Rip tool

This tool is designed for generating fissures in a mesh. It might become a replacement for the original rip tool in blender.

Usage:

1. Open a text window within blender and open Rip.py in the text window.

2. In a 3D View, click on View -> Space Handler Scripts -> Event: Rip.py in order to activate this script.

3. Get into edit mode and select the editing panel in the buttons window. In Mesh Tools More, click on draw Creases in order to make fissures visible.

4. Select some Edges you want to cut.

5. Press the letter "v". This produces the fissure. As you can see, this also increases the number of vertices and edges.

You are done now. The script does nothing more than this. The last thing the script does is mark the fissure as a crease in order to make it visible.

If you want to know whether it worked or not, just rotate the face around its bottom edge, so you can see you really cut the box open.

Alright, you want to have a more daunting example? Then use the script on a sphere.

Move the four tips horizontally with proportional editing falloff set to "connected". Voilà, this looks almost like a tulip. Note: I have used the set smooth button on all faces (you can find it in the buttons panel, editing section, links and materials).

Try this also with the standard Rip tool (3D View: Mesh -> Vertices -> Rip. See www.blender.org, Development, Release Logs, Blender 2.40, Mesh Ripping).

Comparison of Rip tools
	classic	my tool
pros	switches to grab mode afterwards	almost every selection of edges can be ripped. Exception: single edges.
pros	provides feedback	multiple contiguous sets of edges can be ripped at once.
cons	Not able to rip triangles.	the user has to select one more edge for each end of the fissure.
	Problems ripping some selection of edges that touches a face twice.	does not (yet) provide any feedback except for marking as a crease
	Star-shaped fissure cannot be generated at once.	generated crease might interfere with user's textures (not tested)
	only one contiguous set of edges can be ripped at once.

P.S. I manipulated the images a bit because a window of that size refuses to show vertex counts etc.