radiant/csg.cpp

   1 /*
   2    Copyright (C) 1999-2006 Id Software, Inc. and contributors.
   3    For a list of contributors, see the accompanying CONTRIBUTORS file.
   4
   5    This file is part of GtkRadiant.
   6
   7    GtkRadiant is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    GtkRadiant is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with GtkRadiant; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  20  */
  21
  22 #include "csg.h"
  23
  24 #include "debugging/debugging.h"
  25
  26 #include <list>
  27
  28 #include "map.h"
  29 #include "brushmanip.h"
  30 #include "brushnode.h"
  31 #include "grid.h"
  32
  33 void Face_makeBrush( Face& face, const Brush& brush, brush_vector_t& out, float offset ){
  34         if ( face.contributes() ) {
  35                 out.push_back( new Brush( brush ) );
  36                 Face* newFace = out.back()->addFace( face );
  37                 face.getPlane().offset( -offset );
  38                 face.planeChanged();
  39                 if ( newFace != 0 ) {
  40                         newFace->flipWinding();
  41                         newFace->getPlane().offset( offset );
  42                         newFace->planeChanged();
  43                 }
  44         }
  45 }
  46
  47 void Face_extrude( Face& face, const Brush& brush, brush_vector_t& out, float offset ){
  48         if ( face.contributes() ) {
  49                 face.getPlane().offset( offset );
  50                 out.push_back( new Brush( brush ) );
  51                 face.getPlane().offset( -offset );
  52                 Face* newFace = out.back()->addFace( face );
  53                 if ( newFace != 0 ) {
  54                         newFace->flipWinding();
  55                         newFace->planeChanged();
  56                 }
  57         }
  58 }
  59
  60
  61 class FaceMakeBrush
  62 {
  63 const Brush& brush;
  64 brush_vector_t& out;
  65 float offset;
  66 bool room;
  67 public:
  68 FaceMakeBrush( const Brush& brush, brush_vector_t& out, float offset, bool room )
  69         : brush( brush ), out( out ), offset( offset ), room( room ){
  70 }
  71 void operator()( Face& face ) const {
  72         if( room ){
  73                 Face_extrude( face, brush, out, offset );
  74         }
  75         else{
  76                 Face_makeBrush( face, brush, out, offset );
  77         }
  78 }
  79 };
  80
  81 void Brush_makeHollow( const Brush& brush, brush_vector_t& out, float offset, bool room ){
  82         Brush_forEachFace( brush, FaceMakeBrush( brush, out, offset, room ) );
  83 }
  84
  85 class BrushHollowSelectedWalker : public scene::Graph::Walker
  86 {
  87 float m_offset;
  88 bool room;
  89 public:
  90 BrushHollowSelectedWalker( float offset, bool room )
  91         : m_offset( offset ), room( room ){
  92 }
  93 bool pre( const scene::Path& path, scene::Instance& instance ) const {
  94         if ( path.top().get().visible() ) {
  95                 Brush* brush = Node_getBrush( path.top() );
  96                 if ( brush != 0
  97                          && Instance_getSelectable( instance )->isSelected()
  98                          && path.size() > 1 ) {
  99                         brush_vector_t out;
 100                         Brush_makeHollow( *brush, out, m_offset, room );
 101                         for ( brush_vector_t::const_iterator i = out.begin(); i != out.end(); ++i )
 102                         {
 103                                 ( *i )->removeEmptyFaces();
 104                                 NodeSmartReference node( ( new BrushNode() )->node() );
 105                                 Node_getBrush( node )->copy( *( *i ) );
 106                                 delete ( *i );
 107                                 Node_getTraversable( path.parent() )->insert( node );
 108                         }
 109                 }
 110         }
 111         return true;
 112 }
 113 };
 114
 115 typedef std::list<Brush*> brushlist_t;
 116
 117 class BrushGatherSelected : public scene::Graph::Walker
 118 {
 119 brush_vector_t& m_brushlist;
 120 public:
 121 BrushGatherSelected( brush_vector_t& brushlist )
 122         : m_brushlist( brushlist ){
 123 }
 124 bool pre( const scene::Path& path, scene::Instance& instance ) const {
 125         if ( path.top().get().visible() ) {
 126                 Brush* brush = Node_getBrush( path.top() );
 127                 if ( brush != 0
 128                          && Instance_getSelectable( instance )->isSelected() ) {
 129                         m_brushlist.push_back( brush );
 130                 }
 131         }
 132         return true;
 133 }
 134 };
 135
 136 class BrushDeleteSelected : public scene::Graph::Walker
 137 {
 138 public:
