/*************************************************************************/ /* csg.cpp */ /*************************************************************************/ /* This file is part of: */ /* GODOT ENGINE */ /* https://godotengine.org */ /*************************************************************************/ /* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur. */ /* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md). */ /* */ /* Permission is hereby granted, free of charge, to any person obtaining */ /* a copy of this software and associated documentation files (the */ /* "Software"), to deal in the Software without restriction, including */ /* without limitation the rights to use, copy, modify, merge, publish, */ /* distribute, sublicense, and/or sell copies of the Software, and to */ /* permit persons to whom the Software is furnished to do so, subject to */ /* the following conditions: */ /* */ /* The above copyright notice and this permission notice shall be */ /* included in all copies or substantial portions of the Software. */ /* */ /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */ /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */ /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/ /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */ /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */ /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */ /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ /*************************************************************************/ #include "csg.h" #include "core/math/geometry.h" #include "core/math/math_funcs.h" #include "core/sort_array.h" // Static helper functions. inline static bool is_snapable(const Vector3 &p_point1, const Vector3 &p_point2, real_t p_distance) { return (p_point1 - p_point2).length_squared() < p_distance * p_distance; } inline static Vector2 interpolate_segment_uv(const Vector2 p_segement_points[2], const Vector2 p_uvs[2], const Vector2 &p_interpolation_point) { float segment_length = (p_segement_points[1] - p_segement_points[0]).length(); if (segment_length < CMP_EPSILON) return p_uvs[0]; float distance = (p_interpolation_point - p_segement_points[0]).length(); float fraction = distance / segment_length; return p_uvs[0].linear_interpolate(p_uvs[1], fraction); } inline static Vector2 interpolate_triangle_uv(const Vector2 p_vertices[3], const Vector2 p_uvs[3], const Vector2 &p_interpolation_point) { if (p_interpolation_point.distance_squared_to(p_vertices[0]) < CMP_EPSILON2) return p_uvs[0]; if (p_interpolation_point.distance_squared_to(p_vertices[1]) < CMP_EPSILON2) return p_uvs[1]; if (p_interpolation_point.distance_squared_to(p_vertices[2]) < CMP_EPSILON2) return p_uvs[2]; Vector2 edge1 = p_vertices[1] - p_vertices[0]; Vector2 edge2 = p_vertices[2] - p_vertices[0]; Vector2 interpolation = p_interpolation_point - p_vertices[0]; float edge1_on_edge1 = edge1.dot(edge1); float edge1_on_edge2 = edge1.dot(edge2); float edge2_on_edge2 = edge2.dot(edge2); float inter_on_edge1 = interpolation.dot(edge1); float inter_on_edge2 = interpolation.dot(edge2); float scale = (edge1_on_edge1 * edge2_on_edge2 - edge1_on_edge2 * edge1_on_edge2); if (scale == 0) return p_uvs[0]; float v = (edge2_on_edge2 * inter_on_edge1 - edge1_on_edge2 * inter_on_edge2) / scale; float w = (edge1_on_edge1 * inter_on_edge2 - edge1_on_edge2 * inter_on_edge1) / scale; float u = 1.0f - v - w; return p_uvs[0] * u + p_uvs[1] * v + p_uvs[2] * w; } static inline bool ray_intersects_triangle(const Vector3 &p_from, const Vector3 &p_dir, const Vector3 p_vertices[3], float p_tolerance, Vector3 &r_intersection_point) { Vector3 edge1 = p_vertices[1] - p_vertices[0]; Vector3 edge2 = p_vertices[2] - p_vertices[0]; Vector3 h = p_dir.cross(edge2); real_t a = edge1.dot(h); // Check if ray is parrallel to triangle. if (Math::is_zero_approx(a)) return false; real_t f = 1.0 / a; Vector3 s = p_from - p_vertices[0]; real_t u = f * s.dot(h); if (u < 0.0 - p_tolerance || u > 1.0 + p_tolerance) return false; Vector3 q = s.cross(edge1); real_t v = f * p_dir.dot(q); if (v < 0.0 - p_tolerance || u + v > 1.0 + p_tolerance) return false; // Ray intersects triangle. // Calculate distance. real_t t = f * edge2.dot(q); // Confirm triangle is in front of ray. if (t >= p_tolerance) { r_intersection_point = p_from + p_dir * t; return true; } else return false; } inline bool is_point_in_triangle(const Vector3 &p_point, const Vector3 p_vertices[3], int p_shifted = 0) { real_t det = p_vertices[0].dot(p_vertices[1].cross(p_vertices[2])); // If determinant is, zero try shift the triangle and the point. if (Math::is_zero_approx(det)) { if (p_shifted > 2) { // Triangle appears degenerate, so ignore it. return false; } Vector3 shift_by; shift_by[p_shifted] = 1; Vector3 shifted_point = p_point + shift_by; Vector3 shifted_vertices[3] = { p_vertices[0] + shift_by, p_vertices[1] + shift_by, p_vertices[2] + shift_by }; return is_point_in_triangle(shifted_point, shifted_vertices, p_shifted + 1); } // Find the barycentric coordinates of the point with respect to the vertices. real_t lambda[3]; lambda[0] = p_vertices[1].cross(p_vertices[2]).dot(p_point) / det; lambda[1] = p_vertices[2].cross(p_vertices[0]).dot(p_point) / det; lambda[2] = p_vertices[0].cross(p_vertices[1]).dot(p_point) / det; // Point is in the plane if all lambdas sum to 