While selecting a mesh and clicking on the CVs in the Channel Box, if I right click on say the X axis and choose Lock Selected, I am unable to translate the vertex in all three axis. 
However, if I choose Breakdown Selected on just X axis, then as expected, only the X axis will take keys and allow the vertex to snap back to the position in X that was keyed.
When I use the MEL commands to set a breakdown versus a lock on the X axis position, I run into the same results, where Lock on X axis prevents any movement in all directions, but setting a breakdown key on just X will allow the the Y and Z to stay in position when change the current frame on the timeline.
Use the example code then translate in X,Y, & Z.
Then press the Start of Playback animation controls for the Vertex to snap back in only the X axis.
polySphere -r 1 -sx 20 -sy 20 -ax 0 1 0 -cuv 2 -ch 1;
setKeyframe -breakdown true ".pt[200].px";
select .vtx[0:381] ;
setToolTo $gMove;
For the next example, delete the first sphere and run the code below.
A vertex is locked in only X axis, as you can see the .px prefix that is also used in the breakdown.
However, the vertex will not move in any axis as creating undesired results of being locked in XYZ.
polySphere -r 1 -sx 20 -sy 20 -ax 0 1 0 -cuv 2 -ch 1;
setAttr -lock true ".pt[200].px";
select .vtx[0:381] ;
setToolTo $gMove;
Is there another way to prevent a vertex position from moving in a single axis without setting key data? I would like to lock 402 verts from only moving in the Y axis in my script.
Thanks!
[This was tested in Maya 2010 and Maya 2011]
