diff --git a/doc/ReleaseNotes b/doc/ReleaseNotes
index da8e24ae0f..a05c4487e4 100644
--- a/doc/ReleaseNotes
+++ b/doc/ReleaseNotes
@@ -32,6 +32,7 @@ This issue fixes several bugs that were still found in 1.9.2.
 * Fix RAM caching of 2D texture arrays
 * Fix Ctrl+C interrupt propagation to runtime applications
 * Support for InvSphere, Box and Tube solids in bam2egg
+* Preserve "intangible" and "level" collide flags in bam2egg
 * Add normalized() method to vectors
 * asyncFlattenStrong with inPlace=True caused node to disappear
 * Fix asyncFlattenStrong called on nodes without parent
@@ -43,6 +44,7 @@ This issue fixes several bugs that were still found in 1.9.2.
 * Fix exception when creating intervals before ShowBase is started
 * Fix rare X11 .ico cursor bug; also now supports PNG-compressed icons
 * Add keyword argument support to make() methods such as Shader.make()
+* Fix compilation errors with Bullet 2.84
 
 ------------------------  RELEASE 1.9.2  ------------------------
 
diff --git a/panda/src/bullet/bulletCharacterControllerNode.cxx b/panda/src/bullet/bulletCharacterControllerNode.cxx
index 929aaa8001..8d9dfdf434 100644
--- a/panda/src/bullet/bulletCharacterControllerNode.cxx
+++ b/panda/src/bullet/bulletCharacterControllerNode.cxx
@@ -13,6 +13,10 @@
 
 #include "bulletCharacterControllerNode.h"
 
+#if BT_BULLET_VERSION >= 285
+static const btVector3 up_vectors[3] = {btVector3(1.0f, 0.0f, 0.0f), btVector3(0.0f, 1.0f, 0.0f), btVector3(0.0f, 0.0f, 1.0f)};
+#endif
+
 TypeHandle BulletCharacterControllerNode::_type_handle;
 
 /**
@@ -54,8 +58,13 @@ BulletCharacterControllerNode(BulletShape *shape, PN_stdfloat step_height, const
   _angular_movement = 0.0f;
 
   // Character controller
+#if BT_BULLET_VERSION >= 285
+  _character = new btKinematicCharacterController(_ghost, convex, step_height, up_vectors[_up]);
+  _character->setGravity(up_vectors[_up] * -(btScalar)9.81f);
+#else
   _character = new btKinematicCharacterController(_ghost, convex, step_height, _up);
   _character->setGravity((btScalar)9.81f);
+#endif
 
   // Retain a pointer to the shape
   _shape = shape;
@@ -268,8 +277,11 @@ get_max_slope() const {
  */
 PN_stdfloat BulletCharacterControllerNode::
 get_gravity() const {
-
+#if BT_BULLET_VERSION >= 285
+  return -(PN_stdfloat)_character->getGravity()[_up];
+#else
   return (PN_stdfloat)_character->getGravity();
+#endif
 }
 
 /**
@@ -277,8 +289,11 @@ get_gravity() const {
  */
 void BulletCharacterControllerNode::
 set_gravity(PN_stdfloat gravity) {
-
+#if BT_BULLET_VERSION >= 285
+  _character->setGravity(up_vectors[_up] * -(btScalar)gravity);
+#else
   _character->setGravity((btScalar)gravity);
+#endif
 }
 
 
diff --git a/panda/src/bullet/bulletManifoldPoint.I b/panda/src/bullet/bulletManifoldPoint.I
index 0086f3020b..6730d2f349 100644
--- a/panda/src/bullet/bulletManifoldPoint.I
+++ b/panda/src/bullet/bulletManifoldPoint.I
@@ -24,8 +24,15 @@ INLINE BulletManifoldPoint::
  */
 INLINE void BulletManifoldPoint::
 set_lateral_friction_initialized(bool value) {
-
+#if BT_BULLET_VERSION >= 285
+  if (value) {
+    _pt.m_contactPointFlags |= BT_CONTACT_FLAG_LATERAL_FRICTION_INITIALIZED;
+  } else {
+    _pt.m_contactPointFlags &= ~BT_CONTACT_FLAG_LATERAL_FRICTION_INITIALIZED;
+  }
+#else
   _pt.m_lateralFrictionInitialized = value;
+#endif
 }
 
