Commit: 6202bc82b858d8f6876c6c20ec62dd0a16209087 Author: Jacques Lucke Date: Wed Feb 6 11:47:46 2019 +0100 Branches: master https://developer.blender.org/rB6202bc82b858d8f6876c6c20ec62dd0a16209087
Fix T60935: More numerically stable distance to ray computation The old function was numerically very unstable for 2 reasons: computing the square and then subtracting the results. In the example in T60935 all precision was lost and it returned the distance 0 for all points. I also removed the `depth` parameter since it wasn't used and computing it would have made the code more complicated. Reviewers: brecht, campbellbarton Differential Revision: https://developer.blender.org/D4308 =================================================================== M source/blender/blenlib/BLI_math_geom.h M source/blender/blenlib/intern/math_geom.c M source/blender/editors/mesh/editmesh_select.c =================================================================== diff --git a/source/blender/blenlib/BLI_math_geom.h b/source/blender/blenlib/BLI_math_geom.h index a564e5481b9..54a4a38b15e 100644 --- a/source/blender/blenlib/BLI_math_geom.h +++ b/source/blender/blenlib/BLI_math_geom.h @@ -109,9 +109,9 @@ float dist_signed_squared_to_corner_v3v3v3( const float p[3], const float v1[3], const float v2[3], const float v3[3], const float axis_ref[3]); -float dist_squared_to_ray_v3( +float dist_squared_to_ray_v3_normalized( const float ray_origin[3], const float ray_direction[3], - const float co[3], float *r_depth); + const float co[3]); float dist_squared_ray_to_seg_v3( const float ray_origin[3], const float ray_direction[3], const float v0[3], const float v1[3], diff --git a/source/blender/blenlib/intern/math_geom.c b/source/blender/blenlib/intern/math_geom.c index 91de4005f48..aebff346432 100644 --- a/source/blender/blenlib/intern/math_geom.c +++ b/source/blender/blenlib/intern/math_geom.c @@ -553,16 +553,25 @@ float dist_signed_squared_to_corner_v3v3v3( } /** - * return the distance squared of a point to a ray. + * Compute the squared distance of a point to a line (defined as ray). + * \param ray_origin: A point on the line. + * \param ray_direction: Normalized direction of the line. + * \param co: Point to which the distance is to be calculated. */ -float dist_squared_to_ray_v3( +float dist_squared_to_ray_v3_normalized( const float ray_origin[3], const float ray_direction[3], - const float co[3], float *r_depth) + const float co[3]) { - float dvec[3]; - sub_v3_v3v3(dvec, co, ray_origin); - *r_depth = dot_v3v3(dvec, ray_direction); - return len_squared_v3(dvec) - SQUARE(*r_depth); + float origin_to_co[3]; + sub_v3_v3v3(origin_to_co, co, ray_origin); + + float origin_to_proj[3]; + project_v3_v3v3_normalized(origin_to_proj, origin_to_co, ray_direction); + + float co_projected_on_ray[3]; + add_v3_v3v3(co_projected_on_ray, ray_origin, origin_to_proj); + + return len_squared_v3v3(co, co_projected_on_ray); } diff --git a/source/blender/editors/mesh/editmesh_select.c b/source/blender/editors/mesh/editmesh_select.c index d09f3ba6f64..fd9e635f5e3 100644 --- a/source/blender/editors/mesh/editmesh_select.c +++ b/source/blender/editors/mesh/editmesh_select.c @@ -1153,16 +1153,13 @@ bool EDBM_unified_findnearest_from_raycast( if ((BM_elem_flag_test(e, BM_ELEM_HIDDEN) == false) && (BM_edge_is_boundary(e))) { - float depth; - if (use_vert) { for (uint j = 0; j < 2; j++) { BMVert *v = *((&e->v1) + j); float point[3]; mul_v3_m4v3(point, obedit->obmat, coords ? coords[BM_elem_index_get(v)] : v->co); - const float dist_sq_test = dist_squared_to_ray_v3( - ray_origin, ray_direction, - point, &depth); + const float dist_sq_test = dist_squared_to_ray_v3_normalized( + ray_origin, ray_direction, point); if (dist_sq_test < dist_sq_best) { dist_sq_best = dist_sq_test; best.base_index = base_index; @@ -1186,9 +1183,8 @@ bool EDBM_unified_findnearest_from_raycast( mid_v3_v3v3(point, e->v1->co, e->v2->co); } mul_m4_v3(obedit->obmat, point); - const float dist_sq_test = dist_squared_to_ray_v3( - ray_origin, ray_direction, - point, &depth); + const float dist_sq_test = dist_squared_to_ray_v3_normalized( + ray_origin, ray_direction, point); if (dist_sq_test < dist_sq_best) { dist_sq_best = dist_sq_test; best.base_index = base_index; @@ -1208,10 +1204,8 @@ bool EDBM_unified_findnearest_from_raycast( if (BM_elem_flag_test(v, BM_ELEM_HIDDEN) == false) { float point[3]; mul_v3_m4v3(point, obedit->obmat, v->co); - float depth; - const float dist_sq_test = dist_squared_to_ray_v3( - ray_origin, ray_direction, - v->co, &depth); + const float dist_sq_test = dist_squared_to_ray_v3_normalized( + ray_origin, ray_direction, v->co); if (dist_sq_test < dist_sq_best) { dist_sq_best = dist_sq_test; best.base_index = base_index; @@ -1233,10 +1227,8 @@ bool EDBM_unified_findnearest_from_raycast( mid_v3_v3v3(point, e->v1->co, e->v2->co); } mul_m4_v3(obedit->obmat, point); - float depth; - const float dist_sq_test = dist_squared_to_ray_v3( - ray_origin, ray_direction, - point, &depth); + const float dist_sq_test = dist_squared_to_ray_v3_normalized( + ray_origin, ray_direction, point); if (dist_sq_test < dist_sq_best) { dist_sq_best = dist_sq_test; best.base_index = base_index; @@ -1260,10 +1252,8 @@ bool EDBM_unified_findnearest_from_raycast( BM_face_calc_center_median(f, point); } mul_m4_v3(obedit->obmat, point); - float depth; - const float dist_sq_test = dist_squared_to_ray_v3( - ray_origin, ray_direction, - point, &depth); + const float dist_sq_test = dist_squared_to_ray_v3_normalized( + ray_origin, ray_direction, point); if (dist_sq_test < dist_sq_best) { dist_sq_best = dist_sq_test; best.base_index = base_index; _______________________________________________ Bf-blender-cvs mailing list [email protected] https://lists.blender.org/mailman/listinfo/bf-blender-cvs
