This part will introduce the capability of modeling the existing project site (terrain model). For that workflow you can use two different alternatives:
- All major design packages can export your terrain model into LandXML file (open data format). You can use that as a reference for a current/proposed surface inside Explorer.
- If you are looking a way to include an orthophoto to you terrain surface, you can use Modeler workflow (inside AutoCAD Civil 3D). This section describes the procedure in more detail.
Tutorial file location (folder)
From the folder you can see the sub-folder structure that is explained below:
- LandXML - From here you find various LandXML files that represents various parts of the terrain. Those can be exported from different design packages, wherever it has been originally designed. We use those files later for references purposes, but you can also use those for giving a project site information to VDC project. You typically do not use same information twice. Meaning that in your final VDC model you have your design only through one format.
- VM - *.vm file format is used for Modeler generations. In that way you can convert 2D data to 3D or deploy native AutoCAD / AutoCAD Civil 3D objects into *.vm format. From this folder you will also find a *.dwg file as well as already generated *.vm file. They both share the same name. To generate a *.vm file you also need a definition file that is saved with an *.ini extension. If you want to include an orthophoto onto terrain surface, you use Modeler workflow.
Because we want to map an orthophoto onto terrain surface, we concentrate on the sub-folder VM. From there you find three *.dwg files:
You start from that *.dwg file. You also find special definition files with an *.ini extension that are automatically opened when you use Modeler tools inside AutoCAD Civil 3D. You also have completed versions in *.vm formats that can be directly used inside Explorer. All those three different *.dwg files represent different terrain surfaces:
- Context_Orthophoto.dwg - wider area of the project site (does not include the project area itself, where the reconstruction will be carried out).
- ProjectArea_Orthophoto.dwg - project area where the major construction work will be carried out.
- ProjectArea_Orthophoto_CorridorCut.dwg - later in the workflow you may also want to have a more specific project area, where you have removed only that part of the project site surface that is cut by road corridor models.
Step-by-step guidelines to create project site area with orthophoto
Open drawing Context_Orthophoto.dwg inside AutoCAD Civil 3D. You should see a similar picture:
Using AutoCAD ribbon tab, go to Modeler tab and click on Rules. Modeler main toolbar opens:
Modeler toolbar is the place where you create different rules that are applied to AutoCAD objects. All defined rules are kept in a separate file with an *.ini extension. Although it is possible to have only one *.ini file throughout your whole VDC project, where you define each and every rule that you want to use in separate drawing, in this tutorial we use the second method - we have separate *.ini file for each and every *.dwg file that we gonna use for generating data for VDC model. Using the latter method, please ensure that *.ini file is with the same name as your *.dwg file, then it will be selected automatically when you open up Modeler tools in your active *.dwg drawing session. Because with the current tutorial the proper *.ini file is already created, it will be automatically used. All rules are defined and we take a quick look to those rules that are important for each sub-task.
Next to each node, you will see a "+" icon if it holds some rules. And vice-versa, you can click on "-" icon, if you want to close that node. Also please note that in some nodes (ex Materials) you may have several rules. But those that are applied to current drawing are in bold. That feature is controlled through a menu: View > Gray Non-Existing Items.
We will first include surface (terrain) data into our VDC sub-model. Because the surface is modeled inside AutoCAD Civil 3D, we use Civil3D node to include that data. Just double click on Civil3D node, or in our case you can also check the already made rule called: Context_Orthophoto.
Typical workflow inside Civil3d dialog is:
- Add a Main group. This is for a healthy project structure. In our tutorial we use several sub-groups (separated by "/").
- Select objects (object groups) that you want to pick from AutoCAD Civil 3D drawing. Just click on a respective row, box Selected.
- Group is automatically filled in, based on AutoCAD Civil 3D object name.
- Material is not needed here, because we plan to use an image on a surface element.
- Cut Mode is only used, if you want to cut into some other surface.
- Type is read-only parameter, that helps to differentiate in between of various AutoCAD Civil 3D objects that you may have.
Once you have read (filled-in) all the parameters. Click OK. We need to generate a layer for our material (orthophoto image) that is used inside Material Area node. This is only needed if you use some references (like LandXML, AutoCAD Civil 3D objects that you want to map with a material, etc.).
Note: Modeler is using layer-based (or object-based) rule mapping.
