# Erasing points inside a Toposurface using Python in Dynamo

**URL:** <https://forum.dynamobim.com/t/erasing-points-inside-a-toposurface-using-python-in-dynamo/98532>\
**Category:** Revit\
**Tags:** python, dynamo\
**Created:** [February 27, 2024, 4:23pm UTC](https://forum.dynamobim.com/t/erasing-points-inside-a-toposurface-using-python-in-dynamo/98532 "2024-02-27T16:23:02Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![luisaECXV3](https://avatars.discourse-cdn.com/v4/letter/l/e36b37/32.png) [@luisaECXV3](https://forum.dynamobim.com/u/luisaECXV3)\
**Post date:** [February 27, 2024, 4:23pm UTC](https://forum.dynamobim.com/t/erasing-points-inside-a-toposurface-using-python-in-dynamo/98532/1 "2024-02-27T16:23:02Z")

</div>

In Python 3 inside Dynamo for Revit 2023 I am trying and failing to erase all the interior points inside a Toposurface using Python. My script goes as follows:

```auto

# Import necessary CLR assemblies and references
import clr
clr.AddReference('RevitAPI')
clr.AddReference('RevitAPIUI')
clr.AddReference('ProtoGeometry')
clr.AddReference('RevitNodes')
clr.AddReference('RevitServices')

# Import Revit API namespaces
from Autodesk.Revit.DB import *
from Autodesk.Revit.DB.Architecture import *
from Autodesk.Revit.UI import *

# Import RevitNodes to allow for Dynamo & Revit type conversions
import Revit
clr.ImportExtensions(Revit.Elements)
clr.ImportExtensions(Revit.GeometryConversion)

# Import RevitServices for Document and Transaction management
from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager

# Define a custom failure processor by implementing the IFailuresPreprocessor interface
class CustomFailureProcessor(IFailuresPreprocessor):
    def PreprocessFailures(self, failuresAccessor):
        # Ignore all failures for simplicity
        failures = list(failuresAccessor.GetFailureMessages())
        for failure in failures:
            failuresAccessor.DeleteWarning(failure)
        return FailureProcessingResult.Continue

# Get the current Revit document from the Document Manager
doc = DocumentManager.Instance.CurrentDBDocument

# Assuming the input is a topography surface element wrapped in Dynamo
topoSurface = UnwrapElement(IN[0]) # Unwrap the Dynamo element to get the Revit element

# Get the interior points of the topography surface
interiorPoints = topoSurface.GetInteriorPoints()

# Begin a transaction to modify the document
TransactionManager.Instance.EnsureInTransaction(doc)

# Define a scope for editing the topography, required for certain operations
topoEditScope = TopographyEditScope(doc, "Edit Topography Scope")
topoEditScope.Start(topoSurface.Id)

try:
    # Perform the operation: Delete interior points from the topography surface
    topoSurface.DeletePoints(interiorPoints)
    doc.Regenerate()
finally:
    # Always ensure to close the TopographyEditScope properly
    topoEditScope.Commit(CustomFailureProcessor())

# End the transaction
TransactionManager.Instance.TransactionTaskDone()

# Output the number of deleted points for verification
OUT = len(interiorPoints)

```

However I get the error “InvalidOperationException”: This TopographyEditScope is not permited to start at this moment for one of the possible reasons: The document is in read-only state, or the document is currently modifiable, or there already us another edit mode active in the document. And ok, I get it, I am already opening a transaction. However if I access the TopographyEditScope without the TransactionManager.Instance.EnsureInTransaction(doc) it says I need a previous transaction for the TopographyEditScope to start. Grouping the transactions does not seem to be working either. Has anyone solved a similar issue?  
[R23\_TopographyEditScope.dyn](https://forum.dynamobim.com/uploads/short-url/ovvKYilf5ShmrP1r33ytlKmgl1R.dyn) (6.5 KB)

---

<div class="post-metadata">

**Author:** ![Draxl\_Andreas](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/draxl_andreas/32/145744_2.png) [@Draxl\_Andreas](https://forum.dynamobim.com/u/Draxl_Andreas)\
**Post date:** [February 27, 2024, 8:52pm UTC](https://forum.dynamobim.com/t/erasing-points-inside-a-toposurface-using-python-in-dynamo/98532/2 "2024-02-27T20:52:38Z")

