OpenCities Planner now has the ability to render iModel content together with existing project data.
What is an iModel?
An iModel is a distributed relational database holding information about an infrastructure asset. iModels may contain physical and functional models, drawings, specifications, analytical models, etc.
iModels are stored in the iModelHub and can be uploaded using the iTwin Synchronizer tool from your prefered choice of CAD and BIM applications.
For more information about iModel, iModel.js, iModelHub and iTwin Synchronizer visit these links:
iModel – The data format
iModel.js – Open Source software for rendering iModels
iModelHub – Cloud storage platform for iModels
iTwin Synchronizer – Software for synchronizing data to iModels on iModelHub
iModel.js powered rendering
By switching to iModel.js, the project will now support rendering of iModels. However some features, eg. Shadow Analysis, Export 3D and Export Video, are not yet supported in this mode and are therefore disabled. The user can toggle between the two different rendering modes using the Graphics Settings found in the bottom left corner.
Accessing the iModels in the Editor
Find the iModel button in the sidebar. This will open the iModel Manager window. To add an iModel, click the Add configuration button.
This page will list all iTwin Projects that your user has access to. First select a project that will list all the iModels available. Select the iModel you want to load and click Save.
After the configuration has been saved, it will be listed in the iModel Manager. You can now continue to the next section to learn how to add this iModel to the scene.
Coordinate Systems and GeoLocation
If you want to combine the iModel with an exisiting Map Dataset you need to make sure that the project has the same Coodinate System as the Map Dataset you are using. If for example your Map Dataset is defined in EPSG:3857, set this as the project Coordinate System like this:
Then save the project, now the iModel should line up with the Map Dataset.
Configuring the iModel
An iModel consists of a collection of smaller parts called Models, these can be different dgn or rvt files that you added to one iModel (eg. building.dgn or bridge.rvt). A Model is subdivided into individual Categories, all Categories represent levels or layers in your dgn/rvt files (eg. Beam Structure A02). When an iModel is added to the scene, the default behavior is to show all Models and Categories. But this can later be reconfigured if only parts of the iModel are needed.
Configure using an existing Saved View
Usually the iModel has a collection of pre-defined configurations imported from the original CAD/BIM source file. These are stored in the iModel as Saved Views. To load a Saved View, select one from the dropdown menus and then click Load. Once loaded, the Model and Category checkboxes will be set accordingly. If you also want to move the camera to the location defined in the Saved View, use the Visit button.
You can also manually configure exactly what you want to include in this iModel by checking/unchecking the checkboxes under Models and Categories. The iModel in the scene will automatically update when you toggle these settings.
Show Element attributes on click
In iModel On Click setting, you can select an action that will occur when the user clicks an Element of the iModel. A common use case is that we want to list all attributes connected to this Element.
Begin with selecting On Click and then choose Attributes as the action.
Now, when the user clicks on an Element of the iModel, a popup will appear listing all attributes.
If you only want to include or exclude some of the attributes, use the Filter setting.
Limitations in the current release are:
- Only one iModel can be loaded in the scene at once. Multiple iModels can be added to the project but only one can be toggled at one time.
- Only graphics quality modes Low and Medium are available for iModels.
- Features like Export 3D, Export Video and Shadow Analysis are not available for iModels.