Grill like a photo

can someone give me a clue on how to do this on Rhino 5?

What type of a grill?

Sorry I forgot to attach the image on my previous post, now it’s attached.

No photo

Duplicate thread !!!

Thank you so much.
Marcel

in the expression: v*r (inverted v) 2/1, how to you do the inverted v?
Can’t find it anywhere?
CHeers

I think it’s better to ask the same question in the other thread.
This duplicate thread makes things complicated.

It is simple math to.invert something relative to a circle of radius r centered on 0. V is a vector and l the length from center to 0.