1. if (!Math::is_equal_approx(lambda[0] + lambda[1] + lambda[2], 1)) return false; // Point is inside the triangle if all lambdas are positive. if (lambda[0] < 0 || lambda[1] < 0 || lambda[2] < 0) return false; return true; } inline static bool are_segements_parallel(const Vector2 p_segment1_points[2], const Vector2 p_segment2_points[2], float p_vertex_snap2) { Vector2 segment1 = p_segment1_points[1] - p_segment1_points[0]; Vector2 segment2 = p_segment2_points[1] - p_segment2_points[0]; real_t segment1_length2 = segment1.dot(segment1); real_t segment2_length2 = segment2.dot(segment2); real_t segment_onto_segment = segment2.dot(segment1); if (segment1_length2 < p_vertex_snap2 || segment2_length2 < p_vertex_snap2) return true; real_t max_separation2; if (segment1_length2 > segment2_length2) { max_separation2 = segment2_length2 - segment_onto_segment * segment_onto_segment / segment1_length2; } else { max_separation2 = segment1_length2 - segment_onto_segment * segment_onto_segment / segment2_length2; } return max_separation2 < p_vertex_snap2; } // CSGBrush void CSGBrush::_regen_face_aabbs() { for (int i = 0; i < faces.size(); i++) { faces.write[i].aabb = AABB(); faces.write[i].aabb.position = faces[i].vertices[0]; faces.write[i].aabb.expand_to(faces[i].vertices[1]); faces.write[i].aabb.expand_to(faces[i].vertices[2]); } } void CSGBrush::build_from_faces(const PoolVector &p_vertices, const PoolVector &p_uvs, const PoolVector &p_smooth, const PoolVector > &p_materials, const PoolVector &p_invert_faces) { faces.clear(); int vc = p_vertices.size(); ERR_FAIL_COND((vc % 3) != 0); PoolVector::Read rv = p_vertices.read(); int uvc = p_uvs.size(); PoolVector::Read ruv = p_uvs.read(); int sc = p_smooth.size(); PoolVector::Read rs = p_smooth.read(); int mc = p_materials.size(); PoolVector >::Read rm = p_materials.read(); int ic = p_invert_faces.size(); PoolVector::Read ri = p_invert_faces.read(); Map, int> material_map; faces.resize(p_vertices.size() / 3); for (int i = 0; i < faces.size(); i++) { Face &f = faces.write[i]; f.vertices[0] = rv[i * 3 + 0]; f.vertices[1] = rv[i * 3 + 1]; f.vertices[2] = rv[i * 3 + 2]; if (uvc == vc) { f.uvs[0] = ruv[i * 3 + 0]; f.uvs[1] = ruv[i * 3 + 1]; f.uvs[2] = ruv[i * 3 + 2]; } if (sc == vc / 3) f.smooth = rs[i]; else f.smooth = false; if (ic == vc / 3) f.invert = ri[i]; else f.invert = false; if (mc == vc / 3) { Ref mat = rm[i]; if (mat.is_valid()) { const Map, int>::Element *E = material_map.find(mat); if (E) { f.material = E->get(); } else { f.material = material_map.size(); material_map[mat] = f.material; } } else { f.material = -1; } } } materials.resize(material_map.size()); for (Map, int>::Element *E = material_map.front(); E; E = E->next()) { materials.write[E->get()] = E->key(); } _regen_face_aabbs(); } void CSGBrush::copy_from(const CSGBrush &p_brush, const Transform &p_xform) { faces = p_brush.faces; materials = p_brush.materials; for (int i = 0; i < faces.size(); i++) { for (int j = 0; j < 3; j++) { faces.write[i].vertices[j] = p_xform.xform(p_brush.faces[i].vertices[j]); } } _regen_face_aabbs(); } // CSGBrushOperation void CSGBrushOperation::merge_brushes(Operation p_operation, const CSGBrush &p_brush_a, const CSGBrush &p_brush_b, CSGBrush &r_merged_brush, float p_vertex_snap) { // Check for face collisions and add necessary faces. Build2DFaceCollection build2DFaceCollection; for (int i = 0; i < p_brush_a.faces.size(); i++) { for (int j = 0; j < p_brush_b.faces.size(); j++) { if (p_brush_a.faces[i].aabb.intersects_inclusive(p_brush_b.faces[j].aabb)) { update_faces(p_brush_a, i, p_brush_b, j, build2DFaceCollection, p_vertex_snap); } } } // Add faces to MeshMerge. MeshMerge mesh_merge; mesh_merge.vertex_snap = p_vertex_snap; for (int i = 0; i < p_brush_a.faces.size(); i++) { Ref material; if (p_brush_a.faces[i].material != -1) { material = p_brush_a.materials[p_brush_a.faces[i].material]; } if (build2DFaceCollection.build2DFacesA.has(i)) { build2DFaceCollection.build2DFacesA[i].addFacesToMesh(mesh_merge, p_brush_a.faces[i].smooth, p_brush_a.faces[i].invert, material, false); } else { Vector3 points[3]; Vector2 uvs[3]; for (int j = 0; j < 3; j++) { points[j] = p_brush_a.faces[i].vertices[j]; uvs[j] = p_brush_a.faces[i].uvs[j]; } mesh_merge.add_face(points, uvs, p_brush_a.faces[i].smooth, p_brush_a.faces[i].invert, material, false); } } for (int i = 0; i < p_brush_b.faces.size(); i++) { Ref material; if (p_brush_b.faces[i].material != -1) { material = p_brush_b.materials[p_brush_b.faces[i].material]; } if (build2DFaceCollection.build2DFacesB.has(i)) { build2DFaceCollection.build2DFacesB[i].addFacesToMesh(mesh_merge, p_brush_b.faces[i].smooth, p_brush_b.faces[i].invert, material, true); } else { Vector3 points[3]; Vector2 uvs[3]; for (int j = 0; j < 3; j++) { points[j] = p_brush_b.faces[i].vertices[j]; uvs[j] = p_brush_b.faces[i].uvs[j]; } mesh_merge.add_face(points, uvs, p_brush_b.faces[i].smooth, p_brush_b.faces[i].invert, material, true); } } // Mark faces that ended up inside the intersection. mesh_merge.mark_inside_faces(); // Create new brush and fill with new faces. r_merged_brush.faces.clear(); switch (p_operation) { case OPERATION_UNION: { int outside_count = 0; for (int i = 0; i < mesh_merge.faces.size(); i++) { if (mesh_merge.faces[i].inside) continue; outside_count++; } r_merged_brush.faces.resize(outside_count); outside_count = 