topic Re: Can someone explain how to understand Cutplane with thre in Libraries & objects

Can someone explain how to understand Cutplane with three ar

Anonymous — Mon, 31 Jan 2011 14:42:45 GMT

I've been struggeling lately to understand cutplane with three arguments.
I really can't understand where the cutplane is drawn so it would contain all three arguments.
I had a hypotesis, and I drew a plan in an coordinate system that had
4 corners. It was coordinates to 1.corner: argumentX,0,0, coordinates to 2.corner: 0, argumentY,0, and then I made a paralellogram that connected these corners to two points on a paralell line to the line between the two first corners in the xy-plane, but placed at the height that the argumentZ defined.
But when I tried to use this "new knowlede", I figured out my hypotesis must be wrong.

Re: Can someone explain how to understand Cutplane with thre

Anonymous — Mon, 31 Jan 2011 15:13:43 GMT

What I really want to do, that is the background for my struggles, is to have a possibilyty to use a cutplane that cuts through the XZ-plane with 90 degrees, and through the YZ-plane at an arbitrary angle.

Re: Can someone explain how to understand Cutplane with thre

Anonymous — Mon, 31 Jan 2011 15:24:54 GMT

Hi Anne,

it hase to work as in the image. (I hope it)

Best Regards,

Re: Can someone explain how to understand Cutplane with thre

Anonymous — Mon, 31 Jan 2011 15:46:41 GMT

I think you (and I) are absolutely right. Now I went back to the original object I wanted to cut, and thought more easily an practical about it, and suddenly I understood.
Sometimes "I'm lost in space".

Re: Can someone explain how to understand Cutplane with thre

Anonymous — Fri, 04 Mar 2011 04:27:26 GMT

I don't see how that cutplane cuts through the X-Z plane at 90-degrees, and through the Y-Z plane at an arbitrary angle. Am I missing something?

Re: Can someone explain how to understand Cutplane with thre

Barry Kelly — Fri, 04 Mar 2011 05:50:46 GMT

The example shown doesn't do this.
CUTPLANE angle will give you a cutplan perpendicular to the X-Z plane and at an angle specified around the y-axis.

CUTPLANE x,y,z creates a cutplane that passes through points x distance along the x-axis, y distance along the y-axis and z units along the z-axis.
It can never be perpendicular to any of the axii because you would need to specify an infinite distance to one of the values which is not possible.
However specifying a distance of 0 (zero) to one of the values will ensure the cutplane is perpendicular to that axis (and passing through absolute zero 0,0,0).

At least that is my understanding of the CUTPLANE command.

Barry.

Re: Can someone explain how to understand Cutplane with thre

Anonymous — Fri, 04 Mar 2011 14:55:20 GMT

I have found it almost always easier to make some transformations and use the basic CUTPLANE without arguments. For example:

addx A
roty 90
CUTPLANE
del 2

! stuff to be cut...

CUTEND

Re: Can someone explain how to understand Cutplane with thre

Anonymous — Fri, 04 Mar 2011 15:02:18 GMT

Right. I thought that the image in a previous post was somehow supposed to _show_ a solution to the question that was originally posed, rather than illustrate how CUTEND x,y,z works.