Although it generates a *.vm file to the same location as your *.dwg file, it is not yet ready to be used inside our final VDC model. Because it is not correctly mapped (or the mapping is not checked). During this generation, one new layer was added (because we use one AutoCAD Civil 3D rule). The new layer is always generated as long as you change the group or content (in our case, surface) name. Therefore it is good if you always clean-up those layers, that you do not need. Because this layer is not a real layer (no AutoCAD objects are on that), please be careful when you use AutoCAD Purge command. This will remove those layers as well. Still, Purge command is the easiest way to clean up your drawing.
Open up (double-click) a first rule under Material areas node.
Pay attention to special settings in this dialog:
- layer - this a layer name, where you 2D polyline is placed (that represents the area, to where to apply an image). You can double-click on layer area to reselect that layer.
- materials - this a material that holds an image of your orthophoto. If you double click on it, it will show a separate dialog where you can also create new materials. Pay attention that all materials are selectable and changed also under Materials node.
- description - this can be used to shorten the name that is visible in Modeler main toolpalette. Not a required parameter. In this example the same name is used, as for layer parameter.
- info text - additional description, text that you may want to include that is available in the model.
Note that the material refers to a certain image file that can be found from a project Textures folder. If you click on Material Properties, you can see material's special parameters, including filename, defaultwidth and defaultheight.
Those parameters are used to define the image file and the area width/height. Close the dialog. And close also Select Value dialog. You are now back in the main Material areas dialog.
You also need to pay attention to the following parameters:
- automatic_texcoords - select yes, so that coordinates will be automatically selected based on 2D polyline.
- target layer - select a layer that was generated for your AutoCAD Civil 3D surface. This will be used to map an image only to the surface area.
- group - select a group for your sub-model, we use the same group here as inside Civil3d node to keep everything well organized.
Note: Groups are automatically generated/added when you write those into group field in Change Setting dialog (remember to add a "/" for a subgroup). Alternatively you can create groups through a menu: Model > Groups...
It will open up a separate dialog where you can see a group selection tree. Although some prefer to include all group levels into each and every *.ini file, please be aware that even if you have not mapped any object onto that subgroup, it will be still included into your *.vm file. Of course it is an empty node there, but sometimes it makes it difficult to find objects that you need, if you have loads of empty group nodes.
Click OK to close the Change Setting dialog. You are now ready to generate your terrain sub-model with an aerial mapping. Click on a button: Generate and View Model.
This will regenerate your model (as you did before) and also opens up a Explorer as a viewer package for your *.vm file. Please also note that your *.vm file is automatically placed to the location where your *.dwg resides. Your sub-model should look like similar to the following image:
Note: You should see a surface onto where a selected material was mapped. If the surface had holes in it, those are also not mapped with an image. Please also note that on the left hand side you see a group level. In final VDC model, it is important that your follow common rules when including different sub-models into various sub-groups.
After checking you terrain sub-model, you can close the Explorer window. Later you can open those *.vm files directly with Explorer and you do not need to follow Modelerworkflow again. Of course, when the design changes, then you recreate the *.vm file.
As you have successfully generated a terrain sub-model, it is also good to save your Modeler *.ini file. For that, just select from the menu: File > Save Configuration...
You can re-select the location and name for your *.ini file, but in this tutorial it is recommended that you always keep the same name for your *.ini file as you have named your *.dwg. And also ensure, that both files (*.ini and *.dwg) are saved to the same location. You can close the Modeler dialog. It will warn you, if you want to save your settings. Because you just did it, you can simply dismiss that warning. Click No (or Yes, if you think that you need to re-save your settings).
Close the AutoCAD drawing file.
Because other two *.dwg files share the same procedures as the currently shown, you can practice those on your own. If you open those *.dwg files, and after that also Modeler dialog, you will see that new settings file (*.ini file) will be loaded that holds all needed rules for that specific *.dwg. Repeat the process and in the end you should have three different *.vm files from this section that you will use in the final VDC model.
Note: When you work with Modeler and save your *.ini files, system automatically creates a backup version of the previous file. Sometimes it is good to think that you have some previous definition files still available. In this tutorial we have not kept those *.bak files as well as no separate backup folders. If something goes wrong, you can extract (copy) needed definition and drawing files into your current working folder and start again. Therefore, in a clean system (with no definition and drawing backups) you folder may look like this: