diff options
author | Sybren A. Stüvel <sybren@stuvel.eu> | 2015-02-01 13:58:10 +0300 |
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committer | Sybren A. Stüvel <sybren@stuvel.eu> | 2015-02-01 15:06:00 +0300 |
commit | 9fa628f35be31a18edfdb1e1fca8a6bd3b6b453c (patch) | |
tree | 999052f41e41117200da4bb1d177ffc6a7ff9fab /source | |
parent | 8c7e1b648b782542c4906ccb849c39b167265558 (diff) |
mathutils: added exponential map to Quaternion
Added conversion to and from exponential map representation. This
representation is useful for interpolation of > 2 quaternions, or in
PD controllers.
Implementation in C functions quat_to_expmap,
quat_normalized_to_expmap, and expmap_to_quat with Python API, unit
tests and documentation.
Added Quaternion.to_exponential_map() and Quaternion(3-vector) to
Python API.
Reviewers: campbellbarton
Projects: #bf_blender
Differential Revision: https://developer.blender.org/D1049
Diffstat (limited to 'source')
-rw-r--r-- | source/blender/blenlib/BLI_math_rotation.h | 5 | ||||
-rw-r--r-- | source/blender/blenlib/intern/math_rotation.c | 34 | ||||
-rw-r--r-- | source/blender/python/mathutils/mathutils_Quaternion.c | 40 |
3 files changed, 78 insertions, 1 deletions
diff --git a/source/blender/blenlib/BLI_math_rotation.h b/source/blender/blenlib/BLI_math_rotation.h index 905889a33d7..fbd026f7617 100644 --- a/source/blender/blenlib/BLI_math_rotation.h +++ b/source/blender/blenlib/BLI_math_rotation.h @@ -119,6 +119,11 @@ void mat4_to_axis_angle(float axis[3], float *angle, float M[4][4]); void axis_angle_to_mat3_single(float R[3][3], const char axis, const float angle); void angle_to_mat2(float R[2][2], const float angle); +/****************************** Exponential Map ******************************/ +void quat_to_expmap(float expmap[3], const float q[4]); +void quat_normalized_to_expmap(float expmap[3], const float q[4]); +void expmap_to_quat(float r[4], const float expmap[3]); + /******************************** XYZ Eulers *********************************/ void eul_to_quat(float quat[4], const float eul[3]); diff --git a/source/blender/blenlib/intern/math_rotation.c b/source/blender/blenlib/intern/math_rotation.c index 3ac031d7b90..3d5d47bc2e0 100644 --- a/source/blender/blenlib/intern/math_rotation.c +++ b/source/blender/blenlib/intern/math_rotation.c @@ -1016,6 +1016,40 @@ void angle_to_mat2(float mat[2][2], const float angle) mat[1][1] = angle_cos; } +/****************************** Exponential Map ******************************/ + +void quat_normalized_to_expmap(float expmap[3], const float q[4]) +{ + float angle; + BLI_ASSERT_UNIT_QUAT(q); + + /* Obtain axis/angle representation. */ + quat_to_axis_angle(expmap, &angle, q); + + /* Convert to exponential map. */ + mul_v3_fl(expmap, angle); +} + +void quat_to_expmap(float expmap[3], const float q[4]) +{ + float q_no[4]; + normalize_qt_qt(q_no, q); + quat_normalized_to_expmap(expmap, q_no); +} + +void expmap_to_quat(float r[4], const float expmap[3]) +{ + float axis[3]; + float angle; + + /* Obtain axis/angle representation. */ + angle = normalize_v3_v3(axis, expmap); + angle = angle_wrap_rad(angle); + + /* Convert to quaternion. */ + axis_angle_to_quat(r, axis, angle); +} + /******************************** XYZ Eulers *********************************/ /* XYZ order */ diff --git a/source/blender/python/mathutils/mathutils_Quaternion.c b/source/blender/python/mathutils/mathutils_Quaternion.c index 98ee2fbd7cc..786a9324adf 100644 --- a/source/blender/python/mathutils/mathutils_Quaternion.c +++ b/source/blender/python/mathutils/mathutils_Quaternion.c @@ -177,6 +177,28 @@ static PyObject *Quaternion_to_axis_angle(QuaternionObject *self) return ret; } +PyDoc_STRVAR(Quaternion_to_exponential_map_doc, +".. method:: to_exponential_map()\n" +"\n" +" Return the exponential map representation of the quaternion.\n" +"\n" +" This representation consist of the rotation axis multiplied by the rotation angle." +" Such a representation is useful for interpolation between multiple orientations.\n" +"\n" +" :return: exponential map.\n" +" :rtype: :class:`Vector` of size 3\n" +); +static PyObject *Quaternion_to_exponential_map(QuaternionObject *self) +{ + float expmap[3]; + + if (BaseMath_ReadCallback(self) == -1) + return NULL; + + quat_to_expmap(expmap, self->quat); + return Vector_CreatePyObject(expmap, 3, NULL); +} + PyDoc_STRVAR(Quaternion_cross_doc, ".. method:: cross(other)\n" "\n" @@ -1077,9 +1099,24 @@ static PyObject *Quaternion_new(PyTypeObject *type, PyObject *args, PyObject *kw case 0: break; case 1: - if (mathutils_array_parse(quat, QUAT_SIZE, QUAT_SIZE, seq, "mathutils.Quaternion()") == -1) + { + int size; + + if ((size = mathutils_array_parse(quat, 3, QUAT_SIZE, seq, "mathutils.Quaternion()")) == -1) { return NULL; + } + + if (size == 4) { + /* 4d: Quaternion (common case) */ + } + else { + /* 3d: Interpret as exponential map */ + BLI_assert(size == 3); + expmap_to_quat(quat, quat); + } + break; + } case 2: { float axis[3]; @@ -1156,6 +1193,7 @@ static struct PyMethodDef Quaternion_methods[] = { {"to_euler", (PyCFunction) Quaternion_to_euler, METH_VARARGS, Quaternion_to_euler_doc}, {"to_matrix", (PyCFunction) Quaternion_to_matrix, METH_NOARGS, Quaternion_to_matrix_doc}, {"to_axis_angle", (PyCFunction) Quaternion_to_axis_angle, METH_NOARGS, Quaternion_to_axis_angle_doc}, + {"to_exponential_map", (PyCFunction) Quaternion_to_exponential_map, METH_NOARGS, Quaternion_to_exponential_map_doc}, /* operation between 2 or more types */ {"cross", (PyCFunction) Quaternion_cross, METH_O, Quaternion_cross_doc}, |