I see this asked frequently in the AutoCAD forums “How do
I get the bounding box of an entity”, and the standard answer is usually, “Use vla-GetBoundingBox”,
or get the entity extents. This is the correct answer, caveat, the bounding box
is aligned with WCS, so if your object is rotated the result may not be what
you need.
One option is to transform the object to align with WCS.
Or we can use a 3rd party tool like Python’s shapely to help.
here's an example:
import traceback
import PyRx as Rx
import PyGe as Ge
import PyGi as Gi
import PyDb as Db
import PyAp as Ap
import PyEd as Ed
from shapely import LineString
def PyRxCmd_doit():
try:
#create a selection set filter and select the polylines
filter = [(Db.DxfCode.kDxfStart, "LWPOLYLINE")]
ss = Ed.Editor.selectPrompt(
"\nSelect parts: ", "\nRemove parts: ", filter)
if ss[0] != Ed.PromptStatus.eNormal:
return
#iterate the selection set
for id in ss[1].objectIds():
#create a LineString from our polylines
pline = Db.Polyline(id)
ls = LineString(pline.toList())
#get the oriented bbox
coords = ls.oriented_envelope.exterior.coords
#convert tuples to Ge.Point3d
points = [Ge.Point3d(p) for p in coords]
# #draw the results
Ed.Core.grDraw(points[0], points[1],1,0)
Ed.Core.grDraw(points[1], points[2],1,0)
Ed.Core.grDraw(points[2], points[3],1,0)
Ed.Core.grDraw(points[3], points[0],1,0)
except Exception as err:
traceback.print_exception(err)