The paths for parents and children are generated using the same function
with a rather obscure test to distinguish them. Modifiers (clump, kink,
roughness) should not be applied to parents though.
Different interpolation methods in compositor could lead to 0.5 pixel offset in
final renders. This is because of some inconsistency in integer coordinates
which might mean pixel corner or pixel center.
Should be all fine now.
mode.
This was caused by variation of the number of keys on child hairs due
to shortening of hair curves based on euclidian distances. The other
kink modes also shorten hairs, but use the parametric distance instead,
which does not vary with deformation of hairs.
By default this now copies from one object's local space to another
object's local space (instead of the previous world space). This is
more useful when transferring particles between objects, because it
doesn't require moving objects on top of each other, as long as they
have similar shapes.
another, including edit data (grooming).
This uses basically the same method as the existing connect/disconnect
feature. The main difference is that it allows working with multiple
objects and transferring the //particle/hair data// instead of the
//mesh// data (which is what connect/disconnect expects). This is a much
more realistic workflow when rigging, topology etc. changes and
groomed hair has to be transferred to the changed model.
This is BAD code, but the particle kinking does not make it easy to
write a non-local modifier that requires neighboring positions,
curvature, etc. The feature is needed for Gooseberry.
This adds another level of clumping on child hairs. When enabled, child
hairs chose a secondary clumping target using a Voronoi pattern. This
adds visual detail on a smaller scale, which is useful particularly when
the number of parents is relatively small.
Natural fibres behave in a similar way when they become sticky and
intertwined. Hairs close to each other form a first twisted strand, then
combine into larger strands. Similar features can be found in ropes:
http://en.wikipedia.org/wiki/Hair_twistshttp://en.wikipedia.org/wiki/Rope
Conflicts:
source/blender/blenloader/intern/versioning_270.c
Scope update is very slow for high resolutions, and currently blocks
the UI thread(!). This is especially terrible in paint modes, where
each stroke causes a scope update and unacceptable freezing.
The scopes update method tries to avoid this somewhat by skipping if the
toolbar is disabled, but this doesn't help when painting where brush
tools etc. are frequently needed. It's also a bad-level poll, with the
core system accessing a UI element.
Eventually scope updates should become a low-priority background job,
as well as becoming threaded. Until then this polling provides a usable
workaround to the most outrageous cases.
This is an alternative method to the current fixed function with a
clump factor and "shape" parameter. This function is quite limited and
does not give the desired result in many cases (e.g. long, parallel
rasta strands are problematic). So rather than trying to add more
parameters there is now a fully user-defined optional curve for setting
the tapering shape.
This contains a few pieces of code for a future "modifier" system that
would allow more flexible combination of effects. Eventually a node
system is the way to go, but the current code makes that impossible.
to prevent double-freeing/invalid mem access.
This can happen with the "virtual parents" feature, which generates both
parent and child paths. Each task free function also freed the shared
context, leading to double freeing.
Cloth data is used both for hair and actual cloth, which makes things
really difficult. The face number was used for distinguishing the two
types (no faces == hair mesh), but the extra hair data necessary for
hair sim is generated by particles and not available for edge-only cloth
meshes. This really needs to be sanitized ...
Conflicts:
source/blender/physics/intern/BPH_mass_spring.cpp
This is necessary because the hair dynamics settings are not part of the
ParticleSettings datablock, but part of the convoluted cloth modifier
inside the particle system struct. In the future this will be recoded
properly, but in the meantime presets provide a simple an unobtrusive
way to have reusable dynamics settings for hair.
Conflicts:
release/scripts/startup/bl_ui/properties_particle.py
approach does not work very well.
Using a cross section estimate still causes large oscillations due to
varying hair force based on angles. It also requires a sensible hair
thickness value (particle radius) which is difficult to control and
visualize at this point.
The new model is based purely on per-vertex forces, which seems to be
much more stable. It's also somewhat justified by the fact that each
hair vertex represents a certain mass.
Conflicts:
source/blender/physics/intern/BPH_mass_spring.cpp
The previous calculation was modulated with the angle between the wind
direction and the segments, which leads to very oscillating behavior.
Now the formula includes an estimate for the geometric cross section
of a hair segment based on the incident angle and the hair thickness
(currently just the particle size). This gives a more stable behavior
and more realistic response to wind.
Conflicts:
source/blender/blenkernel/intern/particle_system.c
source/blender/physics/intern/BPH_mass_spring.cpp
This module will contain mirrored functions for calculating and applying
weights for points on a mesh. This includes barycentric and UV weighting
and possibly more advanced global weighting such as harmonic weights.
The naming should follow this scheme:
<type>_{2d,3d}_{calc,apply}
e.g.
poly_2d_calc
poly_2d_apply
uv_3d_calc
...
Reviewers: campbellbarton
Differential Revision: https://developer.blender.org/D939
