It is now possible to create "scripted expression" drivers by simply
clicking on some property, and typing some short Python expression
prefixed with a '#'. This will result in a scripted expression driver,
with the typed-in text being created.
For example, you can click on X-Location of the default cube, and
type:
#sin(frame)
and a new driver will be created for the x-location of the cube. This
will use the current frame value, and modulate this with a sine wave.
Do note though, that the current frame is a special case here. In the
current implementation, a special "frame" driver variable, which
references the current scene frame is created automatically, so that
this simple and (assumed) common case will work straight out of the
box.
Future improvements:
- Explore possibilities of semi-automated extraction of variables from
such expressions, resulting in automated variable extraction. (Doing
away with variables completely is definitely 100% off the agenda
though)
- Look into some ways of defining some shorthands for referencing
local data (possibly related to variable extraction?)
* macro ABS has no effect with uintptr_t anyway and was throwing warning (promoted to error) -> commented out and marked with TODO
* removed two unused variables trhowing warning also promoted to error when compiling.
Objects with drivers are now treated as needing updates when the
current frame changes. This assumption has been documented in the
code, and should at least mean that users who try to use drivers for
creating simple time-based expressions that this should work.
Note:
- It is still recommended to create a "cfra" driver variable instead
of actually inlining bpy.context.scene.frame_current into the
expressions. Not only does the latter look rather nasty to type/have
in the expression, but it is also less future-proof for when I get
around to actually working on a beefed-up depsgraph (nothing official
on that front yet...)
===========================
- Removed TRACK_PROCESSED flag which is actually unneeded now.
- When libmv fails to track marker for next frame, add marker
for new frame with old position and set it up as Disabled.
- "Break" track path when markers sequence is "broken".
This means path wouldn't be drawed over frames, during which
racking object was lost.
- Update Properties Editor for SpaceClip during playback.
Track preview button should now update nicely.
===========================
- Fixed bug with swapped width/height used for per-pixel cycle
when disabling color channel to be used for tracking.
- Marker preview is now using sub-pixel precision.
- Tracking stuff uses the same imbug generation function
as preview area does. Sub-pixel precision should be ok
now here too.
===========================
- Removed unneeded checking of marker==NULL
- Tracks could be named now.
- Implemented "Follow Track" constraint to "parent"
objects to tracks from movie clip.
- Added operator to create such constraint for active object
using clip and track from current context.
* Removed frame-number display from NLA strips. Indeed doing so makes
things look cleaner/easier to identify.
* When transforming NLA strips, the "temp-metas" (purple strips) get
their frame extents drawn on either end, like in the sequencer, which
seems to be easier to read than the ones inside the strips.
---
The downside of this tweak is that there is no longer any visual
feedback for which strips run reversed instead of forwards, as that
used to be shown using the frame extents stuff.
