This helps to create some variation in a hair system, which can
otherwise become very uniform and boring. It's yet another confusing
setting in a system that should have been nodified, but only option for
now (broken windows ...)
Conflicts:
source/blender/blenkernel/intern/particle_system.c
source/blender/physics/intern/BPH_mass_spring.cpp
This allows setting a target density which the fluid simulation will
take into account as an additional term in the pressure Poisson
equation. Based on two papers
"Detail Preserving Continuum Simulation of Straight Hair" (McAdams et al. 2009)
and
"Two-way Coupled SPH and Particle Level Set Fluid Simulation" (Losasso et al. 2008)
Currently the target pressure is specified directly, but it will be
a lot more convenient to define this in terms of a geometric value such
as "number of hairs per area" (combined with hair "thickness").
Conflicts:
source/blender/physics/intern/BPH_mass_spring.cpp
This is a bit more awkward for artists to use, but necessary for
a stable solution of the hair continuum calculation. The grid size is
defined by the user, the extent of the grid is then calculated based on
the hair geometry. A hard upper limit prevents bad memory allocation
in case too small values are entered.
Conflicts:
source/blender/physics/intern/BPH_mass_spring.cpp
more intuitive.
Also removed a couple of unused or useless features from the UI:
* collider friction is unused and replaced in favor of true collision
* spring damping refers to structural springs (stretch), which is
not noticable in hair due to extreme stiffness atm.
* pressure factors are not sure since this feature is too unstable atm.
Conflicts:
release/scripts/startup/bl_ui/properties_particle.py
Without this the particle system only shows the actual non-simulated
hairs ("guide hairs") during edit mode. These hairs are used for goals
as well, so showing them in the regular viewport is pretty important.
Also the usual hair curves are interpolated along the entire length,
which makes it very difficult to see exact vertex positions, unless
using exact powers of 2 for the segment number and match the display
steps.
Conflicts:
source/blender/blenkernel/intern/particle.c
This returns a general status (success/no-convergence/other) along with
basic statistics (min/max/average) for the error value and the number
of iterations. It allows some general estimation of the simulation
quality and detection of critical settings that could become a problem.
Better visualization and extended feedback can follow later.
This is part of the original method from "Volumetric Methods for
Simulation and Rendering of Hair". The current filter is a simple box
filter. Other energy-preserving filters such as gaussian filtering
can be implemented later.
The filter size is currently given as a cell count. This is not ideal,
rather it should use a geometrical length value, but this is too
abstract for proper artistical use. Eventually defining the whole grid
in terms of spatial size might work better (possibly using an external
object).
as forces, velocities, contact points etc.
This uses a hash table to store debug elements (dots, lines, vectors at
this point). The hash table allows continuous display of elements that
are generated only in certain time steps, e.g. contact points, while
avoiding massive memory allocation. In any case, this system is really
a development feature, but very helpful in finding issues with the
internal solver data.
on itself.
This uses the same voxel structure as the hair smoothing algorithm.
A slightly different method was suggested in the original paper
(Volumetric Methods for Simulation and Rendering of Hair), but this is
based on directing hair based on a target density, which is another
way of implementing global goals. Our own approach is to define a
pressure threshold above which the hair is repelled in the density
gradient direction to simulate internal pressure from collisions.
in the particle buttons list.
This is much more convenient than having to switch back and forth
between particle and modifier buttons. The modifier box for particles
does not contain anything useful other than these two toggles anyway.
Also fix material slot index not being properly initialized to 1, this got clamped
from zero only on drawing the UI.
Reviewed By: brecht
Differential Revision: http://developer.blender.org/D55
* Make the gap for the filtering options slightly bigger, so 1 row doesn't look so cluttered.
* Default Render Layer and Particle System list in the Properties Editor to 1 row as well, to save space.
Notes:
* Made those edits by full checking of py files, so I should have spoted most needed edits, yet it remains quite probable I missed a few ones, we'll fix if/when someone notice it...
