How To: Create a TIN from a 3D FeatureClass Using ArcObjects

Summary

Developers frequently want to convert data from one format to another. This example illustrates how to convert from a 3D FeatureClass to a TIN.

Procedure

This Visual Basic for Applications code sample assumes the first layer in the active DataFrame is 3D Points. See Related Information below for the link to ArcObjects Online; refer to it for descriptions of the input to the AddFromFeatureClass method on ITinEdit.

Code:
Dim pMxDoc As IMxDocument 
Set pMxDoc = ThisDocument 

' Assume the first layer in the map is 3D points. 
Dim pFLayer As IFeatureLayer 
Set pFLayer = pMxDoc.ActiveView.FocusMap.Layer(0) 

Dim pFClass As IFeatureClass 
Set pFClass = pFLayer.FeatureClass 

Dim pFields As IFields 
Set pFields = pFClass.Fields 

' Heights for TIN will come from shape geometry. 
' Height field is therefore 'Shape' field. Use an alternate field 
' if heights come from numeric attribute rather than geometry. 
Dim pHeightField As IField 
Set pHeightField = pFields.Field(pFields.FindField(pFClass.ShapeFieldName)) 

Dim pGDS As IGeoDataset 
Set pGDS = pFClass 

Dim pEnv As IEnvelope 
Set pEnv = pGDS.Extent 
Set pEnv.SpatialReference = pGDS.SpatialReference 

Dim pTinEdit As ITinEdit 
Set pTinEdit = New Tin 

' If the envelope used has its spatial ref set (as it does in this 
' example), the output TIN will use it. 
pTinEdit.InitNew pEnv 

pTinEdit.AddFromFeatureClass pFClass, Nothing, pHeightField, Nothing, esriTinMassPoint 

pTinEdit.SaveAs "c:\temp\test_tin" 
pTinEdit.StopEditing False 

Dim pTLayer As ITinLayer 
Set pTLayer = New TinLayer 
Set pTLayer.Dataset = pTinEdit 

Dim pLayer As ILayer 
Set pLayer = pTLayer 

pLayer.Name = "tin" 

' Add the resulting TIN as a layer to the map. 
pMxDoc.ActiveView.FocusMap.AddLayer pTLayer