Undo Redo Maya API problem

[justin hidair]

Wrote something cool, implemented all the required method,

doIt() and redoIt works , undoIt() don't.

When I undo the object disappear, why ???
I didn't touch anything related to object visibility, I even tried to refresh the viewport , still nothing...

In doIt/redoIt method I use setVertexNormals()


MStatus setVertexNormals

	(	MVectorArray &	normalsIn,
		MIntArray &	vertexList,
		MSpace::Space	space = MSpace::kObject
	)

Set Shared Normals for these vertices.

The length of the normalsIn array should be same as the length of the vertexList array.

Parameters

[in]	normalsIn	The normals to set
[in]	vertexList	The object-relative (mesh-relative/global) vertex indices to set them for
[in]	space	World space or Object space

as you can see it doesn't take a MDGModifier but setVertexNormal do :

MStatus setVertexNormal

	(	MVector &	normalIn,
		int	vertexId,
		MSpace::Space	space = MSpace::kObject,
		MDGModifier *	modifier = NULL
	)

Set Shared Normal for this vertex.

Parameters

[in]	normalIn	The normal to set
[in]	vertexId	The object-relative (mesh-relative/global) vertex index to set it for
[in]	space	World space or Object space
[in,out]	modifier	Since this method may modify the DG, if you wish to undo its effects, you need to keep track of what needs to be undone. If the modifier is non-null, and this MFnMesh refers to a shape, then it will add the command to be undone to the modifier. Use MDGModifier::undoIt to undo the effects of this method. setVertexNormal is a pain in the ass performance wise, so I don't want to use it...

[justin hidair]

a MEL command that created a Node made this, this MEL command also modifies the apparence of the mesh has it is cmds.polySoftEdge() ... so if someone gets here would you tell me how to properly undo the change made by a MEL command in a plugin within undoIt() method ? or tell me if It's just me and I'm screwing something ?

PS : I finally found a way but without using the MEL command above, It'll still be interesting to have an answer to the latter question thanks :)

[justin hidair]

also for some reason I can Undo , but at one point it will go Undo : Redo , and Redo : Redo

[justin hidair]

ok this is because again of a MEL command , just realise there is om.MGlobal.executeCommand() to properly do this,  using it prevent the plugin from doing 'shit' , ho Api..