a) Enable the possibility to remove the "air bubble" around submerged collision object. This feature is enabled as standard for new files. The code was found in elbeem by nudelZ, coded and provided by Nils Thürey (thanks!)
b) Old baked files gets deleted if a new bake gets started (were overwritten before and resulted in weird old bake + new bake mixture) (idea by nudelZ)
The main purpose for this is to allow rendering motion blurred blender fluids in external renderers (eg. http://vimeo.com/21870635 ).
Python code snippet for interpreting this data here: http://www.pasteall.org/21577 . Cleaned up some ugly hacks in this area too
* Also added read-only access to scene.subframe to RNA - setting current frame and subframe should still go via scene.frame_set()
This commit restores fluid sim baking functionality in 2.5, it's been on the todo for
a while, and was previously almost completely non-functional. The old
code was quite complicated and specific to the 2.4 animation system, so I've
pretty much rewritten most of it.
This includes:
* Animated variables work again - just key them in the UI. Non-animateable values
should be already set non-animateable in RNA, hopefully I got them all.
Available are: Domain Gravity / Domain Viscosity / Object loc/rot/scale /
Object initial velocity / Deforming meshes / Fluid control Attract strength /
Fluid control Attract radius / Fluid control Velocity strength /
Fluid control Velocity radius / Object Active status (checkbox next to fluid type)
The Domain time scale is still not yet implemented.
* Fluid sim now use global scene units data by default - when enabled, the
scene's global gravity value is used and when units are set (metric/imperial)
the simulation real world size is taken from the object's actual measurements.
* The baking process is now done in the background, using the nifty threaded
Jobs system. It's non-blocking and your domain object will show the simulated
fluid as it becomes available for that frame.
A nice extra thing for the future would be to improve the visualisation of the
object's state while baking, and also the jobs system/ui could do with some
touchups - currently it has to share a bit from the 'render' job, and appears as
'Render' in the header. Progress bars for jobs in the header would be great too.
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?
* DNA_object_fluidsim.h: done, patch by Nathaniel Garbutt, thanks!
Some changes to make it more complete and adding inheritance to
better hide irrelevant and reused properties.
* Also added all derived types for modifiers, but only fluid is
filled in currently.
* Some files converted from DOS to UNIX line endings.
#4742 exported normals are now correct
#4821 & 4956 for complex movements in/outflows can now also
use the animated mesh option
- new features
* isosurface subdivision: directly
creates a finer surface mesh from the simulation data.
this increases simulation time and harddisk usage, though, so
be careful - usually values of 2-4 should be enough.
* fluidsim particles: extended model for particle
simulation and generation. When isosurface subdivision is enabled,
the particles are now included in the surface generation,
giving a better impression of a single connected surface.
Note - the particles are only included in the final surface
mesh, so the preview surface shows none of the particle
effects.
* particle loading: different types of particles can now be selected for
display: drops, floats and tracers. This is a bit obsolete
due to the extensions mentioned above, but might still be useful.
Floats are just particles floating on the fluid surface, could
be used for e.g. foam.
* moving objects impact factor: this is another tweaking option,
as the handling of moving objects is still not conserving
mass. setting this to zero simply deletes the fluid, 1 is
the default, while larger values cause a stronger
impact. For tweaking the simulation: if fluid disappears, try
increasing this value, and if too much is appearing reduce it.
You can even use negative values for some strange results :)
- more code cleanup, e.g. removed config file writing in fluidsim.c,
added additional safety checks for particles & fluidsim domains (these
currently dont work together). I also removed the "build particles"
debug message in effects.c (seemed to be unnecessary?).
Some more info on the new features:
Here are two test animations showing the difference between
using the particle generation with isosurface subdivision.
This is how it would look with the old solver version:
http://www10.informatik.uni-erlangen.de/~sinithue/blender/fluid6_fl6manc4_1noparts.mpg
and this with the new one:
http://www10.informatik.uni-erlangen.de/~sinithue/blender/fluid6_fl6manc4_2wparts.mpg
Both simulations use a resolution of 64, however, the version with particles
takes significantly longer (almost twice as long).
The .blend file for a similar setup can be found here:
http://www10.informatik.uni-erlangen.de/~sinithue/blender/fluid6_testmanc4.blend
(Minor Tips for this file: dont enable subdivions of characters until rendering,
thus leave off for simulation, as it uses the rendering settings! For making
nice pictures switch on subdivion, and OSA.)
And here's a picture of old vs. new (for webpage or so):
http://www10.informatik.uni-erlangen.de/~sinithue/blender/fluid6_manc4compare.png
- Added part of Austin's msvc8 fixes (vector::erase function
was "misused"), hopefully compiles better now.
- Ctrl-b now also bakes a selected fluidsim domain
similar to the softbodies.
- Added surface smoothing option for domains: default is
1, higher values result in a smoother surface (and probably
slightly higher comupation times), while 0 means the surface
is not modified at all.
- Added BLENDER_ELBEEMBOBJABORT environment variable in readBobj,
if >0 quits blender when a not yet existing fluidsim
frame should be loaded. Useful for rendering simulations
as far as possible from the command line.
- Surface normals pointer is now set to NULL in readfile.c
- Fixed win32 error string handling, now uses a function
to return the string from the solver.
- Fixed fluidsim particle halo scaling problem.
