Add empty at viewport camera location

add-empty-at-camera.py

import bpy

def get3dViewport():
    for a in bpy.context.window.screen.areas:
        if a.type == 'VIEW_3D':
            print('this ones the 3d viewport')
            viewport = a;
    return viewport;

# create a cameras collection if it doesn't already exist
def createWaypointsCollection():
    if bpy.data.collections.find('waypoints') == -1:
        bpy.data.collections.new('waypoints')
        bpy.data.collections["Collection"].children.link(bpy.data.collections["waypoints"])
        #bpy.data.collections['waypoints'].hide_viewport = True;

def createTrackToEmpty( trackToName='Empty_for_tracking' ):
    if bpy.data.objects.find(trackToName) == -1:
        empty = bpy.data.objects.new("Empty", None);
        empty.name = trackToName;
        bpy.data.collections['waypoints'].objects.link(empty);
        
def createWaypointEmpty(viewport):
    region_3d = viewport.spaces[0].region_3d;
    # https://blenderartists.org/t/how-to-access-the-view-3d-camera/601372/2
    viewport_pos = region_3d.view_matrix.inverted();
    empty_ob = bpy.data.objects.new("Empty", None)
    empty_ob['lens'] = viewport.spaces[0].lens;
    empty_ob['camera_zoom'] = region_3d.view_camera_zoom;
    empty_ob['location_x'] = viewport_pos.translation.x;
    empty_ob['location_y'] = viewport_pos.translation.y;
    empty_ob['location_z'] = viewport_pos.translation.z;
    empty_ob['camera_at_pos'] = viewport_pos.translation;
    empty_ob['track_to_pos'] = region_3d.view_matrix.translation;
    empty_ob['view_matrix'] = region_3d.view_matrix;
    empty_ob.location = viewport_pos.translation;
    return empty_ob;

def removeAllWaypoints():
    if bpy.data.collections.find('waypoints') == -1:
        return;
    # deselect all
    bpy.ops.object.select_all(action='DESELECT');
    # https://wiki.blender.org/wiki/Reference/Release_Notes/2.80/Python_API/Scene_and_Object_API
    for ob in bpy.data.collections['waypoints'].objects:
        ob.select_set(ob.type == 'EMPTY' and ob.name.startswith("Empty"));

    # remove it
    bpy.ops.object.delete();
    

#removeAllWaypoints();
createWaypointsCollection();
createTrackToEmpty('Empty.for.tracking');
viewport = get3dViewport();

empty_ob = createWaypointEmpty(viewport);
bpy.data.collections['waypoints'].objects.link(empty_ob);