 /**
@@ -33,8 +40,11 @@ set_lateral_friction_initialized(bool value) {
  */
 INLINE bool BulletManifoldPoint::
 get_lateral_friction_initialized() const {
-
+#if BT_BULLET_VERSION >= 285
+  return (_pt.m_contactPointFlags & BT_CONTACT_FLAG_LATERAL_FRICTION_INITIALIZED) != 0;
+#else
   return _pt.m_lateralFrictionInitialized;
+#endif
 }
 
 /**
@@ -195,8 +205,9 @@ get_applied_impulse_lateral2() const {
  */
 INLINE void BulletManifoldPoint::
 set_contact_cfm1(PN_stdfloat value) {
-
+#if BT_BULLET_VERSION < 285
   _pt.m_contactCFM1 = (btScalar)value;
+#endif
 }
 
 /**
@@ -204,8 +215,11 @@ set_contact_cfm1(PN_stdfloat value) {
  */
 INLINE PN_stdfloat BulletManifoldPoint::
 get_contact_cfm1() const {
-
+#if BT_BULLET_VERSION < 285
   return (PN_stdfloat)_pt.m_contactCFM1;
+#else
+  return 0;
+#endif
 }
 
 /**
@@ -213,8 +227,9 @@ get_contact_cfm1() const {
  */
 INLINE void BulletManifoldPoint::
 set_contact_cfm2(PN_stdfloat value) {
-
+#if BT_BULLET_VERSION < 285
   _pt.m_contactCFM2 = (btScalar)value;
+#endif
 }
 
 /**
@@ -222,6 +237,9 @@ set_contact_cfm2(PN_stdfloat value) {
  */
 INLINE PN_stdfloat BulletManifoldPoint::
 get_contact_cfm2() const {
-
+#if BT_BULLET_VERSION < 285
   return (PN_stdfloat)_pt.m_contactCFM2;
+#else
+  return 0;
+#endif
 }
diff --git a/panda/src/egg2pg/eggSaver.cxx b/panda/src/egg2pg/eggSaver.cxx
index bce14af761..fc41f15535 100644
--- a/panda/src/egg2pg/eggSaver.cxx
+++ b/panda/src/egg2pg/eggSaver.cxx
@@ -436,8 +436,20 @@ convert_collision_node(CollisionNode *node, const WorkingNodePath &node_path,
     // traverse solids
     for (int i = 0; i < num_solids; i++) {
       CPT(CollisionSolid) child = node->get_solid(i);
+      int flags = EggGroup::CF_descend;
+
+      if (!child->is_tangible()) {
+        flags |= EggGroup::CF_intangible;
+      }
+
+      if (child->has_effective_normal() &&
+          child->get_effective_normal() == LVector3::up()) {
+        flags |= EggGroup::CF_level;
+      }
+
       if (child->is_of_type(CollisionPolygon::get_class_type())) {
         egg_group->set_cs_type(EggGroup::CST_polyset);
+        egg_group->set_collide_flags(flags);
 
         EggPolygon *egg_poly = new EggPolygon;
         egg_group->add_child(egg_poly);
@@ -463,7 +475,6 @@ convert_collision_node(CollisionNode *node, const WorkingNodePath &node_path,
           egg_sphere = egg_group;
         } else {
           egg_sphere = new EggGroup;
-          egg_sphere->set_collide_flags(EggGroup::CF_descend);
           egg_group->add_child(egg_sphere);
         }
 
@@ -472,6 +483,7 @@ convert_collision_node(CollisionNode *node, const WorkingNodePath &node_path,
         } else {
           egg_sphere->set_cs_type(EggGroup::CST_sphere);
         }
+        egg_sphere->set_collide_flags(flags);
 
         EggVertex ev1, ev2;
         ev1.set_pos(LCAST(double, (center + offset) * net_mat));
@@ -505,10 +517,10 @@ convert_collision_node(CollisionNode *node, const WorkingNodePath &node_path,
           egg_plane = egg_group;
         } else {
           egg_plane = new EggGroup;
-          egg_plane->set_collide_flags(EggGroup::CF_descend);
           egg_group->add_child(egg_plane);
         }
         egg_plane->set_cs_type(EggGroup::CST_plane);
+        egg_plane->set_collide_flags(flags);
 
