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Diffstat (limited to 'source/blender/blenkernel/intern/bvhutils.c')
| -rw-r--r-- | source/blender/blenkernel/intern/bvhutils.c | 426 |
1 files changed, 426 insertions, 0 deletions
diff --git a/source/blender/blenkernel/intern/bvhutils.c b/source/blender/blenkernel/intern/bvhutils.c new file mode 100644 index 00000000000..5b68a637ea2 --- /dev/null +++ b/source/blender/blenkernel/intern/bvhutils.c @@ -0,0 +1,426 @@ +/** + * + * $Id$ + * + * ***** BEGIN GPL LICENSE BLOCK ***** + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * The Original Code is Copyright (C) Blender Foundation. + * All rights reserved. + * + * The Original Code is: all of this file. + * + * Contributor(s): André Pinto. + * + * ***** END GPL LICENSE BLOCK ***** + */ +#include <stdio.h> +#include <string.h> +#include <math.h> + +#include "BKE_bvhutils.h" + +#include "DNA_object_types.h" +#include "DNA_modifier_types.h" +#include "DNA_meshdata_types.h" + +#include "BKE_DerivedMesh.h" +#include "BKE_utildefines.h" +#include "BKE_deform.h" +#include "BKE_cdderivedmesh.h" +#include "BKE_displist.h" +#include "BKE_global.h" + +#include "BLI_arithb.h" + +/* Math stuff for ray casting on mesh faces and for nearest surface */ + +static float nearest_point_in_tri_surface(const float *point, const float *v0, const float *v1, const float *v2, float *nearest); + +#define ISECT_EPSILON 1e-6 +static float ray_tri_intersection(const BVHTreeRay *ray, const float m_dist, const float *v0, const float *v1, const float *v2) +{ + float dist; + + if(RayIntersectsTriangle(ray->origin, ray->direction, v0, v1, v2, &dist, NULL)) + return dist; + + return FLT_MAX; +} + +static float sphereray_tri_intersection(const BVHTreeRay *ray, float radius, const float m_dist, const float *v0, const float *v1, const float *v2) +{ + + float idist; + float p1[3]; + float plane_normal[3], hit_point[3]; + + CalcNormFloat((float*)v0, (float*)v1, (float*)v2, plane_normal); + + VECADDFAC( p1, ray->origin, ray->direction, m_dist); + if(SweepingSphereIntersectsTriangleUV(ray->origin, p1, radius, v0, v1, v2, &idist, &hit_point)) + { + return idist * m_dist; + } + + return FLT_MAX; +} + +/* + * This calculates the distance from point to the plane + * Distance is negative if point is on the back side of plane + */ +static float point_plane_distance(const float *point, const float *plane_point, const float *plane_normal) +{ + float pp[3]; + VECSUB(pp, point, plane_point); + return INPR(pp, plane_normal); +} +static float choose_nearest(const float v0[2], const float v1[2], const float point[2], float closest[2]) +{ + float d[2][2], sdist[2]; + VECSUB2D(d[0], v0, point); + VECSUB2D(d[1], v1, point); + + sdist[0] = d[0][0]*d[0][0] + d[0][1]*d[0][1]; + sdist[1] = d[1][0]*d[1][0] + d[1][1]*d[1][1]; + + if(sdist[0] < sdist[1]) + { + if(closest) + VECCOPY2D(closest, v0); + return sdist[0]; + } + else + { + if(closest) + VECCOPY2D(closest, v1); + return sdist[1]; + } +} +/* + * calculates the closest point between point-tri (2D) + * returns that tri must be right-handed + * Returns square distance + */ +static float closest_point_in_tri2D(const float point[2], /*const*/ float tri[3][2], float closest[2]) +{ + float edge_di[2]; + float v_point[2]; + float proj[2]; //point projected over edge-dir, edge-normal (witouth normalized edge) + const float *v0 = tri[2], *v1; + float edge_slen, d; //edge squared length + int i; + const float *nearest_vertex = NULL; + + + //for each edge + for(i=0, v0=tri[2], v1=tri[0]; i < 3; v0=tri[i++], v1=tri[i]) + { + VECSUB2D(edge_di, v1, v0); + VECSUB2D(v_point, point, v0); + + proj[1] = v_point[0]*edge_di[1] - v_point[1]*edge_di[0]; //dot product with edge normal + + //point inside this edge + if(proj[1] < 