Create a Surface Intersection (point where a ray intersects a surface)

Use the Create Surface Intersection command to create a point on a surface at a given bearing and vertical angle from a specific position (reference point). Specify multiple bearings and vertical angles to create a series of surface intersection points connected by a linestring. This is useful when you need to calculate a daylight line, such as from the top of a pad down to an existing ground surface.

Prerequisites:

Licensed module; See the Subscription Plans page. For a license matrix by command, see the License page in the TBC Community. Also see View and manage licensed features.
Surface

To access the command:

Select Create Surface Intersection in Surfaces > Create.

To create a ‘surface intersection’ point:

In the Name box, pick an object in a graphic view to use its name for the linestring that connects the intersecting points, or type a unique identifier as you want it to appear in the Project Explorer and Selection Explorer. You can also use the name to select the linestring in the Advanced Select command.
Select the layer on which you want the new linestring to reside in the Layer list, or select <<New Layer>> to create a new layer for it.
In the Surface list, select the surface on which to create the intersecting points.
In the Coordinate box, specify the reference point/viewpoint location by picking a point in a graphic view or typing in an X,Y coordinate.
If you typed in a coordinate, enter the Z value/elevation in the Elevation box.
Specify the direction of the ray going from the reference point to the surface by typing a value in the Bearing box or by picking the end of the bearing line. Positive rotation is clockwise and zero is due north.
In the Vertical angle box, specify the angle at which to calculate the ray from the reference point to the surface. Typically, this will be specified as a ratio, such as -2:1.
To create more than one intersection point, check the Multiple checkbox and follow the steps below.
1. In the Number of points box, enter the total number of equidistant points to create between the first bearing and the final bearing.
2. In the Point ID box, enter the starting point name and/or prefix and suffix. Point numbers auto-increment from the specified point ID. For example, if you enter “Pt 11 x”, subsequent points will be named “Pt 12 x”, “Pt 13 x”, etc.
3. In the Final bearing box, specify the direction of the last ray going from the reference point to the surface.
4. In the Final vertical angle box, specify the angle at which to calculate the last ray from the reference point to the surface.
By default, intersection points are calculated counter-clockwise from the first bearing to the last. To reverse this order, check the Clockwise box.
The default counter-clockwise and checkbox option enable you to create points for either the small (1 below) or large (2) arc from a 360º range.
Select an option in the Linestring defined by group:
- Coordinate - Select this to create the linestring using the calculated coordinates at each node without creating point objects.
- Point ID - Select this to base the line segment end points on named point objects, meaning that if you move one of the points, the linesting's geometry will update.
Click Apply to create a point object where the ray intersects the surface.

Dependencies:

If you use the Point ID option, the linestring is dependent upon the point objects used to create it; if the point locations change, the linestring's geometry is updated accordingly.