</div>

@luisaECXV3 ,

here your clean code, at first view looks like AI generated and evaluated by a real brain. So i would not open a transaction in a transaction.

```auto

import clr
clr.AddReference("RevitAPI")
clr.AddReference("RevitAPIUI")
clr.AddReference("ProtoGeometry")
clr.AddReference("RevitNodes")
clr.AddReference("RevitServices")

from Autodesk.Revit.DB import *
from Autodesk.Revit.DB.Architecture import *
from Autodesk.Revit.UI import *

import Revit
clr.ImportExtensions(Revit.Elements)
clr.ImportExtensions(Revit.GeometryConversion)

from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager

doc = DocumentManager.Instance.CurrentDBDocument

# 0️⃣ Define a custom failure processor by implementing the IFailuresPreprocessor interface
class CustomFailureProcessor(IFailuresPreprocessor):
    def PreprocessFailures(self, failuresAccessor):
    # 💤 Ignore all failures for simplicity
        failures = list(failuresAccessor.GetFailureMessages())
        for failure in failures:
            failuresAccessor.DeleteWarning(failure)
            return FailureProcessingResult.Continue 

# 1️⃣ Assuming the input is a topography surface element wrapped in Dynamo
topoSurface = UnwrapElement(IN[0]) 

# 2️⃣ Get the interior points of the topography surface
interiorPoints = topoSurface.GetInteriorPoints()

# 🔓 Begin a transaction to modify the document
TransactionManager.Instance.EnsureInTransaction(doc)

# Define a scope for editing the topography, required for certain operations
topoEditScope = TopographyEditScope(doc, “Edit Topography Scope”)
topoEditScope.Start(topoSurface.Id)

try:
    # Perform the operation: Delete interior points from the topography surface
    topoSurface.DeletePoints(interiorPoints)
    doc.Regenerate()
finally:
    # Always ensure to close the TopographyEditScope properly
    topoEditScope.Commit(CustomFailureProcessor())

# 🔒 End the transaction
TransactionManager.Instance.TransactionTaskDone()

# ✅ Output the number of deleted points for verification
OUT = len(interiorPoints)

```

i can not replicate your topic directly. will see what others write…

```auto
# 🔓 Begin a transaction to modify the document
t = Transaction(doc, "Edit Topography Scope")
t.Start()

# Define a scope for editing the topography, required for certain operations
topoEditScope = TopographyEditScope(doc)

try:
    # Perform the operation: Delete interior points from the topography surface
    topoSurface.DeletePoints(interiorPoints)
    doc.Regenerate()
except:
    # Always ensure to close the TopographyEditScope properly
    topoEditScope.Commit(CustomFailureProcessor())

# 🔒 End the transaction
t.Commit()

```

KR

Andreas

---

<div class="post-metadata">

**Author:** ![luisaECXV3](https://avatars.discourse-cdn.com/v4/letter/l/e36b37/32.png) [@luisaECXV3](https://forum.dynamobim.com/u/luisaECXV3)\
**Post date:** [February 28, 2024, 11:58am UTC](https://forum.dynamobim.com/t/erasing-points-inside-a-toposurface-using-python-in-dynamo/98532/3 "2024-02-28T11:58:13Z")

