The problem happens because smoke collides only with the surface of the
collider and uses incompressible fluid solver. This means that scaling
the collider tries to compress or decompress fluid within the volume of
the collider, which can't be handled by the simulation. Fast rotation
likely also causes transient scaling due to emulation of arcs by chords.
This can be fixed by finding compartments completely isolated by obstacles
from the rest of the domain, and forcing total divergence within each one
to be zero so that equations are solvable. Physical validity is somewhat
dubious, but without this the solver simply breaks down.
From the physics point of view, the effect of the correction should be
similar to opening a hole from every cell to another dimension that lets
an equal amount of air to pass through to balance the change in volume.
Reviewers: miikah, lukastoenne
Reviewed By: lukastoenne
Subscribers: dafassi, scorpion81, #physics
Maniphest Tasks: T43220, T47551
Differential Revision: https://developer.blender.org/D2112
When the colliders are joined, each cell that touches them only gets
velocity contribution once. When there are multiple objects, velocities
are summed, which causes some cells to get 2x, 3x or more than the actual
object velocity.
Fix this by using the average velocity of all colliders touching a cell.
Reviewers: miikah, lukastoenne
Reviewed By: lukastoenne
Subscribers: dafassi, scorpion81, #physics
Maniphest Tasks: T43782
Differential Revision: https://developer.blender.org/D2112
As a result of other folding simplifications it may happen that
two type conversion nodes end up directly connected. In some
cases it may be possible to then remove both. A realistic case
might be an optimized out Mix RGB node used to blend vectors.
It seems it's safe to optimize when B is a float3 type
(color, vector), and A is float3 or float.
Reviewers: #cycles, sergey
Reviewed By: #cycles, sergey
Subscribers: sergey
Differential Revision: https://developer.blender.org/D2134
(Re)-setting custom normals could cause some unwanted splitting of some of them, leading
to slightly different tangent space. Simply enlarged slightly the threshold detecting
similar normals as identical ones for now, afarid this is the kind of issue that cannot
get a full complete solution for until we drop floats...
This way we can easily switch between toolkits without worrying
whether some kernel was compiled with old or new CUDA toolkit.
It's also now possible to switch machine architecture and have
proper cached kernel detected. Not as if it happens every day,
but i did such a bitness switch back in the days :)
Make 'Laplace' filter an edge filter operation, since this what it is
typically used for, and such operation does not affect the input's alpha
channel.
Reviewers: sergey, campbellbarton
Reviewed By: sergey
Differential Revision: https://developer.blender.org/D1817
The cause seems to be that despite dt_frac being computed as
1/(subframes+1) with integer subframes value, it doesn't always
add up to exactly 1.0 due to precision limitations. If the sum
is similar to 1.00000???, the last subframe is skipped, and all
particles that were supposed to be emitted in that interval are
emitted next frame, with the code working incorrectly due to
skewed time range.
To fix, separate the code from the dynamic timestep feature that
adjusts the last subframe length into a separate function, and
use it even when dynamic timestep is disabled.
Code coverage of different combinations of secondary conditions
is obviously not complete because there are so many of them, but
all main rules should be there.
The reason for CORRECT vs INVALID is that both words have the same
number of characters so calls line up, but look quite different.
Reviewers: #cycles, sergey
Reviewed By: #cycles, sergey
Subscribers: dingto, sergey, brecht
Differential Revision: https://developer.blender.org/D2130
All the changes are mainly giving explicit tips on inlining functions,
so they match how inlining worked with previous toolkit.
This make kernel compiled by CUDA 8 render in average with same speed
as previous kernels. Some scenes are somewhat faster, some of them are
somewhat slower. But slowdown is within 1% so far.
On a positive side it allows us to enable newer generation cards on
buildbots (so GTX 10x0 will be officially supported soon).
Enabled the Undo option for the operation "Add background Image". This is to treat adding a background image like opening an image. This behavior is useful when a background image is add using 'drag and drop'.
Reviewers: Severin
Reviewed By: Severin
Subscribers: brecht
Tags: #bf_blender
Maniphest Tasks: T47050
Differential Revision: https://developer.blender.org/D1725
The redundant terms were harmless but check an expression we already
know to be true (from earlier in the same conditional).
Found by PVS-Studio T48917
