I’m trying to figure out how to find the center of 4+ points that I place on a 3D model. I’m placing the points on two separate models (they’re vertebrae) and the center point would lie in the space in between the models.

The centroid of the points would just be the average of the coordinates. If the points are the control points of a markups node, the following would calculate it

```
myMarkupsNode = slicer.util.getNode('F') # replace 'F' with the name of the markups node containing your points
# Calculated center point position
import numpy as np
pointPositionArray = slicer.util.arrayFromMarkupsControlPoints(myMarkupsNode, world=True)
centerPosition = np.mean(pointPositionArray, axis=0)
# Create a new markups node and put a point at the calculated center
centerPointMarkupsNode = slicer.mrmlScene.AddNewNodeByClass('vtkMRMLMarkupsFiducialNode', 'MyCenterPoint')
centerPointMarkupsNode.AddControlPoint(centerPosition)
```