Rotate a group of meshes at the center of group

Hi, I’m having a hard time rotating a mesh group, when I change the rotation of a group it rotates around the origin O as picture below.

Is there any way to rotate only around the center of the group?
Can anyone help me?

Update: Sorry for the confusing question, the rotation of picture 1 is (x: 0, y:0, z:0) when I set the rotation of z as 45 degrees, it becomes picture 2. (The number 0 and the group of small squares are individual objects)

pic 1: Before rotate

pic 2: After rotate 45 degrees

To rotate a single group about its origin, see this.

I’m a little confused though because you’re talking about “a group”, then about “these groups”. And a (one) group in 2D has 2 components to its origin, x and y, so you can’t specify a group’s (or mesh’s) origin by just one number. In 3D that’s even 3 components: x, y, z.

Assuming you are talking of one (1) group consisting of three meshes, you’ll have to specify which point you’ll want to consider to be the center of that group.

If the center of geometry of the group is (22, 14, 13).
Set position of the group to (-22, -14, -13);

Sorry for the confusing question, I have updated the topic, can you please help me?

I have tried many ways but it still rotates around the A point in the above pictures

From pic1:

  • move mesh/group from Postion A (x, y, z) to center of rotation (0, 0, 0).
  • rotate mesh/group about z.axis by 45°
  • move mesh/group back to Postion A (x, y, z)