diff options
Diffstat (limited to 'source/blender/blenkernel/intern/constraint.c')
| -rw-r--r-- | source/blender/blenkernel/intern/constraint.c | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/source/blender/blenkernel/intern/constraint.c b/source/blender/blenkernel/intern/constraint.c index 2a5a0cf9ae7..7d861658993 100644 --- a/source/blender/blenkernel/intern/constraint.c +++ b/source/blender/blenkernel/intern/constraint.c @@ -3709,7 +3709,7 @@ static void damptrack_evaluate(bConstraint *con, bConstraintOb *cob, ListBase *t * - the min/max wrappers around (obvec . tarvec) result (stored temporarily in rangle) * are used to ensure that the smallest angle is chosen */ - cross_v3_v3v3(raxis, obvec, tarvec); + cross_v3_v3v3_hi_prec(raxis, obvec, tarvec); rangle = dot_v3v3(obvec, tarvec); rangle = acosf(max_ff(-1.0f, min_ff(1.0f, rangle))); @@ -3717,7 +3717,35 @@ static void damptrack_evaluate(bConstraint *con, bConstraintOb *cob, ListBase *t /* construct rotation matrix from the axis-angle rotation found above * - this call takes care to make sure that the axis provided is a unit vector first */ - axis_angle_to_mat3(rmat, raxis, rangle); + float norm = normalize_v3(raxis); + + if (norm < FLT_EPSILON) { + /* if dot product is nonzero, while cross is zero, we have two opposite vectors! + * - this is an ambiguity in the math that needs to be resolved arbitrarily, + * or there will be a case where damped track strangely does nothing + * - to do that, rotate around a different local axis + */ + float tmpvec[3]; + + if (fabsf(rangle) < M_PI - 0.01f) { + return; + } + + rangle = M_PI; + copy_v3_v3(tmpvec, track_dir_vecs[(data->trackflag + 1) % 6]); + mul_mat3_m4_v3(cob->matrix, tmpvec); + cross_v3_v3v3(raxis, obvec, tmpvec); + + if (normalize_v3(raxis) == 0.0f) { + return; + } + } + else if (norm < 0.1f) { + /* near 0 and Pi arcsin has way better precision than arccos */ + rangle = (rangle > M_PI_2) ? M_PI - asinf(norm) : asinf(norm); + } + + axis_angle_normalized_to_mat3(rmat, raxis, rangle); /* rotate the owner in the way defined by this rotation matrix, then reapply the location since * we may have destroyed that in the process of multiplying the matrix |