Ridge Lines

Ridge Line objects control the slope direction of surface triangles for the purpose of drainage. All triangles in the zone will try to slope away from the closest Ridge Line unless overridden by the slope of an aligned surface zone.

Ridge Lines must be open geometry and not form a closed loop.

When planning ridge lines, it is important to understand how they work in the optimization process. In the following simplified example, any triangle with a centroid that is above or below an end point of the ridge line will slope away from the point.

Any triangles with centroids that are not above or below end points the line, will incline away from the ridge line perpendicularly.

In this example, the intent of the grading looks something like this.

Using the Wireframe theme and Hydrology Direction Vectors in the Visualization Toolbar, you can better see how Grading Optimization will attempt to solve the surface grading for ridge lines.