The legacy algorithm only considers two adjacent points when computing
the bezier handles, which cannot produce satisfactory results. Animators
are often forced to manually adjust all curves.
The new approach instead solves a system of equations to trace a cubic spline
with continuous second derivative through the whole segment of auto points,
delimited at ends by keyframes with handles set by other requirements.
This algorithm also adjusts Vector handles that face ordinary bezier keyframes
to achieve zero acceleration at the Vector keyframe, instead of simply pointing
it at the adjacent point.
Original idea and implementation by Benoit Bolsee <benoit.bolsee@online.be>;
code mostly rewritten to improve code clarity and extensibility.
Reviewers: aligorith
Differential Revision: https://developer.blender.org/D2884
While such drivers will generally get evaluated too late to be of much
use during animations, it can still be useful to allow using drivers to
control a whole bunch of NLA strip properties (i.e. syncing NLA strip
timings via a single property/control).
Keyframe insertion however is still not allowed on these properties
(and an error message will now be displayed when trying to do so,
instead of silently failing), as it is useless.
Cyclic extrapolation is implemented as an f-curve modifier, so this
technically violates abstraction separation and is something of a hack.
However without such behavior achieving smooth looping with cyclic
extrapolation is extremely cumbersome.
The new behavior is applied when the first modifier is Cyclic
extrapolation in Repeat or Repeat with Offset mode without
using influence, repeat count or range restrictions.
This change in behavior means that curve handles have to be updated
when the modifier is added, removed or its options change. Due to the
way code is structured, it seems it requires a helper link to the
containing curve from the modifier object.
Reviewers: aligorith
Differential Revision: https://developer.blender.org/D2783
Noisy change, but safe, and better do it sooner than later if we are to
rework copying code. Also, previous commit shows this *is* useful to
catch some mistakes.
Things like `BLI_uniquename` had nothing, but really nothing to do in
BLI_path_util files!
Also, got rid of length limitation in `BLI_uniquename_cb`, we can use
alloca here to avoid overhead of malloc while keeping free size (within
reasonable limits of course).
Drivers can use this to refer to the data which the driver is applied to,
useful for objects, bones, to avoid having to create a variable pointing to its self.
FCurve evaluation depended on FCurve.curval, which isn't threadsafe.
Now only use this value for debug display,
and pass the value instead of storing in the FCurve for all but debug-display.
This was a feature request from a few years back (IIRC from ZanQdo?) to make it
easier to reuse one set of driver variables across several different drivers.
Dev Notes:
* Finally it's done! All that trouble for two little buttons.
* Grr... cmake... grrr!
Support for driver variables that don't resolve to numbers, eg:
objects, bones, curves... etc.
Without this, Python expressions to access this data needed to use an absolute path from `bpy.data`,
however this is inconvenient, breaks easily (based on naming) and wouldn't set the dependencies correctly.
Now, when trying to insert a keyframe on a driven property (using IKEY, or with
autokeying enabled), the keyframes will get created on the Driver's F-Curve
(instead of creating a new FCurve that goes into the active action, but will never
do anything). Furthermore, the x-value of the new keyframe will be the current
result of the driver expression.
Why/Motivations:
This way, it becomes easier to create corrective drivers, as you can position all
the targets the driver depends on, then adjust the driver value until it does what
you need, and then you keyframe that value to bake it into the Driver F-Curve
(in effect, "training" the computer how to behave in that case).
Usage Notes:
* In practice, that particular workflow is still quite clunky to achieve, due to some
quirks of how the driver system and the UI widgets interact. Specifically, you'll
need to disable/mute the driver before trying to edit the setting (to prevent the
driver from immediately resetting the value - before even autokey fires!). However,
if you're using the Graph Editor to preview/monitor/manage the keying process, you'll
then want to re-enable the driver before changing the targets, so that you can see
how much of a change you'll want to be applying!
* The warning about editing driver values may need to be disabled or selectively
knocked out. I had it disabled while testing this functionality, but it's actually
harmless in its current state (if just a bit annoying).
When attempting to change a driver variable name to an "invalid" name,
an indicator will now be shown beside the offending variable name.
Clicking on this icon will show a popup which provides more information
about why the variable name cannot be used.
Reasons that it knows about are:
1) Starts with number
2) Has a dot
3) Has a space
4) Starts with or contains a special character
5) Starts with an underscore (Python does allow this, but it's bad practice,
and makes checking security of drivers harder)
6) Is a reserved Python keyword
This commit simplifies the logic for finding the control curves for NLA strips,
thus eliminating a whole bunch of weird errors that were happening here. It should
also fix a number of other related issues here.
- Add blentranslation `BLT_*` module.
- moved & split `BLF_translation.h` into (`BLT_translation.h`, `BLT_lang.h`).
- moved `BLF_*_unifont` functions from `blf_translation.c` to new source file `blf_font_i18n.c`.
There were some reported data race conditions in the python interpreter which
seems to be rather valid.
Surely this is not very pretty solution, but it might solve some annoying bugs
related on threading.
Logically, it makes sense that this parameter only gets used to describe the action
that the F-Curve actually belongs to (if it belongs to one). Otherwise, it should not
be set at all.
So far, we had an operator to 'bake' keyframe curves into samples, but no
way to make the fcurve editable again (i.e. to convert it back into a keyframes one).
Needed to fix mocap addon (see T43259).
Also, fixed a glitch in `fcurve_store_samples()`, since given end frame is included in range,
it is valid to give same start and end frame (in case you want a single point in samples,
not much practical cases, but...).
Own fault in rBb154aa8c060a60d to fix T42447... Reverted that commit, and added
kind of not-so-nice hack instead.
Note root of the issue comes from the special case we are doing here re 'Local'
space of parent-less objects. In that case, local space should be the same as
world one, but instead we apply the object rotation to it... This is inconsistent
with all other cases and could very well lead to other issues as T42447, but afraid
fixing that properly would be rather hairy - not to mention it would likely break
all existing riggings etc. :(
Should be safe for a 2.73a, shall we need it.
Small optimisation (which shouldn't have much of an effect) where we skip
complex handle calculations if all the handles/verts for a Bezier curve
segment are all flat.
Patch by Campbell (T40372 -> F91346)
When the active action is a NLA strip, the keyframe indicator colors for buttons
and the 3D view indicator (i.e. the current frame indicator changes color) didn't
work correctly. This was because they were still checking for keyframes in
"global" time space, whereas they needed to be applying NLA corrections to
"look inside" the remapped action.
This is only a (hacky) partial fix, actually, since `RNA_property_animated()` will still
not work in those cases... Better that than nothing, though.
Thanks to Campbell for review.
The "Show All" and "Show Selected" operators in the Graph Editor was taking into
account all handles on keyframes, even when some of those would be invalid and/or
set to nonsense values (e.g. for any interpolation mode other than "Bezier")
