This Grasshopper definition uses a grid of points to generate a series of curves that respond to an attractor point. This definition is a great example of using really simple and basic concepts of parametrics to accomplish a more complicated goal. Essentially, all this definition is composed of is an attractor point that adjusts the curvature of a plane and an attractor point that adjusts the radius of circles that are projected onto that surface. The small bit of vbscript at the end is used to split the circles from the surface.
Note:Version of Grasshopper Needed-(Grasshopper 0.6.0019)
a = rhutil.RhinoSplitBrepFace(y, 0, x.ToArray, doc.AbsoluteTolerance)
As a bit of code, its actually not very necessary. Does it really matter if you split the circles in grasshopper or rhino space? In this case, not really, however its useful to know and more importantly it brings up the question of how integrated grasshopper can become with rhino. As a tool, grasshopper can be great a modeling things really quickly and when you start to make relationships its really great at doing calculations for you. These panels are a good example, they illustrate both a much easier way of modeling and an easier way of calculating the relationships between points. Grasshopper presents a much clearer way for the designer to understand what the relationships are within a given project. Given this diagrammatic way of seeing the logic behind an object, designers should begin to spend more time articulating these relationships and less time articulating the form.
The set of images at the top of the article represent an ethereal form of an object. They show a logic, but in order for them to mean anything they need to be put within context. The context would then generate a meaningful form. Whether you design in grasshopper or rhino space is irrelevant as long as there is some context attached to the object. An example with respect to this tutorial could be assigning the attractor points some sort of value, such as amount of light, pre-existing site constraints, or even something as simple as compositional logic.