backport #40670

qgis · Dec 19, 2020 · 38b13718e14b5d0d92e67e5f50cdb0d83ce3a50e · 38b1371
1 parent c2d0231
commit 38b13718e14b5d0d92e67e5f50cdb0d83ce3a50e
Unified Split

Showing with 10 additions and 4 deletions.

+10 −4 src/analysis/interpolation/qgstininterpolator.cpp
diff --git a/src/analysis/interpolation/qgstininterpolator.cpp b/src/analysis/interpolation/qgstininterpolator.cpp
@@ -294,14 +294,20 @@ int QgsTinInterpolator::insertData( const QgsFeature &f, QgsInterpolator::ValueS
               switch ( source )
               {
                 case ValueAttribute:
-                  point.setZ( attributeValue );
+                  if ( point.is3D() )
+                    point.setZ( attributeValue );
+                  else
+                    point.addZValue( attributeValue );
                   break;
 
-                case ValueZ:
+                case ValueM:
+                  if ( point.is3D() )
+                    point.setZ( point.m() );
+                  else
+                    point.addZValue( point.m() );
                   break;
 
-                case ValueM:
-                  point.setZ( point.m() );
+                case ValueZ:
                   break;
               }
             }