- HEADER (beginning of each file)
* general header:
+ 8 char: "BPHYSICS"
+ 1 int: simulation type (same as PTCacheID->type)
* custom header (same for sb, particles and cloth, but can be different for new dynamics)
+ 1 int: totpoint (number of points)
+ 1 int: data_types (bit flags for what the stored data is)
- DATA (directly after header)
*totpoint times the data as specified in data_types flags
- simulation type
soft body = 0, particles = 1, cloth = 2
- data types (more can be added easily when needed)
data flag contains
----------------------------------------
index (1<<0) 1 int (index of current point)
location (1<<1) 3 float
velocity (1<<2) 3 float
rotation (1<<3) 4 float (quaternion)
avelocity (1<<4) 3 float (used for particles)
xconst (1<<4) 3 float (used for cloth)
size (1<<5) 1 float
times (1<<6) 3 float (birth, die & lifetime of particle)
boids (1<<7) 1 BoidData
Notes:
- Every frame is not nescessary since data is interpolated for the inbetween frames.
- For now every point is needed for every cached frame, the "index" data type is reserved for future usage.
- For loading external particle caches only "location" data is necessary, other needed values are determined from the given data.
- Non-dynamic data should be written into an info file if external usage is desired.
* Info file is named as normal cache files, but with frame number 0;
* "Non-dynamic" means data such as particle times.
* Written automatically when baking to disk so basically a library of particle simulations should be possible.
- Old disk cache format is supported for reading, so pre 2.5 files shouldn't break. However old style memory cache (added during 2.5 development) is not supported. To keep memory cached simulations convert the cache to disk cache before svn update and save the blend.
- External sb and cloth caches should be perfectly possible, but due to lack of testing these are not yet enabled in ui.
Other changes:
- Multiple point caches per dynamics system.
* In the future these will hopefully be nla editable etc, but for now things are simple and the current (selected) point cache is used.
* Changing the amount of cached points (for example particle count) is allowed, but might not give correct results if multiple caches are present.
- Generalization of point cache baking etc operator & rna code.
- Comb brushing particle hair didn't work smoothly.
* Reviewed subtypes, making them more specific and adding new ones.
* Subtypes now have an associated type of units (length, area, volume,
mass, rotation, time, velocity, acceleration). These are not used
yet anywhere.
* Centralized code that decides the name of array items based on
subtype (XYZ, RGB), was copied in 3 places.
* RNA_def_float etc functions still need to be update, will do this
later together with another change.
Note: Rna access to softbody point cache is through softbody modifier although the point cache is in softbody settings. This is to make it similar to cloth.
Bugfix: Softbody rna was trying to get "ob->soft->softflag" instead of the correct "ob->softflag".
Particle point cache can now be loaded from external files.
- Activated by "external" checkbox in cache panel and giving proper folder path and file name identifier.
- External cache panel has controls for particle emission start, end, lifetime and random lifetime. These should be set according to the external data for correct playback.
- External files should be named "identifier_frame_index.bphys" or "identifier_frame.bphys" where:
* "identifier" is a freely choseable name.
* "frame" is the cached frame number.
** Six digits padded with zeros!, for example "000024".
* "index" can be used to tell caches with the same identifier apart.
** Two digits starting from zero.
** The index and the underscore before are optional. If no index is present the index number in ui should be set to -1.
- Cache file format is pure floating point numbers (in binary, not text!) with each particle's data one after the other with the following data members:
* 3 floats: particle's location vector
* 3 floats: particle's velocity vector (per second)
* 4 floats: particle's rotation quaternion
* 3 floats: particle's angular velocity vector (per second)
* 1 float: frame of the actual data (this can be non-integer for particles that are born or die between two integer frames, but otherwise should be the same as the "frame" in the file name)
- Cache files don't have to exist for each frame.
* Frames without actual data are interpolated from surrounding frames that have data (extrapolation is not supported).
- Cache file formats with extended (or reduced even) data members are in future plans for easier usage.
- Current code only does particles, don't yet know if it's applicable to cloth or sb.
- Known issue: endianness can't yet be handled in any way.
