theViewer->GetAllZLayers( anExistingZLayers );
int n = anExistingZLayers.Length();
- myZLayers.resize( n );
- for( int i=1; i<=n; i++ )
- myZLayers[i-1] = anExistingZLayers( i );
+ for( int i=1; i<=n; i++ ) {
+ int aLayerId = anExistingZLayers( i );
+ if ( aLayerId >= 0 ) {
+ myZLayers.push_back( aLayerId );
+ }
+ }
myIndex = 0;
}