The Sandcastle Annotation process can be broken down into 4 main steps:
- Create labels describing object types
- Outline a facade in the map
- Assign the facade pre-made tags
- Link associated facades together (optional)
Though these steps are generally followed in order, given the fluidity of our process at times we would go back a few steps to add in tools or tags to be used later. Annotation was performed at the facade level, with each facade of an object being individually outlined and given labels.
To begin, we create labels describing the characteristics we want to assign to the facades we will be annotating. These are made before entering the map, though the label maker should know the general map components before they begin creating their labels. Labels can be further broken down into two components: classes and tags. Classes are the first level of labels, which describe the basic facade or object type. Examples of these include "fortress part," "house part," "people," and "roads and paths." Classes are typically selected before annotating an object once on-map annotation has begun. Once a class has been created, it can then be assigned sub-labels known as tags. Tags are the second level of labels, which describe the characteristics of an object. Using the fortress part class as an example, associated tags included "fortress part type," "facade or plane orientation," "buttressed," and "tower shape." When in the map, after selecting a class and outlining an object, the tags will then appear as options to select in the sidebar. While an object must be assigned a class, it does not need to be assigned any tags, and not all tags listed in a class apply to all facades. For example, a fortress may have a tower but no buttresses, in which case the "buttress" tag would not be selected.
In summary, the first step is to create classes that describe a basic facade/object, and then tags that describe the characteristics of said facade/object, some but not all of which may apply to every specific object but apply to the general class.
Once labels describing the facades have been created, the facades can be outlined. This step involves first selecting the class the facade belongs to, and then simply tracing around the edges of a facade, capturing the image within. In Supervise.ly, this is typically done by using the "Add bitmap" tool, placing a single point within the facade using the "brush" tool before moving to the "Polygon Fill" tool to complete the outline. Classes are assigned specific colors, so the outlines facade will gain a translucent overlay of whatever its respective class' color is. Once the outline has been completed, the checkmark in Supervise.ly's top bar can be pressed, populating the side bar with various tags assigned to the class.
Assigning Facades Tags
Once a facade has been outlined, tags belonging to the class the facade has been assigned will appear in the sidebar. Whichever tags apply to the facade can then be selected, tags that may apply to the class but not the exact facade that has been traced being left unselected. This assigns certain attributed to that facade, which can be exited out of by reselecting the checkmark in the top bar. No other steps need to be taken, and at this point base annotation is complete. If the outlined facade is reselected, all tags will appear.
Linking Associated Facades
If several facades belong to the same object, they should be linked together. An example of this would be the three house parts - facade (wall), facade (wall), and roof - making up a single house. By linking facades, they are grouped into what a computer can recognize as a single connected object. This is done by selecting the "link with other object" icon listed next to one of the objects needed to be linked, which will open up a menu of other objects (in our case, facades) that the facade can be linked to. For objects consisting of three or more facades, all facades should be linked to a single main facade. If a facade is not part of an object with multiple facades, this step is not necessary.