0) + continue; + + proj[0] = v_point[0]*edge_di[0] + v_point[1]*edge_di[1]; + + //closest to this edge is v0 + if(proj[0] < 0) + { + if(nearest_vertex == NULL || nearest_vertex == v0) + nearest_vertex = v0; + else + { + //choose nearest + return choose_nearest(nearest_vertex, v0, point, closest); + } + i++; //We can skip next edge + continue; + } + + edge_slen = edge_di[0]*edge_di[0] + edge_di[1]*edge_di[1]; //squared edge len + //closest to this edge is v1 + if(proj[0] > edge_slen) + { + if(nearest_vertex == NULL || nearest_vertex == v1) + nearest_vertex = v1; + else + { + return choose_nearest(nearest_vertex, v1, point, closest); + } + continue; + } + + //nearest is on this edge + d= proj[1] / edge_slen; + closest[0] = point[0] - edge_di[1] * d; + closest[1] = point[1] + edge_di[0] * d; + + return proj[1]*proj[1]/edge_slen; + } + + if(nearest_vertex) + { + VECSUB2D(v_point, nearest_vertex, point); + VECCOPY2D(closest, nearest_vertex); + return v_point[0]*v_point[0] + v_point[1]*v_point[1]; + } + else + { + VECCOPY(closest, point); //point is already inside + return 0.0f; + } +} + +/* + * Returns the square of the minimum distance between the point and a triangle surface + * If nearest is not NULL the nearest surface point is written on it + */ +static float nearest_point_in_tri_surface(const float *point, const float *v0, const float *v1, const float *v2, float *nearest) +{ + //Lets solve the 2D problem (closest point-tri) + float normal_dist, plane_sdist, plane_offset; + float du[3], dv[3], dw[3]; //orthogonal axis (du=(v0->v1), dw=plane normal) + + float p_2d[2], tri_2d[3][2], nearest_2d[2]; + + CalcNormFloat((float*)v0, (float*)v1, (float*)v2, dw); + + //point-plane distance and calculate axis + normal_dist = point_plane_distance(point, v0, dw); + + // OPTIMIZATION + // if we are only interested in nearest distance if its closer than some distance already found + // we can: + // if(normal_dist*normal_dist >= best_dist_so_far) return FLOAT_MAX; + // + + VECSUB(du, v1, v0); + Normalize(du); + Crossf(dv, dw, du); + plane_offset = INPR(v0, dw); + + //project stuff to 2d + tri_2d[0][0] = INPR(du, v0); + tri_2d[0][1] = INPR(dv, v0); + + tri_2d[1][0] = INPR(du, v1); + tri_2d[1][1] = INPR(dv, v1); + + tri_2d[2][0] = INPR(du, v2); + tri_2d[2][1] = INPR(dv, v2); + + p_2d[0] = INPR(du, point); + p_2d[1] = INPR(dv, point); + + //we always have a right-handed tri + //this should always happen because of the way normal is calculated + plane_sdist = closest_point_in_tri2D(p_2d, tri_2d, nearest_2d); + + //project back to 3d + if(nearest) + { + nearest[0] = du[0]*nearest_2d[0] + dv[0] * nearest_2d[1] + dw[0] * plane_offset; + nearest[1] = du[1]*nearest_2d[0] + dv[1] * nearest_2d[1] + dw[1] * plane_offset; + nearest[2] = du[2]*nearest_2d[0] + dv[2] * nearest_2d[1] + dw[2] * plane_offset; + } + + return plane_sdist + normal_dist*normal_dist; +} + + +/* + * BVH from meshs callbacks + */ + +// Callback to bvh tree nearest point. The tree must bust have been built using bvhtree_from_mesh_faces. +// userdata must be a BVHMeshCallbackUserdata built from the same mesh as the tree. +static void mesh_faces_nearest_point(void *userdata, int index, const float *co, BVHTreeNearest *nearest) +{ + const BVHTreeFromMesh *data = (BVHTreeFromMesh*) userdata; + MVert *vert = data->vert; + MFace *face = data->face + index; + + float *t0, *t1, *t2, *t3; + t0 = vert[ face->v1 ].co; + t1 = vert[ face->v2 ].co; + t2 = vert[ face->v3 ].co; + t3 = face->v4 ? vert[ face->v4].co : NULL; + + + do + { + float nearest_tmp[3], dist; + + dist = nearest_point_in_tri_surface(co,t0, t1, t2, nearest_tmp); + if(dist < nearest->dist) + { + nearest->index = index; + nearest->dist = dist; + VECCOPY(nearest->co, nearest_tmp); + CalcNormFloat((float*)t0, (float*)t1, (float*)t2, nearest->no); //TODO.. (interpolate