Re-order checks to ensure a zeroed matrix results in a quaternion
without rotation. Also avoid some redundant calculation where the
'trace' was calculated but not used, flip the scaling value early
on instead of negating the quaternion after calculating it.
Making the callers responsible for this isn't practical as matrices are
often passed indirectly to a functions such as mat3_to_axis_angle,
BKE_object_mat3_to_rot & BKE_pchan_mat3_to_rot.
Or the matrix is combined from other matrices which could be negative.
Given quaternions calculated from negative matrices are completely
invalid and checking only needs to negate matrices with a negative
determinant, move the check into mat3_to_quat and related functions.
Add mat3_normalized_to_quat_fast for cases no error checking on the
input matrix is needed such as blending rotations.
When plotting equally distant points around a circle support an extra
axis of symmetry so twice as many exact values are repeated than
originally added in [0], see code-comments for a detailed explanation.
Tests to ensure accuracy and exact symmetry have been added too.
Follow up on fix for T87779.
[0]: 087f27a52f
Use a shorter/simpler license convention, stops the header taking so
much space.
Follow the SPDX license specification: https://spdx.org/licenses
- C/C++/objc/objc++
- Python
- Shell Scripts
- CMake, GNUmakefile
While most of the source tree has been included
- `./extern/` was left out.
- `./intern/cycles` & `./intern/atomic` are also excluded because they
use different header conventions.
doc/license/SPDX-license-identifiers.txt has been added to list SPDX all
used identifiers.
See P2788 for the script that automated these edits.
Reviewed By: brecht, mont29, sergey
Ref D14069
This is almost always meaningless as most code has changed
since the comment was added. Besides this, version control can be used
to check if/when a file was modified.
Some cases of this were kept when they contain details
about the original copyright holder.
- Added space below non doc-string comments to make it clear
these aren't comments for the symbols directly below them.
- Use doxy sections for some headers.
- Minor improvements to doc-strings.
Ref T92709
It turns out that after the fix to T83196 (rB814b2787cadd) the matrix
to quaternion conversion can produce noncanonical results in large
areas of the rotation space, when previously this was limited to
way smaller areas. This in turn causes Swing+Twist math to produce
angles beyond 180 degrees, e.g. outputting a -120..240 range.
This fixes both issues, ensuring that conversion outputs a canonical
result, and decomposition canonifies its input.
This was reported in chat by @jpbouza.
Adjust the threshold for switching from the base case to trace > 0,
based on very similar example code from www.euclideanspace.com to
avoid float precision issues when trace is close to -1.
Also, remove conversions to and from double, because using double
here doesn't really have benefit, especially with the new threshold.
Finally, add quaternion-matrix-quaternion round trip tests with
full coverage for all 4 branches.
Differential Revision: https://developer.blender.org/D9675
We have our own assert implementation, `BLI_assert()` that is prefered over the
C standard library one. Its output is more consistent across compilers and
makes termination on assert failure optional (through `WITH_ASSERT_ABORT`).
In many places we'd include the C library header without ever accessing it.
This addresses warnings from Clang-Tidy's `readability-else-after-return`
rule in the `source/blender/blenlib` module. Not all warnings are
addressed in this commit.
No functional changes.
While it might be handy to have type-less functionality which is
similar to how C++ math is implemented it can not be easily achieved
with just preprocessor in a way which does not have side-effects on
wrong usage.
There macros where often used on a non-trivial expression, and there
was at least one usage where it was causing an actual side effect/bug
on Windows (see change around square_f(sh[index++]) in studiolight.c).
For such cases it is handy to have a function which is guaranteed to
have zero side-effects. The motivation behind actually removing the
macros is that there is already a way to do similar calculation. Also,
not having such macros is a way to guarantee that its usage is not
changed in a way which have side-effects and that it's not used as an
inspiration for cases where it should not be used.
Differential Revision: https://developer.blender.org/D7051
In order to correctly drive corrective shape keys from a freely
rotating organic joint it is very often found necessary to
decompose the rotation into separate bending and twisting
motions. This type of decomposition cannot be reproduced by
any Euler order or a single quaternion.
Instead this is done by using a helper bone with a Damped Track
constraint aimed at the tail of the control to pick up the bending,
and its helper child with Copy Transforms to separate the twist.
Requiring two additional bones to drive a shape key or a correction
bone seems inconvenient, so this implements the necessary math as new
options in the recently introduced Rotation Mode dropdown of the
Transform Channel driver variable type. The data is also accessible
as a Transformation constraint input.
The output is in the form of Quaternion-derived 'pseudo-angles',
which for `Swing and Y Twist` would represent the following:
* W: true bend angle, independent of bend direction.
* Y: true twist angle.
* X, Z: pseudo-angles representing the proportion of bending around X/Z.
Reviewers: brecht
Differential Revision: https://developer.blender.org/D5651
When there was no rotation the axis was zerod,
while not exactly a bug, it means changing the angle does nothing
and all axis-angle values are initialized with Y=1,
use this convention when resetting the axis too.