 139 bool pre( const scene::Path& path, scene::Instance& instance ) const {
 140         return true;
 141 }
 142 void post( const scene::Path& path, scene::Instance& instance ) const {
 143         if ( path.top().get().visible() ) {
 144                 Brush* brush = Node_getBrush( path.top() );
 145                 if ( brush != 0
 146                          && Instance_getSelectable( instance )->isSelected()
 147                          && path.size() > 1 ) {
 148                         Path_deleteTop( path );
 149                 }
 150         }
 151 }
 152 };
 153
 154 void Scene_BrushMakeHollow_Selected( scene::Graph& graph, bool room ){
 155         GlobalSceneGraph().traverse( BrushHollowSelectedWalker( GetGridSize(), room ) );
 156         GlobalSceneGraph().traverse( BrushDeleteSelected() );
 157 }
 158
 159 /*
 160    =============
 161    CSG_MakeHollow
 162    =============
 163  */
 164
 165 void CSG_MakeHollow( void ){
 166         UndoableCommand undo( "brushHollow" );
 167
 168         Scene_BrushMakeHollow_Selected( GlobalSceneGraph(), false );
 169
 170         SceneChangeNotify();
 171 }
 172
 173 void CSG_MakeRoom( void ){
 174         UndoableCommand undo( "makeRoom" );
 175
 176         Scene_BrushMakeHollow_Selected( GlobalSceneGraph(), true );
 177
 178         SceneChangeNotify();
 179 }
 180
 181 template<typename Type>
 182 class RemoveReference
 183 {
 184 public:
 185 typedef Type type;
 186 };
 187
 188 template<typename Type>
 189 class RemoveReference<Type&>
 190 {
 191 public:
 192 typedef Type type;
 193 };
 194
 195 template<typename Functor>
 196 class Dereference
 197 {
 198 const Functor& functor;
 199 public:
 200 typedef typename RemoveReference<typename Functor::first_argument_type>::type* first_argument_type;
 201 typedef typename Functor::result_type result_type;
 202 Dereference( const Functor& functor ) : functor( functor ){
 203 }
 204 result_type operator()( first_argument_type firstArgument ) const {
 205         return functor( *firstArgument );
 206 }
 207 };
 208
 209 template<typename Functor>
 210 inline Dereference<Functor> makeDereference( const Functor& functor ){
 211         return Dereference<Functor>( functor );
 212 }
 213
 214 typedef Face* FacePointer;
 215 const FacePointer c_nullFacePointer = 0;
 216
 217 template<typename Predicate>
 218 Face* Brush_findIf( const Brush& brush, const Predicate& predicate ){
 219         Brush::const_iterator i = std::find_if( brush.begin(), brush.end(), makeDereference( predicate ) );
 220         return i == brush.end() ? c_nullFacePointer : *i; // uses c_nullFacePointer instead of 0 because otherwise gcc 4.1 attempts conversion to int
 221 }
 222
 223 template<typename Caller>
 224 class BindArguments1
 225 {
 226 typedef typename Caller::second_argument_type FirstBound;
 227 FirstBound firstBound;
 228 public:
 229 typedef typename Caller::result_type result_type;
 230 typedef typename Caller::first_argument_type first_argument_type;
 231 BindArguments1( FirstBound firstBound )
 232         : firstBound( firstBound ){
 233 }
 234 result_type operator()( first_argument_type firstArgument ) const {
 235         return Caller::call( firstArgument, firstBound );
 236 }
 237 };
 238
 239 template<typename Caller>
 240 class BindArguments2
 241 {
 242 typedef typename Caller::second_argument_type FirstBound;
 243 typedef typename Caller::third_argument_type SecondBound;
 244 FirstBound firstBound;
 245 SecondBound secondBound;
 246 public:
 247 typedef typename Caller::result_type result_type;
 248 typedef typename Caller::first_argument_type first_argument_type;
 249 BindArguments2( FirstBound firstBound, SecondBound secondBound )
 250         : firstBound( firstBound ), secondBound( secondBound ){
 251 }
 252 result_type operator()( first_argument_type firstArgument ) const {
 253         return Caller::call( firstArgument, firstBound, secondBound );
 254 }
 255 };
 256
 257 template<typename Caller, typename FirstBound, typename SecondBound>
 258 BindArguments2<Caller> bindArguments( const Caller& caller, FirstBound firstBound, SecondBound secondBound ){
 259         return BindArguments2<Caller>( firstBound, secondBound );
 260 }
 261
 262 inline bool Face_testPlane( const Face& face, const Plane3& plane, bool flipped ){
 263         return face.contributes() && !Winding_TestPlane( face.getWinding(), plane, flipped );
 264 }
 265 typedef Function3<const Face&, const Plane3&, bool, bool, Face_testPlane> FaceTestPlane;
 266
 267
 268
 269 /// \brief Returns true if
 270 /// \li !flipped && brush is BACK or ON
 271 /// \li flipped && brush is FRONT or ON
 272 bool Brush_testPlane( const Brush& brush, const Plane3& plane, bool flipped ){
 273         brush.evaluateBRep();
 274 #if 1