         EggVertex ev0, ev1, ev2;
         ev0.set_pos(LCAST(double, origin * net_mat));
@@ -532,10 +544,10 @@ convert_collision_node(CollisionNode *node, const WorkingNodePath &node_path,
           egg_box = egg_group;
         } else {
           egg_box = new EggGroup;
-          egg_box->set_collide_flags(EggGroup::CF_descend);
           egg_group->add_child(egg_box);
         }
         egg_box->set_cs_type(EggGroup::CST_box);
+        egg_box->set_collide_flags(flags);
 
         // Just add the min and max points.
         EggVertex ev0, ev1;
@@ -571,10 +583,10 @@ convert_collision_node(CollisionNode *node, const WorkingNodePath &node_path,
           egg_tube = egg_group;
         } else {
           egg_tube = new EggGroup;
-          egg_tube->set_collide_flags(EggGroup::CF_descend);
           egg_group->add_child(egg_tube);
         }
         egg_tube->set_cs_type(EggGroup::CST_tube);
+        egg_tube->set_collide_flags(flags);
 
         // Add two points for the endcaps, and then two points around the
         // centroid to indicate the radius.
diff --git a/pandatool/src/maxegg/maxEggLoader.cxx b/pandatool/src/maxegg/maxEggLoader.cxx
index 222738493e..ba4c705965 100644
--- a/pandatool/src/maxegg/maxEggLoader.cxx
+++ b/pandatool/src/maxegg/maxEggLoader.cxx
@@ -279,7 +279,7 @@ void MaxEggJoint::CreateMaxBone(void)
   _node->SetRenderable(FALSE);
 
 #ifdef _UNICODE
-  TCHAR *wname [1024];
+  TCHAR wname[1024];
   wname[1023] = 0;
   mbstowcs(wname, _egg_joint->get_name().c_str(), 1023);
   _node->SetName(wname);
@@ -452,7 +452,14 @@ MaxEggMesh *MaxEggLoader::GetMesh(EggVertexPool *pool)
     result->_tvert_count = 0;
     result->_cvert_count = 0;
     result->_face_count = 0;
-    result->_node->SetName(TSTR(name.c_str()));
+#ifdef _UNICODE
+    TCHAR wname[1024];
+    wname[1023] = 0;
+    mbstowcs(wname, name.c_str(), 1023);
+    result->_node->SetName(wname);
+#else
+    result->_node->SetName((char*) name.c_str());
+#endif
     _mesh_tab[pool] = result;
   }
   return result;
diff --git a/pandatool/src/maxegg/maxToEggConverter.cxx b/pandatool/src/maxegg/maxToEggConverter.cxx
index f0df22ddca..b07c1fd77d 100644
--- a/pandatool/src/maxegg/maxToEggConverter.cxx
+++ b/pandatool/src/maxegg/maxToEggConverter.cxx
@@ -565,7 +565,14 @@ make_nurbs_curve(INode *max_node, NURBSCVCurve *curve,
         return false;
     }
 
+#ifdef _UNICODE
+    char mbname[1024];
+    mbname[1023] = 0;
+    wcstombs(mbname, max_node->GetName(), 1023);
+    string name(mbname);
+#else
     string name = max_node->GetName();
+#endif
 
     string vpool_name = name + ".cvs";
     EggVertexPool *vpool = new EggVertexPool(vpool_name);
@@ -624,7 +631,15 @@ make_polyset(INode *max_node, Mesh *mesh,
     // separate vertices.  So instead of adding all the vertices up front,
     // we'll start with an empty vpool, and add vertices to it on the fly.
 
+#ifdef _UNICODE
+    char mbname[1024];
+    mbname[1023] = 0;
+    wcstombs(mbname, max_node->GetName(), 1023);
+    string node_name(mbname);
+#else
     string node_name = max_node->GetName();
+#endif
+
     string vpool_name = node_name + ".verts";
     EggVertexPool *vpool = new EggVertexPool(vpool_name);
     egg_group->add_child(vpool);