# How can I position some elements precisely?

How can I place these arches I made around a center (for example, the origin), in order to make all of them perfectly aligned to X,Y,Z?

Thank you in advance to the kind users

• It seems to me, the more interesting question here is how you place them not in a straight line with the array modifier... Maybe the object has some rotation? What happens if you hit Alt+R to reset rotation? Commented Jul 4, 2023 at 21:31

There are probably hundreds of ways to align objects in Blender. One easy way to align objects that have their origin points in the centers(if you have objects rotated 180° facing each other) would be to scale them to 0 using Affect Only Locations while constrained to desired axis. If you set origin to bounds center before this, it ensures the origins are at centers(this will align origins so it matters where they are). Transform pivot point must not be set to Individual Origins for this to work. It can be any other transform pivot point mode that happens to be convenient for you.

Of course since all transform operators(like G,R,S) take precise numerical inputs or you can use Mirror or Array modifiers it might make sense to place the objects precisely in the first place in this case.

You can use an Empty for that. Create one with Add > Empty > Plain Axes (or another one there) and make it the parent of your arch arrays. Their transforms will be local to the empty now, so you can enter precise convenient offset values (in my example its (3,0,0), (-3,0,0), (0,3,0), (0,-3,0). You can now transform the empty freely and the arches will keep their relative positions.

If you know all your arches will have the same layout you can also use a combination of an Empty and the Mirror modifier. Create an Empty again, but this time you need only one arch array and do not need to parent it. Align it with the Empty to your wished offset, add an Mirror modifier with X and Y activated and set the Empty as the mirror object. Now rotate the Empty 45° around the z-axis. This version keeps you from the hassle to maintain four array copies but obviously it will constrain you to offset them individually.

• Why is the empty needed here? Commented Jul 4, 2023 at 21:27
• I dont get your question, why not? I also explained the advantages, its very useful. Commented Jul 4, 2023 at 21:46
• You don't need an empty to enter precise values. "Their transforms will be local to the empty now, so you can enter precise offset values (in my example its (3,0,0), (-3,0,0), (0,3,0), (0,-3,0)." If you enter precise values during transformations in the first place, what does it matter if they are parented to something or not? You can use an empty for mirror modifier or array with object offset, but why do you need it to just precisely transform objects?.. You don't. Commented Jul 4, 2023 at 21:59
• I did not claim its needed, you may have misunderstood that. OP asked how to align them around "some center", so i showed him an option with local offsets which i believe is more convienient than juggling objects around globally. Commented Jul 4, 2023 at 22:13
• No need for juggling objects around. There is absolutely no need to use an empty to just change transformation pivot point. Transform Pivot Point settings are for that. You can place 3dCursor in the center... I am not sure I follow... Commented Jul 4, 2023 at 22:17