 275         for ( Brush::const_iterator i( brush.begin() ); i != brush.end(); ++i )
 276         {
 277                 if ( Face_testPlane( *( *i ), plane, flipped ) ) {
 278                         return false;
 279                 }
 280         }
 281         return true;
 282 #else
 283         return Brush_findIf( brush, bindArguments( FaceTestPlane(), makeReference( plane ), flipped ) ) == 0;
 284 #endif
 285 }
 286
 287 brushsplit_t Brush_classifyPlane( const Brush& brush, const Plane3& plane ){
 288         brush.evaluateBRep();
 289         brushsplit_t split;
 290         for ( Brush::const_iterator i( brush.begin() ); i != brush.end(); ++i )
 291         {
 292                 if ( ( *i )->contributes() ) {
 293                         split += Winding_ClassifyPlane( ( *i )->getWinding(), plane );
 294                 }
 295         }
 296         return split;
 297 }
 298
 299 bool Brush_subtract( const Brush& brush, const Brush& other, brush_vector_t& ret_fragments ){
 300         if ( aabb_intersects_aabb( brush.localAABB(), other.localAABB() ) ) {
 301                 brush_vector_t fragments;
 302                 fragments.reserve( other.size() );
 303                 Brush back( brush );
 304
 305                 for ( Brush::const_iterator i( other.begin() ); i != other.end(); ++i )
 306                 {
 307                         if ( ( *i )->contributes() ) {
 308                                 brushsplit_t split = Brush_classifyPlane( back, ( *i )->plane3() );
 309                                 if ( split.counts[ePlaneFront] != 0
 310                                          && split.counts[ePlaneBack] != 0 ) {
 311                                         fragments.push_back( new Brush( back ) );
 312                                         Face* newFace = fragments.back()->addFace( *( *i ) );
 313                                         if ( newFace != 0 ) {
 314                                                 newFace->flipWinding();
 315                                         }
 316                                         back.addFace( *( *i ) );
 317                                 }
 318                                 else if ( split.counts[ePlaneBack] == 0 ) {
 319                                         for ( brush_vector_t::iterator i = fragments.begin(); i != fragments.end(); ++i )
 320                                         {
 321                                                 delete( *i );
 322                                         }
 323                                         return false;
 324                                 }
 325                         }
 326                 }
 327                 ret_fragments.insert( ret_fragments.end(), fragments.begin(), fragments.end() );
 328                 return true;
 329         }
 330         return false;
 331 }
 332
 333 class SubtractBrushesFromUnselected : public scene::Graph::Walker
 334 {
 335 const brush_vector_t& m_brushlist;
 336 std::size_t& m_before;
 337 std::size_t& m_after;
 338 public:
 339 SubtractBrushesFromUnselected( const brush_vector_t& brushlist, std::size_t& before, std::size_t& after )
 340         : m_brushlist( brushlist ), m_before( before ), m_after( after ){
 341 }
 342 bool pre( const scene::Path& path, scene::Instance& instance ) const {
 343         return true;
 344 }
 345 void post( const scene::Path& path, scene::Instance& instance ) const {
 346         if ( path.top().get().visible() ) {
 347                 Brush* brush = Node_getBrush( path.top() );
 348                 if ( brush != 0
 349                          && !Instance_getSelectable( instance )->isSelected() ) {
 350                         brush_vector_t buffer[2];
 351                         bool swap = false;
 352                         Brush* original = new Brush( *brush );
 353                         buffer[static_cast<std::size_t>( swap )].push_back( original );
 354
 355                         {
 356                                 for ( brush_vector_t::const_iterator i( m_brushlist.begin() ); i != m_brushlist.end(); ++i )
 357                                 {
 358                                         for ( brush_vector_t::iterator j( buffer[static_cast<std::size_t>( swap )].begin() ); j != buffer[static_cast<std::size_t>( swap )].end(); ++j )
 359                                         {
 360                                                 if ( Brush_subtract( *( *j ), *( *i ), buffer[static_cast<std::size_t>( !swap )] ) ) {
 361                                                         delete ( *j );
 362                                                 }
 363                                                 else
 364                                                 {
