diff options
Diffstat (limited to 'source/blender/blenkernel/intern/mesh_evaluate.c')
| -rw-r--r-- | source/blender/blenkernel/intern/mesh_evaluate.c | 80 |
1 files changed, 70 insertions, 10 deletions
diff --git a/source/blender/blenkernel/intern/mesh_evaluate.c b/source/blender/blenkernel/intern/mesh_evaluate.c index 433db26ded8..b298a6a2787 100644 --- a/source/blender/blenkernel/intern/mesh_evaluate.c +++ b/source/blender/blenkernel/intern/mesh_evaluate.c @@ -2112,7 +2112,7 @@ void BKE_mesh_set_custom_normals(Mesh *mesh, float (*r_custom_loopnors)[3]) * Higher level functions hiding most of the code needed around call to * #BKE_mesh_normals_loop_custom_from_vertices_set(). * - * \param r_custom_loopnors: is not const, since code will replace zero_v3 normals there + * \param r_custom_vertnors: is not const, since code will replace zero_v3 normals there * with automatically computed vectors. */ void BKE_mesh_set_custom_normals_from_vertices(Mesh *mesh, float (*r_custom_vertnors)[3]) @@ -2386,10 +2386,10 @@ float BKE_mesh_calc_poly_uv_area(const MPoly *mpoly, const MLoopUV *uv_array) * - The resulting volume will only be correct if the mesh is manifold and has consistent * face winding (non-contiguous face normals or holes in the mesh surface). */ -static float mesh_calc_poly_volume_centroid(const MPoly *mpoly, - const MLoop *loopstart, - const MVert *mvarray, - float r_cent[3]) +static float UNUSED_FUNCTION(mesh_calc_poly_volume_centroid)(const MPoly *mpoly, + const MLoop *loopstart, + const MVert *mvarray, + float r_cent[3]) { const float *v_pivot, *v_step1; float total_volume = 0.0f; @@ -2424,6 +2424,36 @@ static float mesh_calc_poly_volume_centroid(const MPoly *mpoly, } /** + * A version of mesh_calc_poly_volume_centroid that takes an initial reference center, + * use this to increase numeric stability as the quality of the result becomes + * very low quality as the value moves away from 0.0, see: T65986. + */ +static float mesh_calc_poly_volume_centroid_with_reference_center(const MPoly *mpoly, + const MLoop *loopstart, + const MVert *mvarray, + const float reference_center[3], + float r_cent[3]) +{ + /* See: mesh_calc_poly_volume_centroid for comments. */ + float v_pivot[3], v_step1[3]; + float total_volume = 0.0f; + zero_v3(r_cent); + sub_v3_v3v3(v_pivot, mvarray[loopstart[0].v].co, reference_center); + sub_v3_v3v3(v_step1, mvarray[loopstart[1].v].co, reference_center); + for (int i = 2; i < mpoly->totloop; i++) { + float v_step2[3]; + sub_v3_v3v3(v_step2, mvarray[loopstart[i].v].co, reference_center); + const float tetra_volume = volume_tri_tetrahedron_signed_v3_6x(v_pivot, v_step1, v_step2); + total_volume += tetra_volume; + for (uint j = 0; j < 3; j++) { + r_cent[j] += tetra_volume * (v_pivot[j] + v_step1[j] + v_step2[j]); + } + copy_v3_v3(v_step1, v_step2); + } + return total_volume; +} + +/** * \note * - Results won't be correct if polygon is non-planar. * - This has the advantage over #mesh_calc_poly_volume_centroid @@ -2536,10 +2566,35 @@ bool BKE_mesh_center_median(const Mesh *me, float r_cent[3]) if (me->totvert) { mul_v3_fl(r_cent, 1.0f / (float)me->totvert); } - return (me->totvert != 0); } +/** + * Calculate the center from polygons, + * use when we want to ignore vertex locations that don't have connected faces. + */ +bool BKE_mesh_center_median_from_polys(const Mesh *me, float r_cent[3]) +{ + int i = me->totpoly; + int tot = 0; + const MPoly *mpoly = me->mpoly; + const MLoop *mloop = me->mloop; + const MVert *mvert = me->mvert; + zero_v3(r_cent); + for (mpoly = me->mpoly; i--; mpoly++) { + int loopend = mpoly->loopstart + mpoly->totloop; + for (int j = mpoly->loopstart; j < loopend; j++) { + add_v3_v3(r_cent, mvert[mloop[j].v].co); + } + tot += mpoly->totloop; + } + /* otherwise we get NAN for 0 verts */ + if (me->totpoly) { + mul_v3_fl(r_cent, 1.0f / (float)tot); + } + return (me->totpoly != 0); +} + bool BKE_mesh_center_bounds(const Mesh *me, float r_cent[3]) { float min[3], max[3]; @@ -2595,12 +2650,16 @@ bool BKE_mesh_center_of_volume(const Mesh *me, float r_cent[3]) float total_volume = 0.0f; float poly_cent[3]; + /* Use an initial center to avoid numeric instability of geometry far away from the center. */ + float init_cent[3]; + const bool init_cent_result = BKE_mesh_center_median_from_polys(me, init_cent); + zero_v3(r_cent); /* calculate a weighted average of polyhedron centroids */ for (mpoly = me->mpoly; i--; mpoly++) { - poly_volume = mesh_calc_poly_volume_centroid( - mpoly, me->mloop + mpoly->loopstart, me->mvert, poly_cent); + poly_volume = mesh_calc_poly_volume_centroid_with_reference_center( + mpoly, me->mloop + mpoly->loopstart, me->mvert, init_cent, poly_cent); /* poly_cent is already volume-weighted, so no need to multiply by the volume */ add_v3_v3(r_cent, poly_cent); @@ -2616,9 +2675,10 @@ bool BKE_mesh_center_of_volume(const Mesh *me, float r_cent[3]) /* this can happen for non-manifold objects, fallback to median */ if (UNLIKELY(!is_finite_v3(r_cent))) { - return BKE_mesh_center_median(me, r_cent); + copy_v3_v3(r_cent, init_cent); + return init_cent_result; } - + add_v3_v3(r_cent, init_cent); return (me->totpoly != 0); } |