The objective of this tutorial is to acquire fundamental knowledge of Grasshopper through a simple definition that employs various functions and components. The intention is to construct an entire bridge starting from a single point, which will be converted into lines, surfaces, volumes, and ultimately, a bridge. Since all the stages are parametric, it allows for endless possibilities to generate countless variations.

Bridge Length

Let’s start with a point set in {0,0,0}

The bridge will need 3 points, one to start, one to end, this will be the length of the bridge, and in between a point to design the curvature of the bridge. This point will be on the line drawn by the two others and will be able to move along the line and in height.

Now let’s create the point on the line

Add a Point on Curve

We have our 3 points.

Bridge height

The middle one will be raised create the arch. Then, a curve is created linking first, raised midpoint and last

Bridge width

The curve is copied horizontally to obtain the bridge width. This is done by moving the curve Y direction.

Add a Loft to create the bridge deck, Nota, the Relay is put to have a better presentation, create a Relay by double clicking on the Wire.

The bridge can have a thickness by extruding the loft surface.

Railings

Let’s first create the vertical bars that hold the handrail

Finish by transforming lines into solid objects. Here, extruded polygons are used, this is one solution among many. For the handrail, it’s also possible to use a Tube which is easier…but creates more polygons.