* Also made some cleanup "on the road"!
The Emission panel now has a Use Modifier Stack option to emit particles from
the mesh with modifiers applied. Previously particles would only be emitted from
faces that exist in the original mesh. There are some caveats however:
http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.68/Tools#Particles
Some RNA Properties were not updated in UI scripts after a recent refactoring
there removing "use_" prefix from some of the boolean properties (strangely
though, while every other property attached to SPHFluidSettings.flag has gone
from "use_factor_blah" to "factor_blah", use_factor_density still keeps the old
prefix).
Systematically adding some custom id to template_list using default UI_UL_list class, this one is commoly used more than once in an area, yielding collision issues if they do not have a custom id...
(Did not add those when I created that module, because I did not thought we would actually need them in usual UI code, but turned out I was wrong).
Also made some optimizations in those py gettext funcs, when i18n is disabled at build time, no need to do pyobject -> cstring -> pyobject conversions!.
It introduces a new (py-extendable and registrable) RNA type, UIList (roughly similar to Panel one), which currently contains only "standard" list's scroll pos and size (but may be expended to include e.g. some filtering data, etc.). This now makes lists completely independent from Panels!
This UIList has a draw_item callback which allows to customize items' drawing from python, that all addons can now use. Incidentally, this also greatly simplifies the C code of this widget, as we do not code any "special case" here anymore!
To make all this work, other changes were also necessary:
* Now all buttons (uiBut struct) have a 'custom_data' void pointer, used currently to store the uiList struct associated with a given uiLayoutListBox.
* DynamicPaintSurface now exposes a new bool, use_color_preview (readonly), saying whether that surface has some 3D view preview data or not.
* UILayout class has now four new (static) functions, to get the actual icon of any RNA object (important e.g. with materials or textures), and to get an enum item's UI name, description and icon.
* UILayout's label() func now takes an optional 'icon_value' integer parameter, which if not zero will override the 'icon' one (mandatory to use "custom" icons as generated for material/texture/... previews).
Note: not sure whether we should add that one to all UILayout's prop funcs?
Note: will update addons using template list asap.
http://projects.blender.org/tracker/index.php?func=detail&aid=29681&group_id=9&atid=127
The solver was mostly implemented by John Mansour at VPAC, with help from me and with funding from the AutoCRC. The SPH formulation is due to Gingold and Monaghan, and the smoothing kernel is due to Wendland.
This solver does not replace the old one; it is available as an option. Note that the new solver uses different units than the old one. The patch page has a couple of attachments that can be used to test the new solver, particularly sphclassical_dam_s0.01_grav.blend (ignore the earlier tests). The simulation in that file compares well with a physical experimental dam break; details in a paper by Changhong Hu and Makoto Sueyoshi, also referred to on that page.
- BMO_slot_copy now only copies compatible elements.
other minor changes
- don't use text.format(...), convention for UI scripts is C style string formatting.
- rename bmo_edgenet_prepare --> bmo_edgenet_prepare_exec
- float/double warning in bevel.
Documentation & Test blend files:
------------------
http://wiki.blender.org/index.php/User:MiikaH/GSoC-2012-Smoke-Simulator-Improvements
Credits:
------------------
Miika Hamalainen (MiikaH): Student / Main programmer
Daniel Genrich (Genscher): Mentor / Programmer of merged patches from Smoke2 branch
Google: For Google Summer of Code 2012
After 2.63 there was a bugfix to take object scale into account for the duplicated
objects, but this breaks compatibility on earlier files. Now there is an option to
control if the scale should be used or not.
Scale is used by default on newer files, and not used on older ones.
* Negate label in the Vertex Groups panel was misleading to the string buttons, rather then the check boxes. Fixed it by having 2 columns.
Not ideal still, but better! :)
Issue reported by Tobias Kummer. Thanks!
