to create baselines and profiles for all of these features. (Also, I want more experience with SS4.)
Anyway, I used the Terrain Model -> Create from File command and brought in my .dtm that was created with Inroads SS2. This created a bunch of features in the void spaces and other areas that were not originally there. It did capture my features though they are now all on the Default level. Then I tried to use the General Geometry -> Create Civil Rule Feature on the intersection curves and it says the tool is not valid. This basically left me with a "terrain model" I don't know how to manipulate.
I understand how to create geometry within dgn files using Inroads SS4, build profiles, and create corridors; but now am simply trying to take features from a dtm and use them with the new software. Is this a practical application? What exactly is a terrain model and how is it manipulated? I thought they were simply the new name for surfaces (.dtms) but I'm starting to think its more complex than that. I feel like these are just basic questions and my knowledge of the fundamentals is lacking, but I don't know anyone who can explain it to me which is why I am here.
Any help would be appreciated. I'm just trying to learn about SS4 and how a terrain model is built and worked in.
Thanks for reading
-Justin
No, this is not a practical application. While a Terrain Model is a native Element and the equivalent of a DTM, it has many differences.
In Ss2, the DTM contains 3D Features and components. I it loses all of this when converted and simply represents the triangles. However, it is possible to have the 3D linestrings representing breaklines in a file and when these are edited, the Terrain Model will update to reflect the edits. The problem is, the tools for editing the 3D linestrings are not the tools you may have used in Ss2. During the import, there is an option to import the breaklines as 3D elements.
If you want to convert a design - first, you can actually import an IRD. However, there is a dependency issue that can cause the import to fail. You would need to import all alg alignments into Civil Geometry. Next, if you had other non-geometry controls, such as other corridors or Breaklines, extra steps are needed before the import will work.
A big thing about Ss4, is that you generally work in a 2D model and when 3D is needed, a 3D model is created in your file automatically and attached to your file. Then, as you create models, their geometry is modeled in 2D and they are given profiles to define the elevations along the geometry and Open Roads creates the 3D breaklins to represent you model in the 3D model. The only time you should work in a 3D file/model is when bringing in Survey Data.
Your templates can be used, but if you need to also use them in Ss2, you should make copies in case it adds things that Ss2 does not recognize.
Charles (Chuck) Rheault CADD Manager
MDOT State Highway Administration