Mesh Difference & Circle Location

Hi, I am new to gh and Rhino and trying to build a structure with tubes inside, maybe like a lotus root. There are two problems I want to consult:

(1) Mesh difference

I have built some tubes as lofts and then a cylinder around the lofts. I turn the cylinder and the lofts into meshes and want to subtract the lofts from the cylinder with ‘Mesh Difference’ but it gives the result above. I wonder if I should actually turn the lofts’ centres into holes before turning them into meshes.

What functions should I use to achieve this?

(2) Circle location

I want to set the base circle of the cylinder to be around the populate 2D points. I draw the circle based on the same rectangle for populate 2D, but the location is different from that of the rectangle.

How can I set the circle right without drawing the circle on rhino? (16.4 KB)

This is the gh file I have. Any help / suggestions appreciated. Thank you!


Is there any specific reason why want to use meshes?
Doing this with breps (polysurfaces) and solid difference is way easier.

If you still need a mesh, you can use the QRemesh (Quad Remesh) component from Rhino 7. (16.6 KB)


Thank you so much, diff-arch! This is exactly what I want! And the gh file is so nicely organised . . .!

I used mesh just because I am still unsure about the differences between mesh and brep even after some search. The math part of calculating the location is definitely the hardest part for me :woozy_face:

It calculates the diagonal of the rectangle from its width x and height y. The width and height can be viewed as opposed and adjacent sides of a right triangle. In this scenario, the hypotenuse h is the third side and diagonal of the rectangle. The formula I use is called Pythagorean theorem and goes as follows: h^2 = x^2 + y^2

The diagonal can then be halved and used as the circle radius. You thus get a circle that - when drawn from the center of the rectangle -, is enclosing the rectangle and thus the random points that you generated inside of it.

crystal clear, thank you :pray: