addCells in Envimet Grid component

In the Envimet Grid component there are the four “addCells”, and they are set as Default to 2. In my model they add 2 grids in the lower and the left side and 3 in the upper and in the right side. If I set these values to zero, it adds the same grids anyway.

Is there a way to add ZERO cells?

Thank you!

…anyone can help please?

This is probably question that is best answered by @AntonelloDiNunzio as he authored the Envi-met components.

Thank you very much @chris. I’ll be waiting for @AntonelloDiNunzio then.


Hi @Marcello,

Sorry for my late reply. the border cells cannot be less than 2 for now because of the method that it uses to calculate the sparse matrix algorithm. Could you tell me what is your goal so I can see if I can help you in some way?

A useful info:
A rule of thumb says the distance between buildings and the border has to be about 1/2 (or better 3/4) of the height of the highest building.


Hi @AntonelloDiNunzio
Thank you for your reply.

My goal is to reduce the time of calculation, as I need to run 840 simulations.
In my models I always remained in the safe side, calculating 1/1 of the height of the buildings as distance from the border.
I attach here my file. (414.9 KB)

As you can see, the main grid is 2 cells wider than the soil in the lower and left side and 3 cells wider (why 3?) on the upper and right side.
I might reduce the dimensions of the soil, as I am interested only in what happens inside the canyon between the two buildings, but then the bulding on the right would be partially outside the soil…and it could be a problem, right?

Thank you for your time. Don’t worry, you were not late…considering that you are doing it on a volountary base!


Hi @Marcello,

I understand the reason now, 840 simulations are so many with envimet.
I think you can use a simple 2.5D modeling instead of the complex 3D modeling of envimet. I share a definition that lets you create all your small models accurately, I use another plugin based on the dragonfly envimet components, but I would like to bring the same principle of the grid to dragonfly-legacy as well.
Instruction and plugin here: (Remember to unlock the zip file)

After that, I think you can continue with Dragonfly envimet components to set simulation files and iterations. (436.9 KB)


Thank you @AntonelloDiNunzio for this plug-in.
I am using it to set all my inx files.

I encounter an error when I set the receptors.
When I connect the inx Grid to the Receptor component, I get this error message: “Runtime error (ArgumentTypeException) : expected Vector, got Point3d”
What am I doing wrong?

I attach the Grasshopper file. (454.6 KB)

Thank you a lot!

Hi @Marcello,

you should set the workflow in this way:

because it is not dragonfly legacy - to respect the regulation of the forum - you can write me some emails if you have other specific questions about this project.