How can I make a surface based on another surface in grasshopper?

Hey Guys,

I want to run multi-objective optimization using ladybug and etc. I am having trouble setting up my model. I have a basic room of 3x4 m with 3 m of height. I need the glazing of the south-facing wall to be a percentage of the floor area (horizontal surface) but I don’t know how to do it. Furthermore, the south-facing wall needs to be two separate surfaces (glazing and wall) so that I can assign different reflection and refractive coefficients to them.

I really appreciate it if you could help me; I am new to the grasshopper.

Thank you all in (10.8 KB)

It seems that your question is more related to Ladybug than Grasshopper:

@Mahdiyar Thank you but I already asked the question there and it was apparently related to python and grasshopper. I have got the feedback that I need to use geometrical definitions in Grasshopper but I don’t know how!

Hi -

I don’t see any reference to python in that thread…

At any rate, you could probably do something like the attached to create a rectangle for the window in the south wall. I’m sure you will have to take further steps to get that back into Ladybug. (19.0 KB)

@wim Thank you very much. I thought creating that constant thing is in grasshopper :smiley:

Thank you very very very much for the file; that’s exactly what we needed :pray: :pray: :pray:. I created the surfaces from what you created. One for glazing and one for the wall. There is just small trouble that I am having; when the rectangle of the middle surpasses the boundaries of the walls (based on the ratio), the glazing and the wall, overlap (outside of the rectangle). I guess it is working fine as long as everything is within the wall boundaries. Also, I would really appreciate it if you could give us your feedback on what we created based on your file.

Also, I was thinking is there a way that we avoid the window rectangle (based on ratio) never goes out of the wall boundaries?

I really appreciate your help and time.

Edit1 - (17.3 KB)

The easiest way is to just limit the vertical height of the window to always be less than the height of the wall - as in the attached example.
The problem is that (1) for the solution to be usable by Ladybug/Honeybee, there always has to be a gap between the window and the edges of the wall, and (2) if you then allow the ratio to become 100%, you will be in trouble. And that is just for the case where the floor area equals the wall area. If the floor area were to be larger than the wall area, you would have to limit the max ratio even more.
A lot will depend on which variable is within your control …
Edit1 - (20.5 KB)

@wim Thank you very very much for your help.