Setting Pivot/ Object transformation

[TomD_Arch]

I have a plain in elevation and I wanted to reset the pivot point to the bottom of the plain and I could then set the object to zero elevation. I then expected if changed the height the plain would grow taller or shorter, but the bottom would stay anchored at zero now that I've used Heirarchy>Pivot>Affect Pivot Only. Instead what happens is the plain transforms via the center still, growing or shrinking in both the z directions at once. I don't ever recall this happening before. Can someone make any suggestions? What don't I understand here?

[heni30]

It seems like the pivot point works with transformations; not with changing the height with original creation text imput. If you scale it it will work, figuring out your scale %. You can move the vertices up by typing in an amount in the z direction or manually by rolling the text spinner. You can align the vertices to an object of your desired height.

[Tommy L]

The plane is a parametric object. If you want to scale it numericaly then you would collapse it to a poly then move the pivot point then scale.