How does Individual Origins calculate the centerpoint on adjacent faces or edges?

The manual says:

Each selected element is transformed around its own centerpoint.

Straightforward enough. Each element (vertex, edge, or face, depending on the current select mode) is transformed around the point on its center. An edge's centerpoint is found on the middle of it, and a face's on the center of it.

When you transform adjacent faces or edges, they are treated as a single element (meaning they don’t become disconnected).

I tested if this was true with an edge of three vertices on (0,0), (1.5,0), and (2,0) (Assume Z axis 0). The pivot point should be on (1,0) when I transform it (e.g. with scale), but it was somewhere between (1.2,0) and (1.3,0).

• Interesting... For edges and vertices it doesn't seem to be median point... May 8, 2023 at 6:47
• @MartynasŽiemys It is, but just as lemon shows in his answer, it is not the median point of the bounding box. And it is the same for faces, too. If you have a simple plane with 4 vertices and set the origin point, then Origin to Center of Mass (Surface) and Origin to Center of Mass (Volume) will give the same result: the visual center of the plane. However, if you make loopcuts off the center, then those two methods will show different results: the Origin to Center of Mass (Volume) is no longer in the visual center of the overall plane, it's shifted towards the higher amount of vertices. May 8, 2023 at 7:12
• @MartynasŽiemys But when you take a cube instead, Origin to Center of Mass (Surface) and Origin to Center of Mass (Volume) again will be the same, no matter if you have off-centered loopcuts leading to an uneven distributed contentration of vertices. But now the option Origin to Geometry will put the origin off the center. By the way, the function Ctrl+S > Cursor to Selected also takes the distribution of vertices into account and places the cursor off the visual median point of the overall selection. May 8, 2023 at 7:17
• @lemon Well, I did - but only for a simple plane with only 4 vertices ;) May 8, 2023 at 7:41
• I tested it May 8, 2023 at 7:55

When individual origins, I presume we cannot scale or rotate vertices individually, so the minimum individual elements are edges.

If we take your example, the first segment center is:

1.5 / 2 => 0.75


and the second is

1.5 + (0.5 / 2) => 1.75


so the mean is

(0.75 + 1.75) / 2 => 1.25


Another way to see it could be:

• take all individual elements centers
• make island defining their center as the mean of the island elements centers
• scale or rotate around that center