diff --git a/EGkVolZmap.h b/EGkVolZmap.h
index d7e645e..cf3a679 100644
--- a/EGkVolZmap.h
+++ b/EGkVolZmap.h
@@ -89,6 +89,7 @@ class __declspec( novtable) IVolZmap : public IGeoObj
       virtual bool GetPartBBox( int nPart, const Frame3d& frRef, BBox3d& b3Ref, int nFlag = BBF_STANDARD) const = 0 ;
       virtual IVolZmap* ClonePart( int nPart) const = 0 ;
       virtual bool RemovePart( int nPart) = 0 ;
+      virtual int  GetPartMinDistFromPoint( const Point3d& ptP) const = 0 ;
 } ;
 
 //-----------------------------------------------------------------------------
diff --git a/EXeExecutor.h b/EXeExecutor.h
index 00c223f..3df5d2e 100644
--- a/EXeExecutor.h
+++ b/EXeExecutor.h
@@ -615,6 +615,7 @@ EXE_EXPORT int  ExeExtractSurfBezierLoops( int nId, int nDestGrpId, int* pnCount
 EXE_EXPORT bool ExeVolZmapVolume( int nId, double& dVol) ;
 EXE_EXPORT int  ExeVolZmapPartCount( int nId) ;
 EXE_EXPORT bool ExeVolZmapPartVolume( int nId, int nPart, double& dVol) ;
+EXE_EXPORT bool ExeVolZmapGetPartMinDist( int nId, const Point3d ptNear, int nRefType, int& nPart) ;
 
 // Geo Snap Vector/Point/Frame
 EXE_EXPORT bool ExeStartPoint( int nId, int nRefId, Point3d& ptP) ;