Is dup’ing the edges, simplifying curves and making a new brep the only way?
Before trimming, make sure the trim curve is split at kinks. Afterwards, you can use BrepEdgeList.SplitKinkyEdge.
def test_split_kinky_edges():
filter = Rhino.DocObjects.ObjectType.Surface | Rhino.DocObjects.ObjectType.PolysrfFilter
rc, objref = Rhino.Input.RhinoGet.GetOneObject("Select surface or polysurface", False, filter)
if not objref or rc != Rhino.Commands.Result.Success:
return
brep = objref.Brep()
if not brep:
return
tol = Rhino.RhinoMath.DefaultAngleTolerance
bcopy = brep.DuplicateBrep()
for i in range(0, bcopy.Edges.Count):
bcopy.Edges.SplitKinkyEdge(i, tol)
bcopy.Compact()
sc.doc.Objects.Replace(objref, bcopy)
sc.doc.Views.Redraw()
– Dale
I’m trimming with a pipe “poly” brep, so no curves involved. But Edges.SplitKinkyEdge did the trick! Thanks Dale!
hi @dale,
sorry for bringing this issue up 2 years after it’s been created.
Does this mean BrepEdgeList.SplitKinkyEdge only works if the trim curve has been split at kinks?
In my case I have input I did not create myself. Sometimes it is really really messy.
So I tried to merge the edges before, because it usually contains a lot of linear edges that actually can be merged. But the result is that e.g. the highlighted edge shoud rather consist of a linear and a curved pard.
SplitKinkyEdge does not work… Acutally I think here a method like SplitAtTangents would be required, but I cannot find any.
Is there any solution to this?
Thanks,
T.
Does what mean?
So what problem are you trying to solve? Perhaps posting a 3dm file might be helpful?
Thanks,
– Dale
@dale
Sorry, I thought it was clear that I was referring to your code.
I also have to admit that in my comment I made my own thought kind of obsolete.
First I thought that splitting brep edges at “kinks” is achieved by BrepEdgeList.SplitKinkyEdge.
What I actually meant is that in this case we are not talking about kinky edges, but we want to split edges at tangents, right?
Here is a file which contains a brep with an edge that acutally consists of two pieces.
It is highlighted with a textdot.
ExampleEdges.3dm (42.0 KB)
I’ll go back to my previous question:
Pretend I know nothing. What problem are you trying to solve?
You’ve posted a valid surface that appears to have some of its edges split. So that is the goal? To merge all edges? To split more edges? Why do you care about any of this?
– Dale
hi @dale,
sorry.
I have to analyze each edges connection to geometry (lines, which are profiles) above these panels (aka. the surface).
Not knowing how “good” my input is (as this is coming from another party) I would like to have a “clean” geometry, meaning that if I analyze a brep edge there is not a second one next to it that actually is colinear. Also it would be very helpful for me that if a curve consists of a linear and curved part these would be two pieces.
Of course I now understand that I might duplicate the surface border, simplify it and process it, but in my eyes it is quite convenient to get this information from the surface/brep, as I would groom this once and I could save it like that for good.
Hope this makes sense. 
You might start off by merging all edges. Rhino has a command for for that - MergeAllEdges. You can also do this via code.
import Rhino
import scriptcontext as sc
import System
def test_merge_all_edges():
go = Rhino.Input.Custom.GetObject()
go.SetCommandPrompt("Select Brep")
go.GeometryFilter = Rhino.DocObjects.ObjectType.Brep
go.Get()
if go.CommandResult() != Rhino.Commands.Result.Success:
return
objref = go.Object(0)
brep = objref.Brep()
if brep:
print("Original edge count: {0}".format(brep.Edges.Count))
brep_copy = brep.DuplicateBrep()
ang_tol = System.Math.PI / 180.0
merge_count = brep_copy.Edges.MergeAllEdges(ang_tol)
if merge_count > 0:
print("Merged edge count: {0}".format(brep_copy.Edges.Count))
sc.doc.Objects.Replace(objref, brep_copy)
sc.doc.Views.Redraw()
if __name__ == "__main__":
test_merge_all_edges()
– Dale
1 Like
Hi @dale,
thanks! This works fine. But there is no way to split brep edges at tangents after doing MergeAllEdges, correct?
RhinoCommon does not have a method to split Brep edge at tangent locations.
However, you might be able to code your own solution. Here is where you might start:
import Rhino
def BrepSplitEdgeAtTangents(brep, edge_index):
if brep is None:
return None
if edge_index < 0 or edge_index >= brep.Edges.Count:
return None
curve = brep.Edges[edge_index];
t0 = curve.Domain.Min;
t1 = curve.Domain.Max;
continuity = Rhino.Geometry.Continuity.G2_continuous
params = []
while t0 < t1:
rc, t = curve.GetNextDiscontinuity(continuity, t0, t1)
if rc:
if t < t1 or (curve.IsClosed and t <= t1):
parameters.append(t)
t0 = t
continue
else:
break
if len(params) > 0:
params.sort()
params = list(set(params))
rc = brep.DuplicateBrep()
rc.Edges.SplitEdgeAtParameters(edge_index, params)
rc.Compact()
return rc
return None
Note, I have not tested this…
– Dale