Other changes:
New hard limits for many particle parameters. Some examples:
- Maximum amount of particles: 10M particles :) And before you all go and crash your Blender trying this out remember that this limit is only for those freaks who really have the machine power to handle it. 10M particles alone take around 2.2 Gb of memory / disk space in saved file and each cached frame takes around 0.5 Gb of memory / disk space depending on cache mode.
* Known issue: To actually use this many particles they most likely need to be allocated in parts as taking hold of a 2.2Gb chunk of memory at once is probably not ok with any operating system.
- Maximum amount of children: 100k children/particle (1T childparticles here we come :D)
- Kink frequency: -100k to 100k half-rotations (really strange the previous limit was only from zero upwards)
- Path draw steps: 10 (power of 2 remember)
- Path render steps: 20 (power of 2 also!! If over 1M segments doesn't get you smooth paths then I think nothing will!)
Too many new features to list! But here are the biggies:
- Boids can move on air and/or land, or climb a goal object.
- Proper interaction with collision objects.
* Closest collision object in negative z direction is considered as ground.
* Other collision objects are obstacles and boids collide with them.
- Boid behavior rules are now added to a dynamic list.
* Many new rules and many still not implemented.
* Different rule evaluation modes (fuzzy, random, average).
- Only particle systems defined by per system "boid relations" are considered for simulation of that system.
* This is in addition to the boids own system of course.
* Relations define other systems as "neutral", "friend" or "enemy".
- All effectors now effect boid physics, not boid brains.
* This allows forcing boids somewhere.
* Exception to this is new "boid" effector, which defines boid predators (positive strength) and goals (negative strength).
Known issue:
- Boid health isn't yet stored in pointcache so simulations with "fight" rule are not be read from cache properly.
- Object/Group visualization object's animation is not played in "particle time". This is definately the wanted behavior, but isn't possible with the current state of dupliobject code.
Other new features:
- Particle systems can now be named separately from particle settings.
* Default name for particle settings is now "ParticleSettings" instead of "PSys"
- Per particle system list of particle effector weights.
* Enables different effection strengths for particles from different particle systems with without messing around with effector group setting.
Other code changes:
- KDTree now supports range search as it's needed for new boids.
- "Keyed particle targets" renamed as general "particle targets", as they're needed for boids too. (this might break some files saved with new keyed particles)
Bug fixes:
- Object & group visualizations didn't work.
- Interpolating pointcache didn't do rotation.
* Weight paint: brush strength was changed to both define weight
and strength, this can't work, made them separate buttons.
* Allow adding particle system as modifier (fix crash).
* 3D view modal ops (zoom ..) could not be ended when invoked
from a button.
* Fix some warnings.
* Fix spelling in particle RNA property.
All kinds of changes to get it ready for UI layouts. This means RNA
and operators should be working correct, but most buttons are still
not actually there yet.
* Added near empty soft body, fluid, field and collision panels,
tweaks to cloth panels.
* Fluid bake works, but without escape or showing any progress.
* Fluid/Softbody/Cloth/Collision can now be both added as modifiers
or in the physics panels.
* Missing: fields & soft body for particles.
* Missing: proper updating softbodies, guess this code still needs
updates after pointcache refactor?
* Based on what happens during simulation the cache is marked (also in cache panel, this could possibly be extended to 3d view as well) as:
- exact (not marked)
- outdated (simulation is not done completely with current settings)
- non-exact (frames were skipped during simulation)
* The parameter "cache step" effects the number of frames between saved cache frames.
- This can save a lot of memory (or disk space) if absolutely frame accurate simulation is not required.
- Speeds up the "quick caching" very much.
- Frames between cached frames are interpolated from the cached frames.
- Current default value of 10 frames works nicely with up/down-arrows (skip 10 frames forwards/backwards on timeline), but can be changed if wanted.
* The caching can work in normal or "quick" mode:
[Normal cache]
- Basic: Calculate what even happens (settings change, big frame steps etc.) and cache results, if possible try to use "cache step" when saving cache frames.
- Becomes non-exact: After larger than 1 frame steps.
- Becomes outdated: After any change effecting the simulation other than frame steps.