0; for (int i = 0; i < mesh_merge.faces.size(); i++) { if (mesh_merge.faces[i].inside) continue; for (int j = 0; j < 3; j++) { r_merged_brush.faces.write[outside_count].vertices[j] = mesh_merge.points[mesh_merge.faces[i].points[j]]; r_merged_brush.faces.write[outside_count].uvs[j] = mesh_merge.faces[i].uvs[j]; } r_merged_brush.faces.write[outside_count].smooth = mesh_merge.faces[i].smooth; r_merged_brush.faces.write[outside_count].invert = mesh_merge.faces[i].invert; r_merged_brush.faces.write[outside_count].material = mesh_merge.faces[i].material_idx; outside_count++; } r_merged_brush._regen_face_aabbs(); } break; case OPERATION_INTERSECTION: { int inside_count = 0; for (int i = 0; i < mesh_merge.faces.size(); i++) { if (!mesh_merge.faces[i].inside) continue; inside_count++; } r_merged_brush.faces.resize(inside_count); inside_count = 0; for (int i = 0; i < mesh_merge.faces.size(); i++) { if (!mesh_merge.faces[i].inside) continue; for (int j = 0; j < 3; j++) { r_merged_brush.faces.write[inside_count].vertices[j] = mesh_merge.points[mesh_merge.faces[i].points[j]]; r_merged_brush.faces.write[inside_count].uvs[j] = mesh_merge.faces[i].uvs[j]; } r_merged_brush.faces.write[inside_count].smooth = mesh_merge.faces[i].smooth; r_merged_brush.faces.write[inside_count].invert = mesh_merge.faces[i].invert; r_merged_brush.faces.write[inside_count].material = mesh_merge.faces[i].material_idx; inside_count++; } r_merged_brush._regen_face_aabbs(); } break; case OPERATION_SUBSTRACTION: { int face_count = 0; for (int i = 0; i < mesh_merge.faces.size(); i++) { if (mesh_merge.faces[i].from_b && !mesh_merge.faces[i].inside) continue; if (!mesh_merge.faces[i].from_b && mesh_merge.faces[i].inside) continue; face_count++; } r_merged_brush.faces.resize(face_count); face_count = 0; for (int i = 0; i < mesh_merge.faces.size(); i++) { if (mesh_merge.faces[i].from_b && !mesh_merge.faces[i].inside) continue; if (!mesh_merge.faces[i].from_b && mesh_merge.faces[i].inside) continue; for (int j = 0; j < 3; j++) { r_merged_brush.faces.write[face_count].vertices[j] = mesh_merge.points[mesh_merge.faces[i].points[j]]; r_merged_brush.faces.write[face_count].uvs[j] = mesh_merge.faces[i].uvs[j]; } if (mesh_merge.faces[i].from_b) { //invert facing of insides of B SWAP(r_merged_brush.faces.write[face_count].vertices[1], r_merged_brush.faces.write[face_count].vertices[2]); SWAP(r_merged_brush.faces.write[face_count].uvs[1], r_merged_brush.faces.write[face_count].uvs[2]); } r_merged_brush.faces.write[face_count].smooth = mesh_merge.faces[i].smooth; r_merged_brush.faces.write[face_count].invert = mesh_merge.faces[i].invert; r_merged_brush.faces.write[face_count].material = mesh_merge.faces[i].material_idx; face_count++; } r_merged_brush._regen_face_aabbs(); } break; } // Update the list of materials. r_merged_brush.materials.resize(mesh_merge.materials.size()); for (const Map, int>::Element *E = mesh_merge.materials.front(); E; E = E->next()) { r_merged_brush.materials.write[E->get()] = E->key(); } } // CSGBrushOperation::MeshMerge // Use a limit to speed up bvh and limit the depth. #define BVH_LIMIT 8 int CSGBrushOperation::MeshMerge::_create_bvh(FaceBVH *facebvhptr, FaceBVH **facebvhptrptr, int p_from, int p_size, int p_depth, int &r_max_depth, int &r_max_alloc) { if (p_depth > r_max_depth) { r_max_depth = p_depth; } if (p_size == 0) { return -1; } if (p_size <= BVH_LIMIT) { for (int i = 0; i < p_size - 1; i++) { facebvhptrptr[p_from + i]->next = facebvhptrptr[p_from + i + 1] - facebvhptr; } return facebvhptrptr[p_from] - facebvhptr; } AABB aabb; aabb = facebvhptrptr[p_from]->aabb; for (int i = 1; i < p_size; i++) { aabb.merge_with(facebvhptrptr[p_from + i]->aabb); } int li = aabb.get_longest_axis_index(); switch (li) { case Vector3::AXIS_X: { SortArray sort_x; sort_x.nth_element(0, p_size, p_size / 2, &facebvhptrptr[p_from]); //sort_x.sort(&p_bb[p_from],p_size); } break; case Vector3::AXIS_Y: { SortArray sort_y; sort_y.nth_element(0, p_size, p_size / 2, &facebvhptrptr[p_from]); //sort_y.sort(&p_bb[p_from],p_size); } break; case Vector3::AXIS_Z: { SortArray sort_z; sort_z.nth_element(0, p_size, p_size / 2, &facebvhptrptr[p_from]); //sort_z.sort(&p_bb[p_from],p_size); } break; } int left = _create_bvh(facebvhptr, facebvhptrptr, p_from, p_size / 2, p_depth + 1, r_max_depth, r_max_alloc); int right = _create_bvh(facebvhptr, facebvhptrptr, p_from + p_size / 2, p_size - p_size / 2, p_depth + 1, r_max_depth, r_max_alloc); int index = r_max_alloc++; FaceBVH *_new = &facebvhptr[index]; _new->aabb = aabb; _new->center = aabb.position + aabb.size * 0.5; _new->face = -1; _new->left = left; _new->right = right; _new->next = -1; return index; } void CSGBrushOperation::MeshMerge::_add_distance(List &r_intersectionsA, List &r_intersectionsB, bool p_from_B, real_t p_distance) const { List &intersections = p_from_B ? r_intersectionsB : r_intersectionsA; // Check if distance exists. for (const List::Element *E = intersections.front(); E; E = E->next()) if (Math::is_equal_approx(**E, p_distance)) return; intersections.push_back(p_distance); } bool CSGBrushOperation::MeshMerge::_bvh_inside(FaceBVH *facebvhptr, int p_max_depth, int p_bvh_first, int p_face_idx) const { Face face = faces[p_face_idx]; Vector3 face_points[3] = { points[face.points[0]], points[face.points[1]], points[face.points[2]] }; Vector3 face_center = (face_points[0] + face_points[1] + face_points[2]) / 3.0; Vector3 face_normal = Plane(face_points[0], face_points[1], face_points[2]).normal; uint32_t *stack = (uint32_t *)alloca(sizeof(int) * p_max_depth); enum { TEST_AABB_BIT = 0, VISIT_LEFT_BIT = 1, VISIT_RIGHT_BIT = 2, VISIT_DONE_BIT = 3, VISITED_BIT_SHIFT = 29, NODE_IDX_MASK = (1 << VISITED_BIT_SHIFT) - 1, VISITED_BIT_MASK = ~NODE_IDX_MASK }; List intersectionsA; List intersectionsB; int level = 0; int pos = p_bvh_first; stack[0] = pos; while (true) { uint32_t node = stack[level] & NODE_IDX_MASK; const FaceBVH *current_facebvhptr = &(facebvhptr[node]); bool done = false; switch (stack[level] >> VISITED_BIT_SHIFT) { case TEST_AABB_BIT: { if (current_facebvhptr->face >= 0) { while (current_facebvhptr) { if (p_face_idx != current_facebvhptr->face && current_facebvhptr->aabb.intersects_ray(face_center, face_normal)) { const Face ¤t_face = faces[current_facebvhptr->face]; Vector3 current_points[3] = { points[current_face.points[0]], points[current_face.points[1]], points[current_face.points[2]] }; Vector3 current_normal = Plane(current_points[0], current_points[1], current_points[2]).normal; Vector3 intersection_point; // Check if faces are co-planar. if ((current_normal - face_normal).length_squared() < CMP_EPSILON2 && is_point_in_triangle(face_center, current_points)) { // Only add an intersection if checking a B face. if (face.from_b) _add_distance(intersectionsA, intersectionsB, current_face.from_b, 0); } else if (ray_intersects_triangle(face_center, face_normal, current_points, CMP_EPSILON, intersection_point)) { real_t distance = (intersection_point - face_center).length(); _add_distance(intersectionsA, intersectionsB, current_face.from_b, distance); } } if (current_facebvhptr->next != -1) { current_facebvhptr = &facebvhptr[current_facebvhptr->next]; } else { current_facebvhptr = nullptr; } } stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node; } else { bool valid = current_facebvhptr->aabb.intersects_ray(face_center, face_normal); if (!valid) { stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node; } else { stack[level] = (VISIT_LEFT_BIT << VISITED_BIT_SHIFT) | node; } } continue; } case VISIT_LEFT_BIT: { stack[level] = (VISIT_RIGHT_BIT << VISITED_BIT_SHIFT) | node; stack[level + 1] = current_facebvhptr->left | TEST_AABB_BIT; level++; continue; } case VISIT_RIGHT_BIT: { stack[level] = (VISIT_DONE_BIT << VISITED_BIT_SHIFT) | node; stack[level + 1] = current_facebvhptr->right | TEST_AABB_BIT; level++; continue; } case VISIT_DONE_BIT: { if (level == 0) { done = true; break; } else level--; continue; } } if (done) break; } // Inside if face normal intersects other faces an odd number of times. return (intersectionsA.size() + intersectionsB.size()) & 1; } void CSGBrushOperation::MeshMerge::mark_inside_faces() { // Mark faces that are inside. This helps later do the boolean ops when merging. // This approach is very brute force with a bunch of optimizations, // such as BVH and pre AABB intersection test. Vector bvhvec; bvhvec.resize(faces.size() * 3); // Will never be larger than this (TODO: Make better) FaceBVH *facebvh = bvhvec.ptrw(); AABB aabb_a; AABB aabb_b; bool first_a = true; bool first_b = true; for (int i = 0; i < faces.size(); i++) { facebvh[i].left = -1; facebvh[i].right = -1; facebvh[i].face = i; facebvh[i].aabb.position = points[faces[i].points[0]]; facebvh[i].aabb.expand_to(points[faces[i].points[1]]); facebvh[i].aabb.expand_to(points[faces[i].points[2]]); facebvh[i].center = facebvh[i].aabb.position + facebvh[i].aabb.size * 0.5; facebvh[i].aabb.grow_by(vertex_snap); facebvh[i].next = -1; if (faces[i].from_b) { if (first_b) { aabb_b = facebvh[i].aabb; first_b = false; } else { aabb_b.merge_with(facebvh[i].aabb); } } else { if (first_a) { aabb_a = facebvh[i].aabb; first_a = false; } else { aabb_a.merge_with(facebvh[i].aabb); } } } AABB intersection_aabb = aabb_a.intersection(aabb_b); // Check if shape AABBs intersect. if (intersection_aabb.size == Vector3()) return; Vector bvhtrvec; bvhtrvec.resize(faces.size()); FaceBVH **bvhptr = bvhtrvec.ptrw(); for (int i = 0; i < faces.size(); i++) { bvhptr[i] = &facebvh[i]; } int max_depth = 0; int max_alloc = faces.size(); _create_bvh(facebvh, bvhptr, 0, faces.size(), 1, max_depth, max_alloc); for (int i = 0; i < faces.size(); i++) { // Check if face AABB intersects the intersection AABB. if (!intersection_aabb.intersects_inclusive(facebvh[i].aabb)) continue; if (_bvh_inside(facebvh, max_depth, max_alloc - 1, i)) faces.write[i].inside = true; } } void CSGBrushOperation::MeshMerge::add_face(const Vector3 p_points[], const Vector2 p_uvs[], bool p_smooth, bool p_invert, const Ref &p_material, bool p_from_b) { int indices[3]; for (int i = 0; i < 3; i++) { VertexKey vk; vk.x = int((double(p_points[i].x) + double(vertex_snap) * 0.31234) / double(vertex_snap)); vk.y = int((double(p_points[i].y) + double(vertex_snap) * 0.31234) / double(vertex_snap)); vk.z = int((double(p_points[i].z) + double(vertex_snap) * 0.31234) / double(vertex_snap)); int res; if (snap_cache.lookup(vk, res)) { indices[i] = res; } else { indices[i] = points.size(); points.push_back(p_points[i]); snap_cache.set(vk, indices[i]); } } // Don't add degenerate faces. if (indices[0] == indices[2] || indices[0] == indices[1] || indices[1] == indices[2]) return; MeshMerge::Face face; face.from_b = p_from_b; face.inside = false; face.smooth = p_smooth; face.invert = p_invert; if (p_material.is_valid()) { if (!materials.has(p_material)) { face.material_idx = materials.size(); materials[p_material] = face.material_idx; } else { face.material_idx = materials[p_material]; } } else { face.material_idx = -1; } for (int k = 0; k < 3; k++) { face.points[k] = indices[k]; face.uvs[k] = p_uvs[k]; } faces.push_back(face); } // CSGBrushOperation::Build2DFaces int CSGBrushOperation::Build2DFaces::_get_point_idx(const Vector2 &p_point) { for (int vertex_idx = 0; vertex_idx < vertices.size(); ++vertex_idx) { if ((p_point - vertices[vertex_idx].point).length_squared() < vertex_snap2) return vertex_idx; } return -1; } int CSGBrushOperation::Build2DFaces::_add_vertex(const Vertex2D &p_vertex) { // Check if vertex exists. int vertex_id = _get_point_idx(p_vertex.point); if (vertex_id != -1) return vertex_id; vertices.push_back(p_vertex); return vertices.size() - 1; } void CSGBrushOperation::Build2DFaces::_add_vertex_idx_sorted(Vector &r_vertex_indices, int p_new_vertex_index) { if (p_new_vertex_index >= 0 && r_vertex_indices.find(p_new_vertex_index) == -1) { ERR_FAIL_COND_MSG(p_new_vertex_index >= vertices.size(), "Invalid vertex index."); // The first vertex. if (r_vertex_indices.size() == 0) { // Simply add it. r_vertex_indices.push_back(p_new_vertex_index); return; } // The second vertex. if (r_vertex_indices.size() == 1) { Vector2 first_point = vertices[r_vertex_indices[0]].point; Vector2 new_point = vertices[p_new_vertex_index].point; // Sort along the axis with the greatest difference. int axis = 0; if (Math::abs(new_point.x - first_point.x) < Math::abs(new_point.y - first_point.y)) axis = 1; // Add it to the beginnig or the end appropriately. if (new_point[axis] < first_point[axis]) r_vertex_indices.insert(0, p_new_vertex_index); else r_vertex_indices.push_back(p_new_vertex_index); return; } // Third or later vertices. Vector2 first_point = vertices[r_vertex_indices[0]].point; Vector2 last_point = vertices[r_vertex_indices[r_vertex_indices.size() - 1]].point; Vector2 new_point = vertices[p_new_vertex_index].point; // Determine axis being sorted against i.e. the axis with the greatest difference. int axis = 0; if (Math::abs(last_point.x - first_point.x) < Math::abs(last_point.y - first_point.y)) axis = 1; // Insert the point at the appropriate index. for (int insert_idx = 0; insert_idx < r_vertex_indices.size(); ++insert_idx) { Vector2 insert_point = vertices[r_vertex_indices[insert_idx]].point; if (new_point[axis] < insert_point[axis]) { r_vertex_indices.insert(insert_idx, p_new_vertex_index); return; } } // New largest, add it to the end. r_vertex_indices.push_back(p_new_vertex_index); } } void CSGBrushOperation::Build2DFaces::_merge_faces(const Vector &p_segment_indices) { int segments = p_segment_indices.size() - 1; if (segments < 2) return; // Faces around an inner vertex are merged by moving the inner vertex to the first vertex. for (int sorted_idx = 1; sorted_idx < segments; ++sorted_idx) { int closest_idx = 0; int inner_idx = p_segment_indices[sorted_idx]; if (sorted_idx > segments / 2) { // Merge to other segment end. closest_idx = segments; // Reverse the merge order. inner_idx = p_segment_indices[segments + segments / 2 - sorted_idx]; } // Find the mergable faces. Vector merge_faces_idx; Vector merge_faces; Vector merge_faces_inner_vertex_idx; for (int face_idx = 0; face_idx < faces.size(); ++face_idx) { for (int face_vertex_idx = 0; face_vertex_idx < 3; ++face_vertex_idx) { if (faces[face_idx].vertex_idx[face_vertex_idx] == inner_idx) { merge_faces_idx.push_back(face_idx); merge_faces.push_back(faces[face_idx]); merge_faces_inner_vertex_idx.push_back(face_vertex_idx); } } } Vector degenerate_points; // Create the new faces. for (int merge_idx = 0; merge_idx < merge_faces.size(); ++merge_idx) { int outer_edge_idx[2]; outer_edge_idx[0] = merge_faces[merge_idx].vertex_idx[(merge_faces_inner_vertex_idx[merge_idx] + 1) % 3]; outer_edge_idx[1] = merge_faces[merge_idx].vertex_idx[(merge_faces_inner_vertex_idx[merge_idx] + 2) % 3]; // Skip flattened faces. if (outer_edge_idx[0] == p_segment_indices[closest_idx] || outer_edge_idx[1] == p_segment_indices[closest_idx]) continue; //Don't create degenerate triangles. Vector2 edge1[2] = { vertices[outer_edge_idx[0]].point, vertices[p_segment_indices[closest_idx]].point }; Vector2 edge2[2] = { vertices[outer_edge_idx[1]].point, vertices[p_segment_indices[closest_idx]].point }; if (are_segements_parallel(edge1, edge2, vertex_snap2)) { if (!degenerate_points.find(outer_edge_idx[0])) degenerate_points.push_back(outer_edge_idx[0]); if (!degenerate_points.find(outer_edge_idx[1])) degenerate_points.push_back(outer_edge_idx[1]); continue; } // Create new faces. Face2D new_face; new_face.vertex_idx[0] = p_segment_indices[closest_idx]; new_face.vertex_idx[1] = outer_edge_idx[0]; new_face.vertex_idx[2] = outer_edge_idx[1]; faces.push_back(new_face); } // Delete the old faces in reverse index order. merge_faces_idx.sort(); merge_faces_idx.invert(); for (int i = 0; i < merge_faces_idx.size(); ++i) faces.remove(merge_faces_idx[i]); if (degenerate_points.size() == 0) continue; // Split faces using degenerate points. for (int face_idx = 0; face_idx < faces.size(); ++face_idx) { Face2D face = faces[face_idx]; Vertex2D