 365                                                         buffer[static_cast<std::size_t>( !swap )].push_back( ( *j ) );
 366                                                 }
 367                                         }
 368                                         buffer[static_cast<std::size_t>( swap )].clear();
 369                                         swap = !swap;
 370                                 }
 371                         }
 372
 373                         brush_vector_t& out = buffer[static_cast<std::size_t>( swap )];
 374
 375                         if ( out.size() == 1 && out.back() == original ) {
 376                                 delete original;
 377                         }
 378                         else
 379                         {
 380                                 ++m_before;
 381                                 for ( brush_vector_t::const_iterator i = out.begin(); i != out.end(); ++i )
 382                                 {
 383                                         ++m_after;
 384                                         ( *i )->removeEmptyFaces();
 385                                         if ( !( *i )->empty() ) {
 386                                                 NodeSmartReference node( ( new BrushNode() )->node() );
 387                                                 Node_getBrush( node )->copy( *( *i ) );
 388                                                 delete ( *i );
 389                                                 Node_getTraversable( path.parent() )->insert( node );
 390                                         }
 391                                         else{
 392                                                 delete ( *i );
 393                                         }
 394                                 }
 395                                 Path_deleteTop( path );
 396                         }
 397                 }
 398         }
 399 }
 400 };
 401
 402 void CSG_Subtract(){
 403         brush_vector_t selected_brushes;
 404         GlobalSceneGraph().traverse( BrushGatherSelected( selected_brushes ) );
 405
 406         if ( selected_brushes.empty() ) {
 407                 globalOutputStream() << "CSG Subtract: No brushes selected.\n";
 408         }
 409         else
 410         {
 411                 globalOutputStream() << "CSG Subtract: Subtracting " << Unsigned( selected_brushes.size() ) << " brushes.\n";
 412
 413                 UndoableCommand undo( "brushSubtract" );
 414
 415                 // subtract selected from unselected
 416                 std::size_t before = 0;
 417                 std::size_t after = 0;
 418                 GlobalSceneGraph().traverse( SubtractBrushesFromUnselected( selected_brushes, before, after ) );
 419                 globalOutputStream() << "CSG Subtract: Result: "
 420                                                          << Unsigned( after ) << " fragment" << ( after == 1 ? "" : "s" )
 421                                                          << " from " << Unsigned( before ) << " brush" << ( before == 1 ? "" : "es" ) << ".\n";
 422
 423                 SceneChangeNotify();
 424         }
 425 }
 426
 427 class BrushSplitByPlaneSelected : public scene::Graph::Walker
 428 {
 429 const Vector3& m_p0;
 430 const Vector3& m_p1;
 431 const Vector3& m_p2;
 432 const char* m_shader;
 433 const TextureProjection& m_projection;
 434 EBrushSplit m_split;
 435 public:
 436 BrushSplitByPlaneSelected( const Vector3& p0, const Vector3& p1, const Vector3& p2, const char* shader, const TextureProjection& projection, EBrushSplit split )
 437         : m_p0( p0 ), m_p1( p1 ), m_p2( p2 ), m_shader( shader ), m_projection( projection ), m_split( split ){
 438 }
 439 bool pre( const scene::Path& path, scene::Instance& instance ) const {
 440         return true;
 441 }
 442 void post( const scene::Path& path, scene::Instance& instance ) const {
 443         if ( path.top().get().visible() ) {
 444                 Brush* brush = Node_getBrush( path.top() );
 445                 if ( brush != 0
 446                          && Instance_getSelectable( instance )->isSelected() ) {
 447                         Plane3 plane( plane3_for_points( m_p0, m_p1, m_p2 ) );
 448                         if ( plane3_valid( plane ) ) {
 449                                 brushsplit_t split = Brush_classifyPlane( *brush, m_split == eFront ? plane3_flipped( plane ) : plane );
 450                                 if ( split.counts[ePlaneBack] && split.counts[ePlaneFront] ) {
 451                                         // the plane intersects this brush
 452                                         if ( m_split == eFrontAndBack ) {
 453                                                 NodeSmartReference node( ( new BrushNode() )->node() );
