Added texture format into Traits.

include/osg/GraphicsContext

@@ -71,6 +71,7 @@ class OSG_EXPORT GraphicsContext : public Object
                 quadBufferStereo(false),
                 doubleBuffer(false),
                 target(0),
+                format(0),
                 level(0),
                 face(0),
                 mipMapGeneration(false),
@@ -110,6 +111,7 @@ class OSG_EXPORT GraphicsContext : public Object
 
             // render to texture
             GLenum          target;
+            GLenum          format;
             unsigned int    level;
             unsigned int    face;
             unsigned int    mipMapGeneration;

src/osgUtil/RenderStage.cpp

@@ -504,6 +504,7 @@ void RenderStage::runCameraSetUp(osg::RenderInfo& renderInfo)
                         if (renderTargetImplemntation==osg::Camera::PIXEL_BUFFER_RTT)
                         {
                             traits->target = attachment._texture.valid() ? attachment._texture->getTextureTarget() : 0;
+                            traits->format = bufferFormat;
                             traits->level = level;
                             traits->face = face;
                             traits->mipMapGeneration = attachment._mipMapGeneration;