the receiver is connected with another piece of my definizion which defines how the component's arches open. It is a parameter, for me.
You can see this part here:
Well, the first receiver (top left) is connected with the list which contains the centroids of every triangle of my mesh (my canopy, that I turned into a series of triangular surfaces). In this part of the definition I evaluate the Z coordinates (extracted form the points).
I execute some operations in order to have my values from 0 to 1 (parametrization). Then I sutracted the lower value of the list to all the data. So I obtained a new list of numbers, which stay from 0 to 1 and I can use in order to determine a gradient in the arch openings.
The result? If you look carefully to the rendering I posted you'll see that the arches are less opened near the ground and more opened near the top. It's a structural way of design the canopy. The more loads you must support, the more closed your arches will be (and the more stronger you should be).
Anyway consider this part as not important, because this parameter is just a my interpretation, it's not essential in order to obtain the canopy I posted. If you want you can just substitute that emitter with a simple number, from 0 to 1. Don't know, try to put 0.4 as an imput and let's see what happens. The result will be more similar. ;-)