vertex key trouble

I m still investigating blender. and here is my day work. understanding vertex key and driven shape key.
but i notice some strange behavior in shape key. could you confirm that it not suppose to do that.
I select a cube set a vertex key as basis. i select 2 vertices move it up and reselect the whole cube and add a new key. i do the same one more time but moving some other vertices down.
the first thing is when you create the second vertex key, there is no way to get the basis key for starting. you need to start sculpting the new key from the last key done. if you want to start from the basis you got to go in object mode switch to basis, then go back in edit mode. is there an other way to do?
the second is each time i switch from one key to another the slider is at 0 but it s like it was at one. If you move the cursor it s ok, but i would prefer that 0=0 and 1=1. is that a trouble or the normal behavior.

should it be reported as bug?(i don t want to bother devel team if it s normal)

No, it’s not a bug. When you goto the IPO window and select Basis from the righthand column (and I think when you select it from the dropdown in the Shapes tab too but I don’t have Blender here to test) the Basis shape will be drawn in the 3D Viewport.

Basically, Basis is the verts in their original cubic positions.
Key1 is “Two verts up and two verts down” relative to their original cubic positions.
Key2, if you use the same “two verts and two verts” (and let’s say moved them sideways) would still be relative to Basis and not Key1 (your problem is just that while in Key1 you can’t see the starting points (basis positions) or frame one positions.

Also, don’t think of Shapes as Basis = lips, Key1 = smile, Key2 = smile more. It should be Basis to Smile Most and then the IPO will determine how much to smile on which frame(s). Key2 should be used for Mouth Open so you can run Smile and MouthOpen concurrently and mix them to make Laugh.


the shape are build upon the previous, and not upon the basis. That s why i got some trouble, and i need to switch to object mode and reset the shape to basis before to do a new key. but i will try to investigate that a bit more tomorow and may be making a video so as to be clear.