Fix compile past last simgear change.

diff --git a/src/Main/viewer.cxx b/src/Main/viewer.cxx
index 49d77cf5b0c30c25249b2ac99a5ef4db18300bfa..97ae345190c78903f1dd6f70827c29e861ace1df 100644 (file)
--- a/src/Main/viewer.cxx
+++ b/src/Main/viewer.cxx
@@ -35,6 +35,7 @@
 #include <simgear/debug/logstream.hxx>
 #include <simgear/constants.h>
 #include <simgear/scene/model/placement.hxx>
+#include <simgear/scene/util/OsgMath.hxx>
 
 #include <Main/globals.hxx>
 #include <Scenery/scenery.hxx>