face_vertices[3] = { vertices[face.vertex_idx[0]], vertices[face.vertex_idx[1]], vertices[face.vertex_idx[2]] }; Vector2 face_points[3] = { face_vertices[0].point, face_vertices[1].point, face_vertices[2].point }; for (int point_idx = 0; point_idx < degenerate_points.size(); ++point_idx) { int degenerate_idx = degenerate_points[point_idx]; Vector2 point_2D = vertices[degenerate_idx].point; // Check if point is existing face vertex. bool existing = false; for (int i = 0; i < 3; ++i) { if ((point_2D - face_vertices[i].point).length_squared() < vertex_snap2) { existing = true; break; } } if (existing) continue; // Check if point is on an each edge. for (int face_edge_idx = 0; face_edge_idx < 3; ++face_edge_idx) { Vector2 edge_points[2] = { face_points[face_edge_idx], face_points[(face_edge_idx + 1) % 3] }; Vector2 closest_point = Geometry::get_closest_point_to_segment_2d(point_2D, edge_points); if ((closest_point - point_2D).length_squared() < vertex_snap2) { int opposite_vertex_idx = face.vertex_idx[(face_edge_idx + 2) % 3]; // If new vertex snaps to degenerate vertex, just delete this face. if (degenerate_idx == opposite_vertex_idx) { faces.remove(face_idx); // Update index. --face_idx; break; } // Create two new faces around the new edge and remove this face. // The new edge is the last edge. Face2D left_face; left_face.vertex_idx[0] = degenerate_idx; left_face.vertex_idx[1] = face.vertex_idx[(face_edge_idx + 1) % 3]; left_face.vertex_idx[2] = opposite_vertex_idx; Face2D right_face; right_face.vertex_idx[0] = opposite_vertex_idx; right_face.vertex_idx[1] = face.vertex_idx[face_edge_idx]; right_face.vertex_idx[2] = degenerate_idx; faces.remove(face_idx); faces.insert(face_idx, right_face); faces.insert(face_idx, left_face); // Don't check against the new faces. ++face_idx; // No need to check other edges. break; } } } } } } void CSGBrushOperation::Build2DFaces::_find_edge_intersections(const Vector2 p_segment_points[2], Vector &r_segment_indices) { // For each face. for (int face_idx = 0; face_idx < faces.size(); ++face_idx) { Face2D face = faces[face_idx]; Vertex2D face_vertices[3] = { vertices[face.vertex_idx[0]], vertices[face.vertex_idx[1]], vertices[face.vertex_idx[2]] }; // Check each edge. for (int face_edge_idx = 0; face_edge_idx < 3; ++face_edge_idx) { Vector2 edge_points[2] = { face_vertices[face_edge_idx].point, face_vertices[(face_edge_idx + 1) % 3].point }; Vector2 edge_uvs[2] = { face_vertices[face_edge_idx].uv, face_vertices[(face_edge_idx + 1) % 3].uv }; Vector2 intersection_point; // First check if the ends of the segment are on the edge. bool on_edge = false; for (int edge_point_idx = 0; edge_point_idx < 2; ++edge_point_idx) { intersection_point = Geometry::get_closest_point_to_segment_2d(p_segment_points[edge_point_idx], edge_points); if ((intersection_point - p_segment_points[edge_point_idx]).length_squared() < vertex_snap2) { on_edge = true; break; } } // Else check if the segment intersects the edge. if (on_edge || Geometry::segment_intersects_segment_2d(p_segment_points[0], p_segment_points[1], edge_points[0], edge_points[1], &intersection_point)) { // Check if intersection point is an edge point. if ((intersection_point - edge_points[0]).length_squared() < vertex_snap2 || (intersection_point - edge_points[1]).length_squared() < vertex_snap2) continue; // Check if edge exists, by checking if the intersecting segment is parallel to the edge. if (are_segements_parallel(p_segment_points, edge_points, vertex_snap2)) continue; // Add the intersection point as a new vertex. Vertex2D new_vertex; new_vertex.point = intersection_point; new_vertex.uv = interpolate_segment_uv(edge_points, edge_uvs, intersection_point); int new_vertex_idx = _add_vertex(new_vertex); int opposite_vertex_idx = face.vertex_idx[(face_edge_idx + 2) % 3]; _add_vertex_idx_sorted(r_segment_indices, new_vertex_idx); // If new vertex snaps to opposite vertex, just delete this face. if (new_vertex_idx == opposite_vertex_idx) { faces.remove(face_idx); // Update index. --face_idx; break; } // If opposite point is on the segemnt, add its index to segment indices too. Vector2 closest_point = Geometry::get_closest_point_to_segment_2d(vertices[opposite_vertex_idx].point, p_segment_points); if ((closest_point - vertices[opposite_vertex_idx].point).length_squared() < vertex_snap2) _add_vertex_idx_sorted(r_segment_indices, opposite_vertex_idx); // Create two new faces around the new edge and remove this face. // The new edge is the last edge. Face2D left_face; left_face.vertex_idx[0] = new_vertex_idx; left_face.vertex_idx[1] = face.vertex_idx[(face_edge_idx + 1) % 3]; left_face.vertex_idx[2] = opposite_vertex_idx; Face2D right_face; right_face.vertex_idx[0] = opposite_vertex_idx; right_face.vertex_idx[1] = face.vertex_idx[face_edge_idx]; right_face.vertex_idx[2] = new_vertex_idx; faces.remove(face_idx); faces.insert(face_idx, right_face); faces.insert(face_idx, left_face); // Check against the new faces. --face_idx; break; } } } } int CSGBrushOperation::Build2DFaces::_insert_point(const Vector2 &p_point) { int new_vertex_idx = -1; for (int face_idx = 0; face_idx < faces.size(); ++face_idx) { Face2D face = faces[face_idx]; Vertex2D face_vertices[3] = { vertices[face.vertex_idx[0]], vertices[face.vertex_idx[1]], vertices[face.vertex_idx[2]] }; Vector2 points[3] = { face_vertices[0].point, face_vertices[1].point, face_vertices[2].point }; Vector2 uvs[3] = { face_vertices[0].uv, face_vertices[1].uv, face_vertices[2].uv }; // Check if point is existing face vertex. for (int i = 0; i < 3; ++i) { if ((p_point - face_vertices[i].point).length_squared() < vertex_snap2) return face.vertex_idx[i]; } // Check if point is on an each edge. bool on_edge = false; for (int face_edge_idx = 0; face_edge_idx < 3; ++face_edge_idx) { Vector2 edge_points[2] = { points[face_edge_idx], points[(face_edge_idx + 1) % 3] }; Vector2 edge_uvs[2] = { uvs[face_edge_idx], uvs[(face_edge_idx + 1) % 3] }; Vector2 closest_point = Geometry::get_closest_point_to_segment_2d(p_point, edge_points); if ((closest_point - p_point).length_squared() < vertex_snap2) { on_edge = true; // Add the point as a new vertex. Vertex2D new_vertex; new_vertex.point = p_point; new_vertex.uv = interpolate_segment_uv(edge_points, edge_uvs, p_point); new_vertex_idx = _add_vertex(new_vertex); int opposite_vertex_idx = face.vertex_idx[(face_edge_idx + 2) % 3]; // If new vertex snaps to opposite vertex, just delete this face. if (new_vertex_idx == opposite_vertex_idx) { faces.remove(face_idx); // Update index. --face_idx; break; } // Don't create degenerate triangles. Vector2 split_edge1[2] = { vertices[new_vertex_idx].point, edge_points[0] }; Vector2 split_edge2[2] = { vertices[new_vertex_idx].point, edge_points[1] }; Vector2 new_edge[2] = { vertices[new_vertex_idx].point, vertices[opposite_vertex_idx].point }; if (are_segements_parallel(split_edge1, new_edge, vertex_snap2) && are_segements_parallel(split_edge2, new_edge, vertex_snap2)) { break; } // Create two new faces around the new edge and remove this face. // The new edge is the last edge. Face2D left_face; left_face.vertex_idx[0] = new_vertex_idx; left_face.vertex_idx[1] = face.vertex_idx[(face_edge_idx + 1) % 3]; left_face.vertex_idx[2] = opposite_vertex_idx; Face2D right_face; right_face.vertex_idx[0] = opposite_vertex_idx; right_face.vertex_idx[1] = face.vertex_idx[face_edge_idx]; right_face.vertex_idx[2] = new_vertex_idx; faces.remove(face_idx); faces.insert(face_idx, right_face); faces.insert(face_idx, left_face); // Don't check against the new faces. ++face_idx; // No need to check other edges. break; } } // If not on an edge, check if the point is inside the face. if (!on_edge && Geometry::is_point_in_triangle(p_point, face_vertices[0].point, face_vertices[1].point, face_vertices[2].point)) { // Add the point as a new vertex. Vertex2D new_vertex; new_vertex.point = p_point; new_vertex.uv = interpolate_triangle_uv(points, uvs, p_point); new_vertex_idx = _add_vertex(new_vertex); // Create three new faces around this point and remove this face. // The new vertex is the last vertex. for (int i = 0; i < 3; ++i) { // Don't create degenerate triangles. Vector2 edge[2] = { points[i], points[(i + 1) % 3] }; Vector2 new_edge1[2] = { vertices[new_vertex_idx].point, points[i] }; Vector2 new_edge2[2] = { vertices[new_vertex_idx].point, points[(i + 1) % 3] }; if (are_segements_parallel(edge, new_edge1, vertex_snap2) && are_segements_parallel(edge, new_edge2, vertex_snap2)) { continue; } Face2D new_face; new_face.vertex_idx[0] = face.vertex_idx[i]; new_face.vertex_idx[1] = face.vertex_idx[(i + 1) % 3]; new_face.vertex_idx[2] = new_vertex_idx; faces.push_back(new_face); } faces.remove(face_idx); // No need to check other faces. break; } } return new_vertex_idx; } void CSGBrushOperation::Build2DFaces::insert(const CSGBrush &p_brush, int p_face_idx) { // Find edge points that cross the plane and face points that are in the plane. // Map those points to 2D. // Create new faces from those points. Vector2 points_2D[3]; int points_count = 0; for (int i = 0; i < 3; i++) { Vector3 point_3D = p_brush.faces[p_face_idx].vertices[i]; if (plane.has_point(point_3D)) { // Point is in the plane, add it. Vector3 point_2D = plane.project(point_3D); point_2D = to_2D.xform(point_2D); points_2D[points_count++] = Vector2(point_2D.x, point_2D.y); } else { Vector3 next_point_3D = p_brush.faces[p_face_idx].vertices[(i + 1) % 3]; if (plane.has_point(next_point_3D)) continue; // Next point is in plane, it will be added separately. if (plane.is_point_over(point_3D) == plane.is_point_over(next_point_3D)) continue; // Both points on the same side of the plane, ignore. // Edge crosses the plane, find and add the intersection point. Vector3 point_2D; if (plane.intersects_segment(point_3D, next_point_3D, &point_2D)) { point_2D = to_2D.xform(point_2D); points_2D[points_count++] = Vector2(point_2D.x, point_2D.y); } } } Vector segment_indices; Vector2 segment[2]; int inserted_index[3] = { -1, -1, -1 }; // Insert points. for (int i = 0; i < points_count; ++i) { inserted_index[i] = _insert_point(points_2D[i]); } if (points_count == 2) { // Insert a single segment. segment[0] = points_2D[0]; segment[1] = points_2D[1]; _find_edge_intersections(segment, segment_indices); for (int i = 0; i < 2; ++i) { _add_vertex_idx_sorted(segment_indices, inserted_index[i]); } _merge_faces(segment_indices); } if (points_count == 3) { // Insert three segments. for (int edge_idx = 0; edge_idx < 3; ++edge_idx) { segment[0] = points_2D[edge_idx]; segment[1] = points_2D[(edge_idx + 1) % 3]; _find_edge_intersections(segment, segment_indices); for (int i = 0; i < 2; ++i) { _add_vertex_idx_sorted(segment_indices, inserted_index[(edge_idx + i) % 