Question:

What are the Terrain Model Rules in OpenRoads Designer

Answer:

Terrain Models created using the OpenRoads Designer tools have an additional level of intelligence called rules that preserve a link between the source data and the terrain model so that it can be updated when revisions are made to the source data. This has very powerful implications for how terrain models are updated and edited. For example, terrain models created from design elements are automatically updated as changes are made when geometry and templates change. Unlike the past when DTMs and TINs were a result of a design process, terrain models are a dynamic representation of the current source data.

Sometimes it is desirable to lock or remove the rules to temporarily or permanently deactivate them. For example, there are tools to make minor edits to terrain models that may be necessary if the source data no longer exists or is impractical to edit. Also, large terrain models and terrain models shared with non-OpenRoads users may benefit from removing the rules. The Lock, Unlock, and Remove Rules tools are used to change how terrain model rules are applied.

Deactivate Rule (Lock)

 Temporarily deactivate rules.

 When deactivated (locked), terrain models will not automatically update when the source data changes.

 The Edit Terrain Model tools require the terrain model to be deactivated (locked).

Activate Rule (Unlock)

 Activates rules. This is the default state of a terrain model when it is created.

 Edits to source data are updated in the terrain model either automatically or using the Update from Source tool.

 If previous edits were made with the Edit Terrain Model tools they will be lost if the terrain model is set to activate rules (unlocked) and the rules are reapplied (model re-triangulated). The edits are saved if the terrain model is just set to activate rules (unlocked).

Remove Rule

 Permanently removes rules. Once removed, rules cannot be reactivated, the link to the source is broken permanently.

 Improves the performance of a terrain model and is recommended for all large terrain models.

 Recommended when sharing a terrain model with non-OpenRoads/OpenRail Designer users such as MicroStation, plant, or building.

Note: Terrain Models created from Survey field books have a slightly different locking process. Instead of locking the terrain you need to

deactivate the survey processing rules. To do this, go to the Survey tab in the Project Explorer. Right-click on the survey project and select

Deactivate Survey Processing Rules.