hohehohe2's OpenMaya tutorial
kotamuraa@yahoo.co.jp
Sup 1: undo and redo
Command plug-in has a very important rule.
"When a command plug-in changes a scene, you must make the
command undoable/redoable"
"When undo is executed, the scene state must be completely reverted
to the previous one,
including selection of scene objects"
To explain it why, suppose you have done two manipulations.
-A: move a nurbs sphere.
-B: execute a plug-in command.
If you undo them, first B is undoed, then A is undoed.
Now suppose B deleted the nurbs sphere moved by A.
If the implementation of B is bad, and "undo B" doesn't
resurrect the sphere, "undo A" cannot be done successfully
since there is no nurbs sphere to move back. Thus Maya's
undo mechanism will be destroyed.
Prev Contents Next
Maya is a registered
trademark of Autodesk
Copyright ©
2003, Koichi Tamura. All Rights Reserved.