import bpy
import csv
from mathutils import Vector

def import_delta_vertices(filepath):
    # Retrieve the vertex positions from the CSV file
    vertices = []
    with open(filepath, newline='') as csvfile:
        reader = csv.reader(csvfile)
        next(reader)  # Skip the header line
        for row in reader:
            vertex_index = int(row[0])
            delta_x = float(row[1])
            delta_y = float(row[2])
            delta_z = float(row[3])

            # Convert the delta values to a Vector
            delta_vector = Vector((delta_x, delta_y, delta_z))

            # Store the delta vertex position
            vertices.append(delta_vector)

    # Create a new mesh object for the point cloud
    mesh = bpy.data.meshes.new("VertexPositions")
    obj = bpy.data.objects.new("VertexPositions", mesh)

    # Get the active scene
    scene = bpy.context.scene

    # Link the object to the scene
    scene.objects.link(obj)

    # Select and make the object active
    obj.select = True
    scene.objects.active = obj

    # Enter Edit Mode to add vertices
    bpy.ops.object.mode_set(mode='EDIT')
    bpy.ops.mesh.select_all(action='SELECT')
    bpy.ops.mesh.delete(type='VERT')

    # Exit Edit Mode to avoid potential issues
    bpy.ops.object.mode_set(mode='OBJECT')

    # Add the vertices to the mesh
    mesh.from_pydata(vertices, [], [])
    mesh.update()

    print("Vertex positions imported successfully.")

csv_file_path = 'D:/test.csv'
import_delta_vertices(csv_file_path)