From 62d1e7ac644a17e38cbd2e116f0fad63a7673da3 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Mon, 27 Jun 2016 11:33:55 +0100
Subject: [PATCH] Restructed the cast

---
 src/osgPlugins/ac/ac3d.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/osgPlugins/ac/ac3d.cpp b/src/osgPlugins/ac/ac3d.cpp
index acca77b46..bea9384a9 100644
--- a/src/osgPlugins/ac/ac3d.cpp
+++ b/src/osgPlugins/ac/ac3d.cpp
@@ -167,9 +167,10 @@ class ReaderWriterAC : public osgDB::ReaderWriter
         virtual WriteResult writeNode(const osg::Node& node,std::ostream& fout, const Options* opts) const
         {
             // write ac file.
-            if(dynamic_cast<const osg::Group*>(&node))
+
+            const osg::Group *gp=node.asGroup();
+            if(gp)
             {
-                const osg::Group *gp=dynamic_cast<const osg::Group*>(&node);
                 const unsigned int nch=gp->getNumChildren();
                 for (unsigned int i=0; i<nch; i++)
                 {