Welds the points of a cube so that it looks like a tent.

WeldCubePoints.py

"""Weld Cube Points
Welds cube points together.

Usage Instructions:
1. Create some cubes.
2. Make them editable
3. Run this script.
"""

import c4d

def SquishPoints(cube):
    """Welds the top 4 points of a polygon Cube."""
    
    if (cube is None) or (not cube.IsInstanceOf(c4d.Opolygon)):
        return

    points = cube.GetAllPoints()
    point_id_groups = [[1,3],[5,7]]  # Split into sub-lists so each can be welded in turn.
    
    # Go through each set of points to weld.
    for point_id_group in point_id_groups:
        # Weld command isn't easily called via script, so we'll move the points we want to weld
        # to the same position, then call the Optimize command.
        
        # Calculate the center of the points
        point_position_sum = c4d.Vector(0.0)
        for point_id in point_id_group:
            point_position_sum += points[point_id]
            
        number_of_points = len(point_id_group)
        center_point = point_position_sum / number_of_points
        
        # Move points to the center
        for point_id in point_id_group:
            points[point_id] = center_point

    # Store the changed points
    cube.SetAllPoints(points)

def main():
    # Get a list of active objects.
    active_objects = doc.GetActiveObjects(flags=c4d.GETACTIVEOBJECTFLAGS_0)
    
    # Start recording changes you'll later want to undo.
    doc.StartUndo()
    
    # Squish together the points for all selected objects
    for obj in active_objects:
        doc.AddUndo(c4d.UNDOTYPE_CHANGE, obj)
        SquishPoints(obj)
    
    # Use the optimize command to weld them
    c4d.CallCommand(14039, 14039) # Optimize...
    
    # Let C4D know that something has happened and it should redraw.
    doc.EndUndo()
    c4d.EventAdd()
    
if __name__=='__main__':
    main()