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This is often invalid, outdated or misleading
especially when splitting files.
It's more useful to git-blame to find out who has developed the code.
See P901 for script to perform these edits.
This is necessary when adding a new keyframe to a fcurve
that also has a driver.
Reviewers: brecht, campbellbarton
Differential Revision: https://developer.blender.org/D4278
When enabled, inserting keyframes into F-Curves with simple cyclic
extrapolation (the same conditions as required for cycle-aware auto
handle smoothing to activate) will take the cycle into account:
- Keyframes that are being inserted outside of the cycle bounds
are remapped to be inside the cycle. Thus it is not necessary
to be within the main iteration of the cycle when tweaking.
This becomes especially useful in the final animation tweaking
phase when the channel keys may be staggered for overlap, so
the actual master period is different for different channels.
- Modifying one of the end points of a cycle also changes the
other end point when appropriate, to preserve smooth transition.
This feature applies to both manual keyframe insertion using
'I', and auto-keyframing.
Differential Revision: https://developer.blender.org/D3140
Simple isn't a good prefix for library names since
lots of unrelated modules could be called 'simple'.
Include 'py' in module name since this is a subset of Python,
one of the main motivations for this is to be Python like/compatible.
Recently @sergey found that hard-coding evaluation of certain very
common driver expressions without calling the Python interpreter
produces a 30-40% performance improvement. Since hard-coding is
obviously not suitable for production, I implemented a proper
parser and interpreter for simple arithmetic expressions in C.
The evaluator supports +, -, *, /, (), ==, !=, <, <=, >, >=,
and, or, not, ternary if; driver variables, frame, pi, True, False,
and a subset of standard math functions that seem most useful.
Booleans are represented as numbers, since within the supported
operation set it seems to be impossible to distinguish True/False
from 1.0/0.0. Boolean operations properly implement lazy evaluation
with jumps, and comparisons support chaining like 'a < b < c...'.
Expressions are parsed into a very simple stack machine program
that can then be safely evaluated in multiple threads.
Reviewers: sergey, campbellbarton
Differential Revision: https://developer.blender.org/D3698
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
