Knife for AC3DReleased under the GNU LESSER GENERAL PUBLIC LICENSE.
Previous release (version 1.1.2)
* NOTE: Courtesy of AJ MacLeod, the Linux version was compiled and linked on a Debian 3.0 install. If this does not work for you, the source code has been proven to compile/link under Linux, so you may wish to download the source code and compile for your system.
**NOTE: Courtesy of Eldon Brown. From the enclosed Readme:
Fixes in version 1.2.2:
Fixes in version 1.2.1:
Fixes in version 1.2:
Fixes in version 1.1.2:
Improvements made in version 1.1:
Known issues and Limitations:
Acts on the edges of the selected objects/surfaces, inserting a vertex where necessary. Optionally performs a Slice Surface.
This plugin and code are freely distributable
AC3D versions prior to version 5 have not been tested with this script.
The interface options are as follows:
Knife is an AC3D plugin that allows you to insert vertices (and optionally slice surfaces) in the selected object(s).
Copy the knife.tcl and knife.p files to your AC3D plugins folder (for example, if using Windows, C:\Program Files\AC3D5\plugin) and (re)start AC3D.
You will find the "Knife..." menu item under the "Tools" menu.
Example : Slicing a sphere with a cutting plane
In this example we'll slice a sphere across an arbitrary plane.
First, create a sphere with a fairly high density - I used 48. Then, create a rectangle that completely intersects the sphere at an angle. I created a rectangle on the "top" view that completely enclosed the top view of the sphere, then rotated the rectangle 35 degrees.
We'll slice the sphere where it is intersected by the rectangle, then delete the rectangle. To do this, perform the following steps:
1. Select the "Knife..." menu item under the "Tools" menu. This brings up the Knife interface.
2. Select the rectangle object and click "Set knife" to make the rectangle your knife object.
3. Ensure that "Slice surfaces", "Cut away object", and "Delete knife" are all checked. "Slice surfaces" will cause all of the edges of the sphere than intersect the plane to be sliced where they meet. "Cut away object" will cause the sphere to be split into two objects. "Delete knife" will cause the rectangle to be deleted.
4. Select the sphere and click "Slice".
If you followed these steps, you should end up with two halves of a sphere, below.
IGNORE THE SURFACES INDICATED BY THE RED ARROW: This points out a legacy problem where surfaces were not sliced properly (old attributes were not kept, such as 1/2 sided, material, etc - only geometry). This has been addressed/fixed in the latest version. These screenshots have not yet been updated to reflect the new fixes.
Example : Slicing a sphere with a shape
You can use any single object as a knife. Here, we'll try a cylinder. Using the same sized sphere as before, this time create a cylinder that passes through the entire sphere like so:
Repeat the same steps as with the rectangle slice in the previous example, only using the cylinder as the knife object.
The cut-away surfaces will be those "outside" or "in front of" the cylinder's surfaces. You can see which way a surface faces by showing Normals --- try showing normals in the 3D view (by pressing the "n" key while the mouse is in the 3D view). You'll see lines coming from the surfaces indicating which way the surfaces face. The knife tool separates surfaces "outside" or "in front of" the knife object from those "inside" or "behind" the knife object.
If you followed the same steps, you should end up with something like this.
|All content Copyright © 2006 Dennis Hawthorne, except where explicitly noted
supercoldmilk © 2006 Dennis Hawthorne