Apply 3D by Slope to Target

The Apply 3D by Slope to Target from the 3D Geometry Tab in the Civil Ribbon Tab is very useful to adjust Terrain models near the bridge abutments. Users can rearrange the terrain slope to match a reference and create models adjusted to reality.

Though, it is indeed a general tool used to create a tridimensional element from a line to a surface and, as a Civil Tool, originally created for expanding the Alignment to create the Corridor modeling surface, despite it might be a very simple and straightforward task for those used with these road features, for bridge engineers just starting to expand their activities to the 3D Terrain modeling it might get tricky to learn it without more detailed explanations. Therefore, this Wiki article is intended to guide users into the best practices to allow them to start learning the Apply 3D by Slope to Target tool by experimenting just doing it.

To model an abutment slope to a terrain model in OpenBridge Modeler users could follow the steps below: 

1. Isolate the necessary elements for your visual reference, preferably in a 3D View. Use the Explorer Window to turn off all bridge elements, but not the abutments. Also, turn on the terrain model, by selecting it and modifying the Properties. 

2. Create an additional reference line from where the 3D slope will target the Terrain: In View, Select Wireframe, then in the Workflow the Drawing option, as shown below. Assign it to the Model and the Level Terrain_Design. At the Ribbon: in the Home Tab at Placement select a Place a SmartLine to draw the line from where the new terrain slope will intersect the abutments. Consider this line as the starting point or the limit until where the Terrain will be modified. As you don't want to change the Terrain of the Corridor just behind the abutment you might want to include the wing walls in the line. In most cases, it is easier to draw the line at the wing walls and the abutment, and then as a second step, just move this line slightly back to the other abutment face, as shown below.

3. Use Apply 3D by Slope to Target icon from the Civil Tab Ribbon, at the 3D Geometry Tab, using a Plan View and a Profile Model. Set the Parameters by texting or clicking:

1. Slope Option: To Terrain Model
2. Cut Fill Option: Cut And Fill
3. Start/End Cut/Fill Slope: The slope percentage from the line entered as a unit value: for example, 0.5 = 50%
4. Corner Option: Rounded
5. Transition Type: Constant. Only used if the Start and End values are different.
6. Slope Location: Consider the Smartline creation, the line Start, direction, and End.
   1. Side: Consider the Smartline direction to set the Right and Left sides as in the picture below.
   2. Start/End: Either Lock to Start and End or enter this when with values or data points. The reference is the actual length of the Smartline.
7. Feature Definition: Terrain Model. Set the Feature Definition to a Terrain feature to get the correct symbology.

Prompt sequence: Datapoint, SmartLine, Reference Terrain, Datapoints until it accepts. Note that for an available set of data it will start drawing the start and end perpendicular line as a dotted line in orange, and then the new terrain borderlines in blue, as shown below.

4. Additionally, users can then Create the Terrain and apply it to the Terrain mesh: Turn off Terrain Reference for easier visualization, and at the Civil Ribbon Tab, at the Terrain Model Tab, use Create Terrain by Elements Select the two Boundaries. Data click walk thru all Parameters to Accept. At the Civil Ribbon Tab, at the Terrain Model Tab, use Edit Terrain Model to Merge the new component into the existing terrain. 

More useful links:

OBM/ORD Online Help:

3D Geometry 3D Tools (bentley.com)

Apply 3D by Slope to Target (bentley.com)

Additional 3D by Plan Profile (bentley.com)

Create 3D by Slope to Target (bentley.com)

Open Profile Model (bentley.com)

Video of the same feature in use at ORD (from the alignment):