 454                                                 Brush* fragment = Node_getBrush( node );
 455                                                 fragment->copy( *brush );
 456                                                 Face* newFace = fragment->addPlane( m_p0, m_p1, m_p2, m_shader, m_projection );
 457                                                 if ( newFace != 0 && m_split != eFront ) {
 458                                                         newFace->flipWinding();
 459                                                 }
 460                                                 fragment->removeEmptyFaces();
 461                                                 ASSERT_MESSAGE( !fragment->empty(), "brush left with no faces after split" );
 462
 463                                                 Node_getTraversable( path.parent() )->insert( node );
 464                                                 {
 465                                                         scene::Path fragmentPath = path;
 466                                                         fragmentPath.top() = makeReference( node.get() );
 467                                                         selectPath( fragmentPath, true );
 468                                                 }
 469                                         }
 470
 471                                         Face* newFace = brush->addPlane( m_p0, m_p1, m_p2, m_shader, m_projection );
 472                                         if ( newFace != 0 && m_split == eFront ) {
 473                                                 newFace->flipWinding();
 474                                         }
 475                                         brush->removeEmptyFaces();
 476                                         ASSERT_MESSAGE( !brush->empty(), "brush left with no faces after split" );
 477                                 }
 478                                 else
 479                                 // the plane does not intersect this brush
 480                                 if ( m_split != eFrontAndBack && split.counts[ePlaneBack] != 0 ) {
 481                                         // the brush is "behind" the plane
 482                                         Path_deleteTop( path );
 483                                 }
 484                         }
 485                 }
 486         }
 487 }
 488 };
 489
 490 void Scene_BrushSplitByPlane( scene::Graph& graph, const Vector3& p0, const Vector3& p1, const Vector3& p2, const char* shader, EBrushSplit split ){
 491         TextureProjection projection;
 492         TexDef_Construct_Default( projection );
 493         graph.traverse( BrushSplitByPlaneSelected( p0, p1, p2, shader, projection, split ) );
 494         SceneChangeNotify();
 495 }
 496
 497
 498 class BrushInstanceSetClipPlane : public scene::Graph::Walker
 499 {
 500 Plane3 m_plane;
 501 public:
 502 BrushInstanceSetClipPlane( const Plane3& plane )
 503         : m_plane( plane ){
 504 }
 505 bool pre( const scene::Path& path, scene::Instance& instance ) const {
 506         BrushInstance* brush = Instance_getBrush( instance );
 507         if ( brush != 0
 508                  && path.top().get().visible()
 509                  && brush->isSelected() ) {
 510                 BrushInstance& brushInstance = *brush;
 511                 brushInstance.setClipPlane( m_plane );
 512         }
 513         return true;
 514 }
 515 };
 516
 517 void Scene_BrushSetClipPlane( scene::Graph& graph, const Plane3& plane ){
 518         graph.traverse( BrushInstanceSetClipPlane( plane ) );
 519 }
 520
 521 /*
 522    =============
 523    CSG_Merge
 524    =============
 525  */
 526 bool Brush_merge( Brush& brush, const brush_vector_t& in, bool onlyshape ){
 527         // gather potential outer faces
 528
 529         {
 530                 typedef std::vector<const Face*> Faces;
 531                 Faces faces;
 532                 for ( brush_vector_t::const_iterator i( in.begin() ); i != in.end(); ++i )
 533                 {
 534                         ( *i )->evaluateBRep();
 535                         for ( Brush::const_iterator j( ( *i )->begin() ); j != ( *i )->end(); ++j )
 536                         {
 537                                 if ( !( *j )->contributes() ) {
 538                                         continue;
 539                                 }
 540
 541                                 const Face& face1 = *( *j );
 542
 543                                 bool skip = false;
 544                                 // test faces of all input brushes
 545                                 //!\todo SPEEDUP: Flag already-skip faces and only test brushes from i+1 upwards.
