Now it is possible to write a Python Expression using the variable names for driver targets (see mockup from initial commit) to substitute the appropriate values into the expression.
In the __global__ namespace for PyDriver evaluation, the following modules are available:
* __builtins__ - i.e. the builtin Python functions
* bpy - new Python API
* math or m - math module
For example:
Consider a driver with three targets, named: A, B, C
Now, you could write an expression like:
C if A < 5 else B
or even:
2*C if A < 5 or A > 20 else m.PI*B
Of course, you don't have to have three targets, the above was just an example.
TODO:
* Bring back way to load pydrivers.py
* Blender.Noise equivalent would be nice to have
P.S. I hope I haven't made any terrible Python API coding errors here (i.e. mem leaks, etc.)
Drivers now support multiple targets which act as 'variables'. The targets have a short 'name' (see later), and reference some property (in much the same way as F-Curves do, using RNA-Paths) which acts as the 'value'.
These named variables can then be used in a Python Expression which relates them to each other for more fine-grained control over the result of the driver. By using only the names of these variables in the expressions, we are able to define expressions/relationships in a much more readable way, as data access is separated from data use. This makes the underlying relationships easier to understand.
By default, if no Python Expression is given, the variables are simply averaged together, so old files won't break. :)
For example, check the following diagram (thanks Cessen/Nathan V from Peach team):
http://download.blender.org/ftp/incoming/250_drivers_mockup_cessen.png
TODO List:
* Depsgraph building for new driver relationships doesn't work yet. This needs to be recoded again, but this new system makes this much easier, since the targets are clearly defined (i.e. no need to parse py expressions to get list of objects)
* Graph Editor interface for editing these needs to be rewritten
* Python function for evaluating these expressions is needed (Campbell?)
- I key over a button inserts a keyframe.
- Alt+I removes a keyframe.
- With right mouse button a menu with these options pops up.
- Buttons are colored green if the property is animated, yellow
if it is on a keyframe. I followed the colors from the UI
mockups, but the flicker on keyframes seems too distracting in
practice?
- This only works for properties on the ID itself at the moment,
path callbacks need to be filled in for all structs but mesh
still.
- It doesn't work when you're over a related label, that needs to
be made to work.
- I made it insert keyframes outside of any keyingset. Not sure
how this is supposed to integrate?
* Currently, this only works for the 'Expanded polynomial' mode, but this will be expanded to include the other modes too. Now you can modify the values and interactively see the graph in the view change.
* Disabled the backdrops (modifier 'panels') temporarily, as ROUNDBOX UI elements currently swallow all events, which is not good.
Note: the code here still uses the old-style UI definition code since the new stuff is still under heavy construction.
- Completed cleaning up the drawing code so that F-Curves with modifiers now get drawn to reflect this.
- Added a temporary operator to add modifiers (hotkey Ctrl-Shift-M)
This operator can be activated using the 'Alt-C' hotkey for now, and operates on selected + editable F-Curves. This is currently still highly experimental, and does crash
I've implemented this as a way to test out the FPoints/samples code, which will be used to provide better support of the dense F-Curves which result from importing Mocap/BVH data. These should use considerably less memory + have a few additional benefits over keyframes when they're working in a stable fashion.
Only object layers have been done for now. The implementation of this should provide a good indicator for how this should be done. Unforunately, the code for animating layer visibility is not that straightforward, since scene->base->layer (not set) settings need to be synchronised with the object->layer (set by Animato) settings.
This commit brings back the drawing code for the 'Graph Editor'. I've decided to call it this, as currently it can show either F-Curves for Animation stored in Actions, or F-Curves for Drivers.
Currently, it shows all curves, since some of the necessary filtering code (i.e. for limiting curve visibility) hasn't been put in place yet. At least this serves as good proof that we can have F-Curves from multiple sources at least.
It should be noted that the code still has to be modified to work with some of the new Animato features, such as F-Curve Modifiers (cycles are an example of one of the features that use this). Also, a nicer way to set the colours of the curves needs to be investigated.
Notes:
* Fixed a few bugs in RNA User-Preferences wrapping
* The keyframe drawing uses the new-style drawing for handles from AnimSys2. There's a minor bug that sometimes occurs, where a distorted handle gets drawn at the origin of the grid on the first run. Hints anyone?
