Hello,
As the title said I’m looking to make a loop of planes (along a cylinder if that matters) flat along the z axis. A Google search termed up nothing, any ideas?
Scale to zero along whatever is the appropriate axis. Hard to say if that’s what you want without seeing what you’re working on, but it’s a standard method of aligining, and in the process flattening, a set of vertices. Use keyboard inputs for both the constraint axis and the scale vale, e.g. S-KEY (scale), Z (z-axis), 0 (zero on the numpad) – it’s faster & more accurate than using the Scale widget.
You can also set the coordinate system to normal if you want to flatten along the averaged normal, or create a new orientation with ctrl-alt-space to flatten along an arbitrarily defined normal.