 546                                 for ( brush_vector_t::const_iterator k( in.begin() ); !skip && k != in.end(); ++k )
 547                                 {
 548                                         if ( k != i ) { // don't test a brush against itself
 549                                                 for ( Brush::const_iterator l( ( *k )->begin() ); !skip && l != ( *k )->end(); ++l )
 550                                                 {
 551                                                         const Face& face2 = *( *l );
 552
 553                                                         // face opposes another face
 554                                                         if ( plane3_opposing( face1.plane3(), face2.plane3() ) ) {
 555                                                                 // skip opposing planes
 556                                                                 skip  = true;
 557                                                                 break;
 558                                                         }
 559                                                 }
 560                                         }
 561                                 }
 562
 563                                 // check faces already stored
 564                                 for ( Faces::const_iterator m = faces.begin(); !skip && m != faces.end(); ++m )
 565                                 {
 566                                         const Face& face2 = *( *m );
 567
 568                                         // face equals another face
 569                                         if ( plane3_equal( face1.plane3(), face2.plane3() ) ) {
 570                                                 //if the texture/shader references should be the same but are not
 571                                                 if ( !onlyshape && !shader_equal( face1.getShader().getShader(), face2.getShader().getShader() ) ) {
 572                                                         return false;
 573                                                 }
 574                                                 // skip duplicate planes
 575                                                 skip = true;
 576                                                 break;
 577                                         }
 578
 579                                         // face1 plane intersects face2 winding or vice versa
 580                                         if ( Winding_PlanesConcave( face1.getWinding(), face2.getWinding(), face1.plane3(), face2.plane3() ) ) {
 581                                                 // result would not be convex
 582                                                 return false;
 583                                         }
 584                                 }
 585
 586                                 if ( !skip ) {
 587                                         faces.push_back( &face1 );
 588                                 }
 589                         }
 590                 }
 591                 for ( Faces::const_iterator i = faces.begin(); i != faces.end(); ++i )
 592                 {
 593                         if ( !brush.addFace( *( *i ) ) ) {
 594                                 // result would have too many sides
 595                                 return false;
 596                         }
 597                 }
 598         }
 599
 600         brush.removeEmptyFaces();
 601
 602         return true;
 603 }
 604
 605 void CSG_Merge( void ){
 606         brush_vector_t selected_brushes;
 607
 608         // remove selected
 609         GlobalSceneGraph().traverse( BrushGatherSelected( selected_brushes ) );
 610
 611         if ( selected_brushes.empty() ) {
 612                 globalOutputStream() << "CSG Merge: No brushes selected.\n";
 613                 return;
 614         }
 615
 616         if ( selected_brushes.size() < 2 ) {
 617                 globalOutputStream() << "CSG Merge: At least two brushes have to be selected.\n";
 618                 return;
 619         }
 620
 621         globalOutputStream() << "CSG Merge: Merging " << Unsigned( selected_brushes.size() ) << " brushes.\n";
 622
 623         UndoableCommand undo( "brushMerge" );
 624
 625         scene::Path merged_path = GlobalSelectionSystem().ultimateSelected().path();
 626
 627         NodeSmartReference node( ( new BrushNode() )->node() );
 628         Brush* brush = Node_getBrush( node );
 629         // if the new brush would not be convex
 630         if ( !Brush_merge( *brush, selected_brushes, true ) ) {
 631                 globalOutputStream() << "CSG Merge: Failed - result would not be convex.\n";
 632         }
 633         else
 634         {
 635                 ASSERT_MESSAGE( !brush->empty(), "brush left with no faces after merge" );
 636
 637                 // free the original brushes
 638                 GlobalSceneGraph().traverse( BrushDeleteSelected() );
 639
 640                 merged_path.pop();
 641                 Node_getTraversable( merged_path.top() )->insert( node );
 642                 merged_path.push( makeReference( node.get() ) );
 643
 644                 selectPath( merged_path, true );
 645
 646                 globalOutputStream() << "CSG Merge: Succeeded.\n";
 647                 SceneChangeNotify();
 648         }
 649 }