- Pros/cons: Freedom of doing anything and playing with particles, but exact results have to calculated from the beginning.
[Quick cache]
- Basic: Calculate simulation up to current frame automatically on changes with cache step sized jumps in simulation. With multiple "quick cached" simulations the smallest cache step is used.
- Becomes non-exact: Always from frame 1 (unless cache step = 1).
- Becomes outdated: Never.
- Pros/cons: Not very accurate, but super fast!
- Todo: Transform of any animated (non-autokeyed) object is locked! Probably needs some tinkering with anim sys overrides.
* The simulation can be run forwards or backwards even if it's cache is outdated or non-exact, the following rules apply in these situations:
- step forwards (to unknown) -> simulate from last exact frame, store result
- step backwards (to known) -> result is interpolated from existing frames, store result, clear cache forwards if current frame is after last exact frame
* "Calculate to current frame" runs the simulation from start to current frame with a frame steps of 1.
- Baking does the same, but runs the simulation all the way to the end of simulation.
- Rendering does this automatically if the simulation is outdated of non-exact, so all rendered simulations will always be updated and exact.
* Every cache panel also holds buttons to "Bake all dynamics", "Free all dynamics" and "Update all dynamics to current frame".
* Cloth simulation supports the new cache too.
* Particles support larger than 1 frame changes, bigger frame changes can result in inaccurate results, but it's super fast and you get a nice feeling of how the particles behave!
* "Cache to current frame" button calculates the exact result of particles at current frame.
* Current state of cache can be protected by making it a bake.
* Cache is now in memory by default, disk cache is an option.
* Only "viewport %" number of particles are calculated and cached in viewport, baking and rendering calculate all particles.
* Info on cached frames and memory usage given in ui.
* Support for exact "autocaching" of changes and large frame changes(disabled for now until exact place in event system is decided)
* "Continue physics" is probably deprecated after this and should be removed once sb & cloth use the new cache code.
Todo:
* Make softbody & cloth use the new cache things.
Other changes:
* Some cleanup of particle buttons.
* Added icon to property and enum property items. The latter is
responsible for the large number of files changed.
* For RNA functions, added PROP_RNAPTR flag to ask for a PointerRNA
as argument instead of a C pointer, instead of doing it implicitly
with the AnyType type.
* Material: properly wrap diffuse/specular param variables, and
rename some things for consistency.
* MaterialTextureSlot: added "enabled" property (ma->septex).
* Image: make animated property editable.
* Image Editor: make some things editable, notifiers, respect state.
* Context: fix issue with screen not being set as ID.
svn merge https://svn.blender.org/svnroot/bf-blender/trunk/blender -r19820:HEAD
Notes:
* Game and sequencer RNA, and sequencer header are now out of date
a bit after changes in trunk.
* I didn't know how to port these bugfixes, most likely they are
not needed anymore.
* Fix "duplicate strip" always increase the user count for ipo.
* IPO pinning on sequencer strips was lost during Undo.
* Added a constraint tab in the buttons window.
* Added more sequencer buttons (effect strips).
Note: Sequencer buttons will go into the sequencer itself (n-key Panel) later.
* Particle button tweaks by William Reynish. Thanks!
* Some RNA fixes and new properties.
-Many things not yet working properly :)
-Experimental new (hopefully more logical) categorization of buttons, feedback on this is very welcome.
-Separate render & draw types, for example now there is actually a render option "halo" instead of all the different point draw types.
-Particles get recalculated only from buttons that actually change something that has to be recalculated, for example changing visualization doesn't reset particles any more.
-Boid physics buttons are still missing as I'm currently redoing the whole boids code.
-Point caching is still very wip, so baking is not possible for example, but I added a few cache baking flags for rna that were/will be needed for particle buttons logic.
* Finished DNA_lamp_types.h, DNA_world_types.h and DNA_sound_types.h.
* Renamed "parent" struct property to "nested", and also remaining "from"
usage to "base".
* Added a NEVER_NULL subtype for pointers and use it for all properties
that apply.
* Make sure all structs have a description, and fix any other DOC_BROKEN
descriptions, also many other naming consistency improvements.
