Slide edges with absolute values

Question

I have a cylinder I wish to adjust the length of. This is simple when aligned to one of the three axes, as I'd just grab the end edges, set the axis, and type the distance to move by. However, this is not aligned to any axis, thus making this a little more complicated. While I can rotate the whole mesh to align with an axis and follow the aforementioned method, doing this for multiple objects would be time consuming, and I'm wondering if there is a better method.

According to the 2.79 manual, there are vertex and edge slide tools. However, the edge slide shifts the selection by a percentage, not an absolute value. The vertex slide supposedly has a way to set an absolute value by pressing E, then entering your value, but I haven't had much success with it. Both edge and vertex sliding seems to have the same effect, whether I've pressed E or not.

What am I doing wrong here? Alternatively, is there any other way to achieve the desired results?

Answer 1

The quickest way would depend, not on whether the cylinder-object is aligned to the world axes, but on whether the cylinder's mesh is aligned to its own Object (Local) axes.

If the cylinder is aligned to its own axes:

• For an absolute length, you can set its size in that dimension in the 'Dimensions' panel of the properties region of the 3D View, in Object Mode. Beware. This will scale the object's transform matrix. It's probably desirable to CtrlA > Apply the scale, to bake it into the mesh.
• To move one end by a numerically entered amount in Edit Mode, you can just set your Transform Orientation to 'Local' , and (supposing the cylinder was created with Z along its length) hit GZZ [the number].

If the cylinder is not aligned to its own axes:

• You can create a Custom Orientation from a longitudinal edge. Select the edge, and hit CtrlAltSpace. (I usually check 'Use after Creation' and 'Overwrite Previous'.) Now any translation or scale you make with GYY or SYY will be in that edge's direction, and will accept numerical entries.

For absolute transforms, you can always create a jig. Just duplicate, for example, a single vertex at a known zero point, then transform it to the full extent numerically in the desired Transform Orientation, and use it as a snap target for translation, scale, or rotation, before deleting it.