- Solver update
issues in parallel... So this commit contains: an update of
the solver (e.g. moving objects), integration of blender IPOs,
improved rendering (motion blur, smoothed normals) and a first particle
test. In more detail:
Solver update:
- Moving objects using a relatively simple model, and not yet fully optimized - ok
for box falling into water, water in a moving glass might cause trouble. Simulation
times are influenced by overall no. of triangles of the mesh, scaling meshes up a lot
might also cause slowdowns.
- Additional obstacle settings: noslip (as before), free slip (move along wall freely)
and part slip (mix of both).
- Obstacle settings also added for domain boundaries now, the six walls of the domain are
obstacles after all as well
- Got rid of templates, should make compiling for e.g. macs more convenient,
for linux there's not much difference. Finally got rid of parser (and some other code
parts), the simulation now uses the internal API to transfer data.
- Some unnecessary file were removed, the GUI now needs 3 settings buttons...
This should still be changed (maybe by adding a new panel for domain objects).
IPOs:
- Animated params: viscosity, time and gravity for domains. In contrast
to normal time IPO for Blender objects, the fluidsim one scales the time
step size - so a constant 1 has no effect, values towards 0 slow it down,
larger ones speed the simulation up (-> longer time steps, more compuations).
The viscosity IPO is also only a factor for the selected viscosity (again, 1=no effect).
- For objects that are enabled for fluidsim, a new IPO type shows up. Inflow
objects can use the velocity channels to animate the inflow. Obstacles, in/outflow
objects can be switched on (Active IPO>0) and off (<0) during the simulation.
- Movement, rotation and scaling of those 3 types is exported from the normal
Blender channels (Loc,dLoc,etc.).
Particles:
- This is still experimental, so it might be deactivated for a
release... It should at some point be used to model smaller splashes,
depending on the the realworld size and the particle generation
settings particles are generated during simulation (stored in _particles_X.gz
files).
- These are loaded by enabling the particle field for an arbitrary object,
which should be given a halo material. For each frame, similar to the mesh
loading, the particle system them loads the simulated particle positions.
- For rendering, I "abused" the part->rt field - I couldnt find any use
for it in the code and it seems to work fine. The fluidsim particles
store their size there.
Rendering:
- The fluidims particles use scaled sizes and alpha values to give a more varied
appearance. In convertblender.c fluidsim particle systems use the p->rt field
to scale up the size and down the alpha of "smaller particles". Setting the
influence fields in the fluidims settings to 0 gives equally sized particles
with same alpha everywhere. Higher values cause larger differences.
- Smoothed normals: for unmodified fluid meshes (e.g. no subdivision) the normals
computed by the solver are used. This is basically done by switching off the
normal recalculation in convertblender.c (the function calc_fluidsimnormals
handles other mesh inits instead of calc_vertexnormals).
This could also be used to e.g. modify mesh normals in a modifier...
- Another change is that fluidsim meshes load the velocities computed
during the simulation for image based motion blur. This is inited in
load_fluidsimspeedvectors for the vector pass (they're loaded during the
normal load in DerivedMesh readBobjgz). Generation and loading can be switched
off in the settings. Vector pass currently loads the fluidism meshes 3 times,
so this should still be optimized.
Examples:
- smoothed normals versus normals from subdividing once:
http://www10.informatik.uni-erlangen.de/~sinithue/temp/v060227_1smoothnorms.pnghttp://www10.informatik.uni-erlangen.de/~sinithue/temp/v060227_2subdivnorms.png
- fluidsim particles, size/alpha influence 0:
http://www10.informatik.uni-erlangen.de/~sinithue/temp/v060227_3particlesnorm.png
size influence 1:
http://www10.informatik.uni-erlangen.de/~sinithue/temp/v060227_4particlessize.png
size & alpha influence 1:
http://www10.informatik.uni-erlangen.de/~sinithue/temp/v060227_5particlesalpha.png
- the standard drop with motion blur and particles:
http://www10.informatik.uni-erlangen.de/~sinithue/temp/elbeemupdate_t2new.mpg
(here's how it looks without
http://www10.informatik.uni-erlangen.de/~sinithue/temp/elbeemupdate_t1old.mpg)
- another inflow animation (moving, switched on/off) with a moving obstacle
(and strong mblur :)
http://www10.informatik.uni-erlangen.de/~sinithue/temp/elbeemupdate_t3ipos.mpg
Things still to fix:
- rotating & scaling domains causes wrong speed vectors
- get rid of SDL code for threading, use pthreads as well?
- update wiki documentation
- cool effects for rendering would be photon maps for caustics,
and motion blur for particles :)
replace the original one. so modifiers now work with them
(apply modifier, or edit mode still work on original mesh).
this should fix the three fluidsim bugs in the tracker.
- fixed stupid makesdna problem (writing "char string[160+80]" isnt
a good idea :)
- changed GUI a bit, now displays an estimate of the required memory,
there's still a problem with redrawing (currently relies on a call
to the derived mesh generation)
- the fluidsim struct changed to store the bounding box,
and the current loaded surface mesh
- temporary simulation files are now removed if env. var.
BLENDER_DELETEELBEEMFILES is not set or zero
- fluidsimSettingsFree now gets properly called when freeing an object
in this case only the new blenderdummy.cpp and utilities.cpp have to be compiled
- restructured gui:
* domain options split up into 2 sections
* added compressibility and refinement settings
* added inflow/outflow object types
- increased progress bar by 1