</div>

First, thank you very much for replying, Andreas. So, I tried following the steps you mentioned for setting up the transactions, but for some reason, the `DeletePoints` method still isn’t playing ball. I went back, double-checked everything, and even swapped `TopoSurface` for `Topography` , making sure to pack the interior points into an `IList` since that seemed to be what `DeletePoints` was looking for. But, guess what? Those points are still there, as if they’re mocking me. I even went the extra mile to make sure they were actually gone, but no luck. So, what gives? Is the `DeletePoints` method just messing with me, or am I missing something obvious here?  
[R23\_TopographyEditScope\_V2.dyn](https://forum.dynamobim.com/uploads/short-url/erEs0Xn52y7AumrFxyEKVAUAmAo.dyn) (7.2 KB)  
[R23\_Topo.rvt](https://forum.dynamobim.com/uploads/short-url/yey72O0LIMsiAXSuWwV7ZZCI9Sr.rvt) (4.4 MB)

```auto
# Import necessary CLR assemblies and references
import clr
clr.AddReference('RevitAPI')
clr.AddReference('RevitAPIUI')
clr.AddReference('ProtoGeometry')
clr.AddReference('RevitNodes')
clr.AddReference('RevitServices')

# Import Revit API namespaces
from Autodesk.Revit.DB import *
from Autodesk.Revit.DB.Architecture import *
from Autodesk.Revit.UI import *

# Import RevitNodes to allow for Dynamo & Revit type conversions
import Revit
clr.ImportExtensions(Revit.Elements)
clr.ImportExtensions(Revit.GeometryConversion)

# Import RevitServices for Document and Transaction management
from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager

# Add .NET collections import
from System.Collections.Generic import List

# Get the current Revit document from the Document Manager
doc = DocumentManager.Instance.CurrentDBDocument

# Getting the topography with a Filter. At first I tried getting the Toposurface directly and this gave me nothing, so new approach:
topoSurfaces = FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_Topography).ToElements() 

# Get the interior points of the topography surface
interiorPoints=[]
# Get the interior points of the topography surface and delete them
for topoSurface in topoSurfaces:
    pythonList = topoSurface.GetInteriorPoints() # This gets the points as a Python list
    
    # Convert Python list to .NET IList[XYZ]. Realized this method needed an IList. Still not working anyway.
    interiorPoints = List[XYZ](pythonList)
    
    t = Transaction(doc, "Edit Topography Scope")
    t.Start()
    topoEditScope = TopographyEditScope(doc, "Topo")
    
    try:
        # Perform the operation: Delete interior points from the topography surface, this is what is not working and I can't guess what the problem is
        topoEditScope.Start()
        topoSurface.DeletePoints(interiorPoints)
        doc.Regenerate()
        topoEditScope.Commit()
    except Exception as e:
        OUT = e
        topoEditScope.Dispose() 
    finally:
        # End the transaction
        t.Commit()

newTopoPoints=topoSurface.GetInteriorPoints()
# Doble checking. Still no points deleted
OUT = pythonList,newTopoPoints, topoSurfaces

```

---

<div class="post-metadata">

**Author:** ![jacob.small](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/jacob.small/32/161030_2.png) [@jacob.small](https://forum.dynamobim.com/u/jacob.small)\
**Post date:** [February 28, 2024, 12:09pm UTC](https://forum.dynamobim.com/t/erasing-points-inside-a-toposurface-using-python-in-dynamo/98532/4 "2024-02-28T12:09:41Z")

</div>

> [@luisaECXV3](#):
>
> Is the `DeletePoints` method just messing with me, or am I missing something obvious here?

Can you send a link to which method you are attempting to use? I believe that delete points is a member of the TopographySurface class, not topographies in general.

Also I find it best to build your initial functions without a ‘try’ as it masks the errors which pop up. I would guess this is what you are seeing as you set OUT to the exception, but then later on redefine it as something else, thereby masking the exception entirely.

---

<div class="post-metadata">

**Author:** ![luisaECXV3](https://avatars.discourse-cdn.com/v4/letter/l/e36b37/32.png) [@luisaECXV3](https://forum.dynamobim.com/u/luisaECXV3)\
**Post date:** [February 28, 2024, 1:19pm UTC](https://forum.dynamobim.com/t/erasing-points-inside-a-toposurface-using-python-in-dynamo/98532/5 "2024-02-28T13:19:21Z")