3]); } _merge_faces(segment_indices); segment_indices.clear(); } } } void CSGBrushOperation::Build2DFaces::addFacesToMesh(MeshMerge &r_mesh_merge, bool p_smooth, bool p_invert, const Ref &p_material, bool p_from_b) { for (int face_idx = 0; face_idx < faces.size(); ++face_idx) { Face2D face = faces[face_idx]; Vertex2D fv[3] = { vertices[face.vertex_idx[0]], vertices[face.vertex_idx[1]], vertices[face.vertex_idx[2]] }; // Convert 2D vertex points to 3D. Vector3 points_3D[3]; Vector2 uvs[3]; for (int i = 0; i < 3; ++i) { Vector3 point_2D(fv[i].point.x, fv[i].point.y, 0); points_3D[i] = to_3D.xform(point_2D); uvs[i] = fv[i].uv; } r_mesh_merge.add_face(points_3D, uvs, p_smooth, p_invert, p_material, p_from_b); } } CSGBrushOperation::Build2DFaces::Build2DFaces(const CSGBrush &p_brush, int p_face_idx, float p_vertex_snap2) : vertex_snap2(p_vertex_snap2 * p_vertex_snap2) { // Convert 3D vertex points to 2D. Vector3 points_3D[3] = { p_brush.faces[p_face_idx].vertices[0], p_brush.faces[p_face_idx].vertices[1], p_brush.faces[p_face_idx].vertices[2], }; plane = Plane(points_3D[0], points_3D[1], points_3D[2]); to_3D.origin = points_3D[0]; to_3D.basis.set_axis(2, plane.normal); to_3D.basis.set_axis(0, (points_3D[1] - points_3D[2]).normalized()); to_3D.basis.set_axis(1, to_3D.basis.get_axis(0).cross(to_3D.basis.get_axis(2)).normalized()); to_2D = to_3D.affine_inverse(); Face2D face; for (int i = 0; i < 3; i++) { Vertex2D vertex; Vector3 point_2D = to_2D.xform(points_3D[i]); vertex.point.x = point_2D.x; vertex.point.y = point_2D.y; vertex.uv = p_brush.faces[p_face_idx].uvs[i]; vertices.push_back(vertex); face.vertex_idx[i] = i; } faces.push_back(face); } void CSGBrushOperation::update_faces(const CSGBrush &p_brush_a, const int p_face_idx_a, const CSGBrush &p_brush_b, const int p_face_idx_b, Build2DFaceCollection &p_collection, float p_vertex_snap) { Vector3 vertices_a[3] = { p_brush_a.faces[p_face_idx_a].vertices[0], p_brush_a.faces[p_face_idx_a].vertices[1], p_brush_a.faces[p_face_idx_a].vertices[2], }; Vector3 vertices_b[3] = { p_brush_b.faces[p_face_idx_b].vertices[0], p_brush_b.faces[p_face_idx_b].vertices[1], p_brush_b.faces[p_face_idx_b].vertices[2], }; // Don't use degenerate faces. bool has_degenerate = false; if (is_snapable(vertices_a[0], vertices_a[1], p_vertex_snap) || is_snapable(vertices_a[0], vertices_a[2], p_vertex_snap) || is_snapable(vertices_a[1], vertices_a[2], p_vertex_snap)) { p_collection.build2DFacesA[p_face_idx_a] = Build2DFaces(); has_degenerate = true; } if (is_snapable(vertices_b[0], vertices_b[1], p_vertex_snap) || is_snapable(vertices_b[0], vertices_b[2], p_vertex_snap) || is_snapable(vertices_b[1], vertices_b[2], p_vertex_snap)) { p_collection.build2DFacesB[p_face_idx_b] = Build2DFaces(); has_degenerate = true; } if (has_degenerate) return; // Ensure B has points either side of or in the plane of A. int in_plane_count = 0, over_count = 0, under_count = 0; Plane plane_a(vertices_a[0], vertices_a[1], vertices_a[2]); ERR_FAIL_COND_MSG(plane_a.normal == Vector3(), "Couldn't form plane from Brush A face."); for (int i = 0; i < 3; i++) { if (plane_a.has_point(vertices_b[i])) in_plane_count++; else if (plane_a.is_point_over(vertices_b[i])) over_count++; else under_count++; } // If all points under or over the plane, there is no intesection. if (over_count == 3 || under_count == 3) return; // Ensure A has points either side of or in the plane of B. in_plane_count = 0; over_count = 0; under_count = 0; Plane plane_b(vertices_b[0], vertices_b[1], vertices_b[2]); ERR_FAIL_COND_MSG(plane_b.normal == Vector3(), "Couldn't form plane from Brush B face."); for (int i = 0; i < 3; i++) { if (plane_b.has_point(vertices_a[i])) in_plane_count++; else if (plane_b.is_point_over(vertices_a[i])) over_count++; else under_count++; } // If all points under or over the plane, there is no intesection. if (over_count == 3 || under_count == 3) return; // Check for intersection using the SAT theorem. { // Edge pair cross product combinations. for (int i = 0; i < 3; i++) { Vector3 axis_a = (vertices_a[i] - vertices_a[(i + 1) % 3]).normalized(); for (int j = 0; j < 3; j++) { Vector3 axis_b = (vertices_b[j] - vertices_b[(j + 1) % 3]).normalized(); Vector3 sep_axis = axis_a.cross(axis_b); if (sep_axis == Vector3()) continue; //colineal sep_axis.normalize(); real_t min_a = 1e20, max_a = -1e20; real_t min_b = 1e20, max_b = -1e20; for (int k = 0; k < 3; k++) { real_t d = sep_axis.dot(vertices_a[k]); min_a = MIN(min_a, d); max_a = MAX(max_a, d); d = sep_axis.dot(vertices_b[k]); min_b = MIN(min_b, d); max_b = MAX(max_b, d); } min_b -= (max_a - min_a) * 0.5; max_b += (max_a - min_a) * 0.5; real_t dmin = min_b - (min_a + max_a) * 0.5; real_t dmax = max_b - (min_a + max_a) * 0.5; if (dmin > CMP_EPSILON || dmax < -CMP_EPSILON) { return; // Does not contain zero, so they don't overlap. } } } } // If we're still here, the faces probably intersect, so add new faces. if (!p_collection.build2DFacesA.has(p_face_idx_a)) { p_collection.build2DFacesA[p_face_idx_a] = Build2DFaces(p_brush_a, p_face_idx_a, p_vertex_snap); } p_collection.build2DFacesA[p_face_idx_a].insert(p_brush_b, p_face_idx_b); if (!p_collection.build2DFacesB.has(p_face_idx_b)) { p_collection.build2DFacesB[p_face_idx_b] = Build2DFaces(p_brush_b, p_face_idx_b, p_vertex_snap); } p_collection.build2DFacesB[p_face_idx_b].insert(p_brush_a, p_face_idx_a); }