A description of the problem is found in https://developer.blender.org/T36425#19 .
The cause of the issue was identified as roudning errors in Operators::createStroke() due
to insufficient numerical precision. Precision promotion from float to double was done in
the return values of getPoint3D/2D methods in Interface0D and its subclasses in C++
(data members stored in the 0D classes have already been in double precision).
before entering the recursion check.
Now use group tags instead of object tags, which could be a little more
efficient and was used before this patch too.
It still warns the user that there may be an error, but the baking goes
on. Also using the new is_uniform_scaled_m4() instead of float comparison.
Reported and fix suggested by Campbell Barton as a concern over 2bfc3deb
The remaining functions in blender_python.cpp changed from using the
MACRO to use python_thread_state_save/python_thread_state_restore
Since this bug only happens when 'Persistent Images' is on it was
introduced in some of the early merges with master and I never caught
it.
Thanks Daniel Salazar for helping with the bug hunting.
If we are using a mix node we still need to evaluate the BSDF lighting
even if scattering is successful.
Note: this was working for branched path (probably an oversight when
branched path support was introduced for baking, a good oversight though
;)
The scene file provided by the problem report has many degenerate faces coming from
a particle system. These zero-area faces were not expected in the ray-casting line visibility
algorithms of Freestyle. Now degenerate faces are properly excluded from the imported
mesh data and not fed to the line visibility algorithms.
The new recursion check for groups duplicating themselves has to un-set the LIB_DOIT flag after each object, otherwise it will prevent duplicating a (non-recursive) group multiple times.
To get the versioning code properly work, the condition should have been:
DNA_struct_elem_find(fd->filesdna, "FreestyleLineStyle", "MTex", "*mtex[18]")
The present commit uses another new structure member instead, to avoid referring
to the magic number 18 in the last string literal.
This was because to the filtering code, those FCurves still weren't in any
groups, and so couldn't be visible (since a temporary group is created to
house them). As a result, the visible-channels list would be empty, causing
all hidden FCurves to be treated as hidden.
These were broken by 1f3655d224, since
an argument of the wrong type was getting passed to ANIM_animdata_filter(),
resulting in no channels ever being picked up for the "visible channels" list.
