Topic: Blender question: Moving objects in opposite direction

[JanXuan]

How do I move two (or more) vertices, sides of faces simultanously in opposite direction,
such to make sure to obtain a symetrical object.

[kat]

Scale can be used for this, the key is the Pivot Point, so just make sure that's set to "Median Point". Or alternatively snap the cursor to the selection centre ("Shift+S" select "Cursor to Selected") then press "." ("Period/FullStop") to use the Cursor as the Pivot (press "," to revert to default). This only really works well however, if selections are symmetrical, especially where more than two elements are selected, as the action is based on averaging the manipulation across all the selected item. This also affects the use of 'axis locks', pressing "X", "Y" or "Z" after engaging Scale to lock motion to their respective axis.

It can also be done to an extent using "Mirror" but that requires the object(s) to be set up that way for it to be useful (you're mirroring across an axis rather than between a selection).

[JanXuan]

Does using scale this way not affect the size of the selections?
The plan is deforming part of a cylinder symetrically without changing the size of the selection.

Mirror works well when you can make a half object.
I used it for the wing of the airplane. Made one wing first, then mirrored a copy and joined them.

[kat]

If you're able to lock the axis it just changes the distance between selections. Depending on the orientation you may need the change "Transform Orientation" to "Local" or "Normal" to ensure the action is perpendicular to what you're wanting to do as sometimes locking axis isn't possible - especially on non-axial selections. You could also change the Widget type to "Scale" instead of pressing the "S" shortcut, being able to see the widget orientation relative to the outcome you want often helps (doing this tends to work better with complete selections, i.e., selection that would result in an entire face being selected, so 4 verts or one face, edges present a problem because their length can often extend across multiple axis which is why they distort oddly when doing this type of manipulation).

Scaling selection 'freely' versus locked to an axis


Scaling along the 'Normal' axis instead of 'Global'

[JanXuan]

Thank you, this is a big help.
Most of my transformations will be axial.
I also learned that it seems better to start with a higher number of sides to work from rather than starting simple and adding sides later.
With this knowledge I will be doing the fuselage and engine bay all over again. These alone have 12 different cross sections. Starting to learn simple things is not really my habit.