Scripting Leader Arrow Type

Is it possible to change the arrow type for leaders using Rhinoscriptsyntax or rhinocommon? Here’s what I have so far.

import rhinoscriptsyntax as rs
import Rhino

def LeaderArrowType():
leaders = rs.GetObjects(“Choose leaders to change”, rs.filter.annotation, preselect=True)
if not leaders: return

for leader in leaders:
    leader = rs.coercerhinoobject(leader)
    arrowStyle = Rhino.DocObjects.DimensionStyle.ArrowType.Dot
    leader.Geometry.LeaderArrowType = arrowStyle


This doesn’t seem to be working. I’m guessing that “leader.Geometry.LeaderArrowType” can on get the arrow type, not set it?

Thanks All :grinning:

Hi, does this discussion help?

Are you using version 5 or 6? Windows or mac?
Seems it makes a difference

Windows version 6.

That thread seems to be about altering dimstyles rather than overriding a particular instance.

I was thinking I could delete the leader and create a new one from scratch, but

Rhino.Geometry.Leader.Create(text, Plane, dimstyle, points)

Doesn’t set the arrow type on creation, so it would be the same issue with overriding a particular instance as before.

I think that I first need to create an overiding dimension style:

overideStyle = Rhino.DocObjects.DimensionStyle()

then change the properties of the instance to change:


I don’t yet know how to modify the overideStyle dimension style to have a different arrow type though…

Hi @Alasdair, may below helps, works in Rhino 6:

import Rhino
import scriptcontext
import rhinoscriptsyntax as rs

def DoSomething():

    leader_id = rs.GetObject("Select leader", rs.filter.annotation, True, False)
    if not leader_id: return
    leader_obj = rs.coercerhinoobject(leader_id, True, True)
    if not isinstance(leader_obj, Rhino.DocObjects.LeaderObject): return
    new_style = Rhino.DocObjects.DimensionStyle()
    new_style.LeaderArrowType = Rhino.DocObjects.DimensionStyle.ArrowType.Dot



Yep that does the job! Thanks

Do you know if there’s a way to access/modify horizontal justification of a leader in python (R6)?

Hi @Asterisk, you might try below code in above example which creates an override, or use it in your dimension style:

h_align = Rhino.DocObjects.TextHorizontalAlignment.Right
new_style.LeaderTextHorizontalAlignment = h_align



Thanks! This works.

Ldr = rs.coercerhinoobject(Ldr_GUID, True, True)
Ldr.LeaderGeometry.LeaderTextHorizontalAlignment = Rhino.DocObjects.TextHorizontalAlignment.Right

Is there any other way to create “Rhino.DocObjects.TextHorizontalAlignment.Right” variable?

1 Like

Hi @Asterisk, i don’t think so, it seems to be RhinoCommon only.