</div>

Of course. This is the method I am attempting to use [DeletePoints Method](https://www.revitapidocs.com/2024/06206e0f-db70-d184-1f13-d9a787e8fd98.htm) it is indeed a TopographySurface Method, but so is GetInteriorPoints(), which is working correctly. When I remove the try and except like this:

```auto
# Import necessary CLR assemblies and references
import clr
clr.AddReference('RevitAPI')
clr.AddReference('RevitAPIUI')
clr.AddReference('ProtoGeometry')
clr.AddReference('RevitNodes')
clr.AddReference('RevitServices')

# Import Revit API namespaces
from Autodesk.Revit.DB import *
from Autodesk.Revit.DB.Architecture import *
from Autodesk.Revit.UI import *

# Import RevitNodes to allow for Dynamo & Revit type conversions
import Revit
clr.ImportExtensions(Revit.Elements)
clr.ImportExtensions(Revit.GeometryConversion)

# Import RevitServices for Document and Transaction management
from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager

# Add .NET collections import
from System.Collections.Generic import List

# Get the current Revit document from the Document Manager
doc = DocumentManager.Instance.CurrentDBDocument

# Getting the topography with a Filter. At first I tried getting the Toposurface directly and this gave me nothing, so new approach:
topoSurfaces = FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_Topography).ToElements() 

# Get the interior points of the topography surface
interiorPoints=[]
# Get the interior points of the topography surface and delete them
for topoSurface in topoSurfaces:
    pythonList = topoSurface.GetInteriorPoints() # This gets the points as a Python list
    
    # Convert Python list to .NET IList[XYZ]. Realized this method needed an IList. Still not working anyway.
    interiorPoints = List[XYZ](pythonList)
    
    t = Transaction(doc, "Edit Topography Scope")
    t.Start()
    topoEditScope = TopographyEditScope(doc, "Topo")    
    topoEditScope.Start(topoSurface.Id)
    topoSurface.DeletePoints(interiorPoints)
    doc.Regenerate()
    topoEditScope.Commit()
    t.Commit()

newTopoPoints=topoSurface.GetInteriorPoints()
# Doble checking. Still no points deleted
OUT = pythonList,newTopoPoints, topoSurfaces

```

I get the error: “TopographyEditScope is not permitted to start at this moment for one of the following possible reasons: The document is in read-only state, or the document is currently modifiable, or there already is a topography surface edit mode active in the document.” Obviously the document is being edited, we started a transaction here. But if I remove the document transaction like this:

```auto
# Import necessary CLR assemblies and references
import clr
clr.AddReference('RevitAPI')
clr.AddReference('RevitAPIUI')
clr.AddReference('ProtoGeometry')
clr.AddReference('RevitNodes')
clr.AddReference('RevitServices')

# Import Revit API namespaces
from Autodesk.Revit.DB import *
from Autodesk.Revit.DB.Architecture import *
from Autodesk.Revit.UI import *

# Import RevitNodes to allow for Dynamo & Revit type conversions
import Revit
clr.ImportExtensions(Revit.Elements)
clr.ImportExtensions(Revit.GeometryConversion)

# Import RevitServices for Document and Transaction management
from RevitServices.Persistence import DocumentManager
from RevitServices.Transactions import TransactionManager

# Add .NET collections import
from System.Collections.Generic import List

# Get the current Revit document from the Document Manager
doc = DocumentManager.Instance.CurrentDBDocument

# Getting the topography with a Filter. At first I tried getting the Toposurface directly and this gave me nothing, so new approach:
topoSurfaces = FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_Topography).ToElements() 

# Get the interior points of the topography surface
interiorPoints=[]
# Get the interior points of the topography surface and delete them
for topoSurface in topoSurfaces:
    pythonList = topoSurface.GetInteriorPoints() # This gets the points as a Python list
    
    # Convert Python list to .NET IList[XYZ]. Realized this method needed an IList. Still not working anyway.
    interiorPoints = List[XYZ](pythonList)
    
    topoEditScope = TopographyEditScope(doc, "Topo")    
    topoEditScope.Start(topoSurface.Id)
    topoSurface.DeletePoints(interiorPoints)
    doc.Regenerate()
    topoEditScope.Commit()

newTopoPoints=topoSurface.GetInteriorPoints()
# Doble checking. Still no points deleted
OUT = pythonList,newTopoPoints, topoSurfaces

```

then I will get “Attempt to modify the model outside of transaction.” The topography edit scope documentation is here [TopographyEditScope Constructor](https://www.revitapidocs.com/2019/0f968149-6567-5e03-7e6e-c1911d4cdf55.htm)

Perhaps the solution would be to attempt to use a transaction group but this is still giving me the same problems.