* Removed most of the old data from SpaceIpo struct, as the new code uses that. Maybe later, the directories/files at least should get renamed.
* Removed ancient hack for NVidia/TNT drivers. It is probably no longer needed, but could be restored if someone needs it.
* Added back Auto Preview-Range tool (i.e. set preview-range from keyframe extents)
* Restored delete keyframe tool. For now, this doesn't delete empty F-Curves, even though its keyframe-api counterpart still does. I still need to figure out how to do this in the best way.
* Fixed crashes when selecting keyframes in 'object' summary channels
* Removed prototypes for a few unused/depreceated functions...
* Removed nAction struct. We'll be using good ol' bAction structs again, but putting new data in a different list. Apart from that, the data is similar enough to do so.
* Rearranged code in DNA_action_types.h while renaming the structs to avoid confusion over what is currently in use...
* Added freeing and AnimData execution loops for many other ID-types too. (NOTE: I've added AnimData in NodeTree struct too, but it's not clear to me where the relevant data-management calls should go in Nodes code).
* File writing code should now only write the new data to files
Finally, here is the basic (functional) prototype of the new animation system which will allow for the infamous "everything is animatable", and which also addresses several of the more serious shortcomings of the old system. Unfortunately, this will break old animation files (especially right now, as I haven't written the version patching code yet), however, this is for the future.
Highlights of the new system:
* Scrapped IPO-Curves/IPO/(Action+Constraint-Channels)/Action system, and replaced it with F-Curve/Action.
- F-Curves (animators from other packages will feel at home with this name) replace IPO-Curves.
- The 'new' Actions, act as the containers for F-Curves, so that they can be reused. They are therefore more akin to the old 'IPO' blocks, except they do not have the blocktype restriction, so you can store materials/texture/geometry F-Curves in the same Action as Object transforms, etc.
* F-Curves use RNA-paths for Data Access, hence allowing "every" (where sensible/editable that is) user-accessible setting from RNA to be animated.
* Drivers are no longer mixed with Animation Data, so rigs will not be that easily broken and several dependency problems can be eliminated. (NOTE: drivers haven't been hooked up yet, but the code is in place)
* F-Curve modifier system allows useful 'large-scale' manipulation of F-Curve values, including (I've only included implemented ones here): envelope deform (similar to lattices to allow broad-scale reshaping of curves), curve generator (polynomial or py-expression), cycles (replacing the old cyclic extrapolation modes, giving more control over this). (NOTE: currently this cannot be tested, as there's not access to them, but the code is all in place)
* NLA system with 'tracks' (i.e. layers), and multiple strips per track. (NOTE: NLA system is not yet functional, as it's only partially coded still)
There are more nice things that I will be preparing some nice docs for soon, but for now, check for more details:
http://lists.blender.org/pipermail/bf-taskforce25/2009-January/000260.html
So, what currently works:
* I've implemented two basic operators for the 3D-view only to Insert and Delete Keyframes. These are tempolary ones only that will be replaced in due course with 'proper' code.
* Object Loc/Rot/Scale can be keyframed. Also, the colour of the 'active' material (Note: this should really be for nth material instead, but that doesn't work yet in RNA) can also be keyframed into the same datablock.
* Standard animation refresh (i.e. animation resulting from NLA and Action evaluation) is now done completely separate from drivers before anything else is done after a frame change. Drivers are handled after this in a separate pass, as dictated by depsgraph flags, etc.
Notes:
* Drivers haven't been hooked up yet
* Only objects and data directly linked to objects can be animated.
* Depsgraph will need further tweaks. Currently, I've only made sure that it will update some things in the most basic cases (i.e. frame change).
* Animation Editors are currently broken (in terms of editing stuff). This will be my next target (priority to get Dopesheet working first, then F-Curve editor - i.e. old IPO Editor)
* I've had to put in large chunks of XXX sandboxing for old animation system code all around the place. This will be cleaned up in due course, as some places need special review.
In particular, the particles and sequencer code have far too many manual calls to calculate + flush animation info, which is really bad (this is a 'please explain yourselves' call to Physics coders!).
Joshua Leung
Brecht Van Lommel
