diff --git a/panda/src/glstuff/glGraphicsStateGuardian_src.cxx b/panda/src/glstuff/glGraphicsStateGuardian_src.cxx
index da61634c6d..3e08ae7e8b 100644
--- a/panda/src/glstuff/glGraphicsStateGuardian_src.cxx
+++ b/panda/src/glstuff/glGraphicsStateGuardian_src.cxx
@@ -2348,7 +2348,10 @@ release_geom(GeomContext *gc) {
 ////////////////////////////////////////////////////////////////////
 DataContext *CLP(GraphicsStateGuardian)::
 prepare_data(qpGeomVertexArrayData *data) {
-  cerr << "prepare_data\n";
+  if (GLCAT.is_debug()) {
+    GLCAT.debug()
+      << "prepare_data(" << (void *)data << ")\n";
+  }
 
   if (_supports_buffers) {
     CLP(DataContext) *gdc = new CLP(DataContext)(data);
@@ -2375,7 +2378,10 @@ prepare_data(qpGeomVertexArrayData *data) {
 ////////////////////////////////////////////////////////////////////
 void CLP(GraphicsStateGuardian)::
 apply_data(DataContext *dc) {
-  cerr << "apply_data\n";
+  if (GLCAT.is_debug()) {
+    GLCAT.debug()
+      << "apply_data(" << (void *)dc->_data << ")\n";
+  }
 
   nassertv(_supports_buffers);
 
@@ -2404,7 +2410,10 @@ apply_data(DataContext *dc) {
 ////////////////////////////////////////////////////////////////////
 void CLP(GraphicsStateGuardian)::
 release_data(DataContext *dc) {
-  cerr << "release_data\n";
+  if (GLCAT.is_debug()) {
+    GLCAT.debug()
+      << "release_data(" << (void *)dc->_data << ")\n";
+  }
 
   nassertv(_supports_buffers);
   
diff --git a/panda/src/gobj/qpgeomVertexData.I b/panda/src/gobj/qpgeomVertexData.I
index 8ebc1f3c78..febe7a2bb4 100644
--- a/panda/src/gobj/qpgeomVertexData.I
+++ b/panda/src/gobj/qpgeomVertexData.I
@@ -28,6 +28,23 @@ get_format() const {
   return _format;
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: qpGeomVertexData::get_usage_hint
+//       Access: Published
+//  Description: Returns the usage hint that was passed to the
+//               constructor, and which will be passed to each array
+//               data object created initially.  However, each
+//               individual array may be replaced with a different
+//               array object with an independent usage hint
+//               specified.
+//
+//               See GeomVertexArrayData::get_usage_hint().
+////////////////////////////////////////////////////////////////////
+INLINE qpGeomVertexArrayData::UsageHint qpGeomVertexData::
+get_usage_hint() const {
+  return _usage_hint;
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: qpGeomVertexData::set_num_vertices
 //       Access: Published
diff --git a/panda/src/gobj/qpgeomVertexData.cxx b/panda/src/gobj/qpgeomVertexData.cxx
index 184b9cf4bf..151ab820c5 100644
--- a/panda/src/gobj/qpgeomVertexData.cxx
+++ b/panda/src/gobj/qpgeomVertexData.cxx
@@ -45,7 +45,8 @@ qpGeomVertexData() {
 qpGeomVertexData::
 qpGeomVertexData(const qpGeomVertexFormat *format,
                  qpGeomVertexArrayData::UsageHint usage_hint) :
-  _format(format)
+  _format(format),
+  _usage_hint(usage_hint)
 {
   nassertv(_format->is_registered());
 
@@ -263,7 +264,7 @@ convert_to(const qpGeomVertexFormat *new_format) const {
   PStatTimer timer(_munge_data_pcollector);
 
   PT(qpGeomVertexData) new_data = 
-    new qpGeomVertexData(new_format, qpGeomVertexArrayData::UH_client);
+    new qpGeomVertexData(new_format, get_usage_hint());
 
   pset<int> done_arrays;
 
@@ -299,7 +300,7 @@ convert_to(const qpGeomVertexFormat *new_format) const {
 
   // Now go back through and copy any data that's left over.
   for (i = 0; i < num_arrays; ++i) {
-    CPTA_uchar data = get_array(i)->get_data();
+    CPTA_uchar array_data = get_array(i)->get_data();
     const qpGeomVertexArrayFormat *array_format = _format->get_array(i);
     int num_data_types = array_format->get_num_data_types();
     for (int di = 0; di < num_data_types; ++di) {
@@ -308,10 +309,8 @@ convert_to(const qpGeomVertexFormat *new_format) const {
       int new_i = new_format->get_array_with(data_type->get_name());
       if (new_i >= 0 && done_arrays.count(new_i) == 0) {
         // The data type exists in the new format; we have to copy it.
-        PT(qpGeomVertexArrayData) new_array_data = new
-          qpGeomVertexArrayData(*get_array(i));
-        new_data->set_array(new_i, new_array_data);
-        PTA_uchar new_data = new_array_data->modify_data();
+        PTA_uchar new_array_data = 
+          new_data->modify_array(new_i)->modify_data();
 
         const qpGeomVertexArrayFormat *new_array_format = 
           new_format->get_array(new_i);
@@ -319,9 +318,9 @@ convert_to(const qpGeomVertexFormat *new_format) const {
           new_array_format->get_data_type(data_type->get_name());
 
         new_data_type->copy_records
-          (new_data + new_data_type->get_start(), 
+          (new_array_data + new_data_type->get_start(), 
            new_array_format->get_stride(),
-           data + data_type->get_start(), array_format->get_stride(),
+           array_data + data_type->get_start(), array_format->get_stride(),
            data_type, num_vertices);
       }
     }
diff --git a/panda/src/gobj/qpgeomVertexData.h b/panda/src/gobj/qpgeomVertexData.h
index f1a568ce2c..66c8a01e01 100644
--- a/panda/src/gobj/qpgeomVertexData.h
+++ b/panda/src/gobj/qpgeomVertexData.h
@@ -69,6 +69,7 @@ PUBLISHED:
   virtual ~qpGeomVertexData();
 
   INLINE const qpGeomVertexFormat *get_format() const;
+  INLINE qpGeomVertexArrayData::UsageHint get_usage_hint() const;
 
   int get_num_vertices() const;
   INLINE bool set_num_vertices(int n);
@@ -112,6 +113,7 @@ private:
 
 private:
   CPT(qpGeomVertexFormat) _format;
+  qpGeomVertexArrayData::UsageHint _usage_hint;
 
   typedef pvector< PT(qpGeomVertexArrayData) > Arrays;