normals from the vertexs coordinates? + } + + + t1 = t2; + t2 = t3; + t3 = NULL; + + } while(t2); +} + +// Callback to bvh tree raycast. The tree must bust have been built using bvhtree_from_mesh_faces. +// userdata must be a BVHMeshCallbackUserdata built from the same mesh as the tree. +static void mesh_faces_spherecast(void *userdata, int index, const BVHTreeRay *ray, BVHTreeRayHit *hit) +{ + const BVHTreeFromMesh *data = (BVHTreeFromMesh*) userdata; + MVert *vert = data->vert; + MFace *face = data->face + index; + + float *t0, *t1, *t2, *t3; + t0 = vert[ face->v1 ].co; + t1 = vert[ face->v2 ].co; + t2 = vert[ face->v3 ].co; + t3 = face->v4 ? vert[ face->v4].co : NULL; + + + do + { + float dist; + if(data->sphere_radius == 0.0f) + dist = ray_tri_intersection(ray, hit->dist, t0, t1, t2); + else + dist = sphereray_tri_intersection(ray, data->sphere_radius, hit->dist, t0, t1, t2); + + if(dist >= 0 && dist < hit->dist) + { + hit->index = index; + hit->dist = dist; + VECADDFAC(hit->co, ray->origin, ray->direction, dist); + + CalcNormFloat(t0, t1, t2, hit->no); + } + + t1 = t2; + t2 = t3; + t3 = NULL; + + } while(t2); +} + +/* + * BVH builders + */ +// Builds a bvh tree.. where nodes are the vertexs of the given mesh +void bvhtree_from_mesh_verts(BVHTreeFromMesh *data, DerivedMesh *mesh, float epsilon, int tree_type, int axis) +{ + int i; + int numVerts= mesh->getNumVerts(mesh); + MVert *vert = mesh->getVertDataArray(mesh, CD_MVERT); + BVHTree *tree = NULL; + + memset(data, 0, sizeof(*data)); + + if(vert == NULL) + { + printf("bvhtree cant be build: cant get a vertex array"); + return; + } + + tree = BLI_bvhtree_new(numVerts, epsilon, tree_type, axis); + if(tree != NULL) + { + for(i = 0; i < numVerts; i++) + BLI_bvhtree_insert(tree, i, vert[i].co, 1); + + BLI_bvhtree_balance(tree); + + data->tree = tree; + + //a NULL nearest callback works fine + //remeber the min distance to point is the same as the min distance to BV of point + data->nearest_callback = NULL; + data->raycast_callback = NULL; + + data->mesh = mesh; + data->vert = mesh->getVertDataArray(mesh, CD_MVERT); + data->face = mesh->getFaceDataArray(mesh, CD_MFACE); + + data->sphere_radius = epsilon; + } +} + +// Builds a bvh tree.. where nodes are the faces of the given mesh. +void bvhtree_from_mesh_faces(BVHTreeFromMesh *data, DerivedMesh *mesh, float epsilon, int tree_type, int axis) +{ + int i; + int numFaces= mesh->getNumFaces(mesh); + MVert *vert = mesh->getVertDataArray(mesh, CD_MVERT); + MFace *face = mesh->getFaceDataArray(mesh, CD_MFACE); + BVHTree *tree = NULL; + + memset(data, 0, sizeof(*data)); + + if(vert == NULL && face == NULL) + { + printf("bvhtree cant be build: cant get a vertex/face array"); + return; + } + + /* Create a bvh-tree of the given target */ + tree = BLI_bvhtree_new(numFaces, epsilon, tree_type, axis); + if(tree != NULL) + { + for(i = 0; i < numFaces; i++) + { + float co[4][3]; + VECCOPY(co[0], vert[ face[i].v1 ].co); + VECCOPY(co[1], vert[ face[i].v2 ].co); + VECCOPY(co[2], vert[ face[i].v3 ].co); + if(face[i].v4) + VECCOPY(co[3], vert[ face[i].v4 ].co); + + BLI_bvhtree_insert(tree, i, co[0], face[i].v4 ? 4 : 3); + } + BLI_bvhtree_balance(tree); + + data->tree = tree; + data->nearest_callback = mesh_faces_nearest_point; + data->raycast_callback = mesh_faces_spherecast; + + data->mesh = mesh; + data->vert = mesh->getVertDataArray(mesh, CD_MVERT); + data->face = mesh->getFaceDataArray(mesh, CD_MFACE); + + data->sphere_radius = epsilon; + } +} + +// Frees data allocated by a call to bvhtree_from_mesh_*. +void free_bvhtree_from_mesh(struct BVHTreeFromMesh *data) +{ + if(data->tree) + { + BLI_bvhtree_free(data->tree); + memset( data, 0, sizeof(data) ); + } +} + + |