How it was done:

The curtain panel pattern family used for the divided surface on the building mass contained a material instance parameter for the glass middle section. This allows the panel material to differ within the building mass family.

The dynamo program was then created so that a form element could be selected and a list would be outputted. This list is in a tree form, but can also be envisioned as a matrix of the window panels. The idea of the matrix is important because how the matrix is read by dynamo will determine what needs to be done in order to create the desired material pattern applied to the curtain panels.

Understanding how Dynamo is reading the lists (knowing what order the window panels are placed in the list) was personally the most difficult part of this project. Imagining the lists more like matricies helped me better understand.

Dynamo Program

Brief list of instructions on how to use the Dynamo program:

It must be noted that these instructions should get the user started. It takes a little bit of testing and adjusting in order to accomplish what is wanted.

1.  Select form that has the divided surface you want to edit
2. Create new materials with desired properties and insert the name of them into the string nodes associated with the value input on the Set Element Parameter node
3. Be sure to input the proper parameter name from the curtain panel family into the string node for the parameter input on the Set Element Parameter node 
4. The number input on the Repeater node takes user judgment depending on what pattern is desired. 
5. The element input on the Set Element Parameter node also takes user judgment. Look at the watch nodes to decipher how the program is reading the window panel matrix.