Why do my properties disappear?
We often get asked why properties that the user added via the Property Set Editor or Automation tool disappears. We are most often asked about this when it comes to properties added on the road and railway features, but it can happen with any data in Quadri when similar situations occur.
For road and railway there are many reasons for this to happen and they all are related to the features in the task getting replaced in some parts of the process. For other tasktypes in Quadri it can happen when there are significant enough change in the data your are adding, compared to what you already had.
Since NP2020 a road/railway/WS task will always try to reuse the features that already exists in the model. You can try this by just rebuilding one of these tasktypes multiple times without doing any changes to it. However, a model that is subject to repeated changes and iterations while finding the best solution will do changes that forces features to both appear and disappear. In this situation we acknowledge that the user can experience the apparent loss of properties on the features. As we will read below, something else is actually happening.
We will continue with a road task as the example.
Properties are "missing"
Example 1:
When the user has added properties from outside the road task (via Property Set Editor or Automation tool) they will not affect future features that are created because of changes in design, when f.ex...
... a new ditch appears with new surfaces...
... a new cut appears because of lowering the model...
... a new pavement object appears because of changes in the input data...
... a change in layer properties gives pavement features with new properties...
... a new road surface appears because of design changes...
... then these newly created features will not automatically inherit properties that similar features already have been given, and thus these have to be added after the new features are created.
Example 2:
Sometimes all/almost all properties that a user added disappears in a rebuild. This can happen when the model goes through a process of building less or no features, before building them all again. This can happen in different situations when f.ex...
... only one cross-section is build in the Cross-section viewer, before all sections are build again
In this situation all the features for this road task disappears. When the model again builds all the features, there are no features or attributes/properties to reuse in the model, and all features are created with a new GUID and the attributes/properties given by the road task conversion rule.
... only a part of the road is build by limiting the from-to chainage, before full length is build again
In this situation a part of the road model is build, and the relevant features of the model, when it was build with a longer length, are reused where that is possible. Afther this partial build, when building the road model in full length, it needs to add new features where there previously was no features, and thus the model has no features or attributes/properties to reuse. These features are created with a new GUID and the attributes/properties given by the road task conversion rule.
For both of these situations in example 2 you will be creating new features, and the situation is similar to what happens in example 1.
This is why features seem to be missing the properties that you previously added to them. They are all new features.
How the Property Set Editor works
The Property Set Editor makes it possible to make a selection of features based on a task and feature selection (via Dynamic Query), and it will in turn list the individual features in a table view where the user can add properties.
Since the features you are presented are the actual individual instances, you are adding the properties to specific features identified with a unique feature GUID. When new features (instances) are created that matches the query of the Property Set Editor, they are added to the table and are available for you to add properties onto them. This is why you often need to add properties on corridor models, as they are often producing new features in different situations.
To get properties on the features you have to add them again by editing the Property Set Editor task and add properties into the tables.
How the Automation tool works
The Automation tool makes it possible to make a selection of features based on a task and feature selection (via Dynamic Query), and it has functionality that makes it possible to add a flow of actions that ultimately adds properties to the features. (Note: Automation tool can also do other things, but that we do not cover in this example.)
When a road/railway/WS task is rebuild and it produces new features (refer to above examples), the user needs to re-run the Automation tool to add the properties to these new features.