This fixes some "regressions" introduced in rev50781 which lead to much
worse solution in some cases. Now it's possible to bring old behavior back.
Perhaps it's more like temporal solution for time being smarter solution is
found. But finding such a solution isn't so fast, so let's bring manual
control over reprojection usage.
But anyway, imo it's now nice to have a structure which could be used to
pass different settings to the solver.
- move object_iterators.c --> view3d_iterators. (ED_object.h had to include ED_view3d.h which isn't so nice)
- move projection functions from view3d_view.c --> view3d_project.c (view3d_view was becoming a mishmash of utility functions and operators).
- some some cmake includes as system-includes.
The Euclidean resection code had a magical constant, 1e-3, used to
compare the results of solving an equation. This failure detection
was well-intended, trying to prevent poor solutions from getting
made without notifying the caller. Unfortunately in practice, this
threshold is too conservative. Furthermore, it is not clear the
threshold should exist at all; the purpose of the Euclidean
resection is to come up with the best solution it can; other
methods (e.g. reprojection error) should be used to compare
whether the method succeeded.
This commit changes the Euclidean EPnP code to always succeed,
causing the previous fallback to projective resection to never
run. In most cases, this will result in better reconstructions.
This should, in most cases, fix the dreaded "flipping" problem.
The planar tracker uses Ceres for the refinement stage. During
refinement, Ceres iteratively updates the parameters with the
latest best guess. If the change in the parameters falls below a
threshold, Ceres will abort successfully ("converged").
For the case of pure translation tracking, the parameters are
exactly the two pixel shifts (dx, dy), and measuring the change in
these parameters gives a meaningful termination criterion.
However, for all the other parameterizations like affine, where
the parameterization involves affine parameters that have no
physical interpretation, Ceres is left with no way to terminate
the solver early. With the existing code, often many iterations
are run long after Ceres has found a solution sufficiently
accurate for all tracking needs. No one needs tracking with
a quadrillionth of a pixel accuracy; that time is wasted.
This patch extends the existing iteration callback that is passed
in to Ceres to check if the pattern has fallen out of the search
window, to also check if the optimizer has made a tiny step. In
particular, if the maximum shift of any patch corner between two
successful optimizer steps is less than a threshold (currently
0.005 pixels), the track is declared successful and tracking
is terminated.
This leads to dramatic speed increases in some cases, with little
to no loss in track quality. This is especially apparent when
tracking patches with affine or perspective motion models. For
example, on some tracking cases I tried, the iterations Ceres took
went from 50 to 3.
The planar tracker did not detect very skinny patches which have
effectively zero area and are untrackable. This adds detection and
rejection of patterns with zero area. This fixes a crash found by
during Mango production.
It was an Abort() caused by check for solver result not equal to USER_ABORT.
In some cases solver returns USER_ABORT due to BoundaryCheckingCallback
detects coordinates does not belong to image.
Somehow this callback wasn't called in previous version of Ceres and
in the same case marker was jumping. Now when the callback is called
it seems we could simply return failure of tracking without aborting
Blender.
Probably this is in fact some issue somewhere else, would double
check with Keir about this.
Such stuff better be solved in glog itself.
Should be pretty safe change since it was defined for CMake only
and AFAIR Jens wanted to get rid of this too.
This should contain real fixes for Windows, making it more robost and hopefully
faster (due to proper collection port) on that platform.
Also hack to fix Eigen alignment shouldn't be needed anymore.
Also on platforms which have got broken TR1 collections it's better to define
CERES_NO_TR1 instead of using Boost hacks. Made changes to Scons and CMake,
but can not check if this indeed works since i don't have OSX here.
As far as i remember Keir, this should be safe for our usages of ceres
and it should save noticeable amount of time and used memory when
compiling blender with libmv support.
Quick tests with tracking went smooth after this.
Added option to use Grease Pencil datablock as a mask for pattern
when doing motion tracking. Option could be found in Tracking Settings
panel.
All strokes would be rasterized separately from each other and every
stroke is treating as a closed spline.
Also added option to apply a mask on track preview which is situated
just after B/B/W channel button under track preview.
Helps keeping features tracked when there's large scale happens
without need to manually re-adjust search area.
Currently using factor of pattern's boundbox scale, but probably
could be done in more accurate way?
This patch aims to solve unaligned operation assert
happens in Eigen library.
This is short-term solution which in fact shall be reverted
as soon as real solution would be added to Ceres. Meanwhile
this should be acceptable to have for a while.
===========================================
Major list of changes done in tomato branch:
- Add a planar tracking implementation to libmv
This adds a new planar tracking implementation to libmv. The
tracker is based on Ceres[1], the new nonlinear minimizer that
myself and Sameer released from Google as open source. Since
the motion model is more involved, the interface is
different than the RegionTracker interface used previously
in Blender.
The start of a C API in libmv-capi.{cpp,h} is also included.
- Migrate from pat_{min,max} for markers to 4 corners representation
Convert markers in the movie clip editor / 2D tracker from using
pat_min and pat_max notation to using the a more general, 4-corner
representation.
There is still considerable porting work to do; in particular
sliding from preview widget does not work correct for rotated
markers.
All other areas should be ported to new representation:
* Added support of sliding individual corners. LMB slide + Ctrl
would scale the whole pattern
* S would scale the whole marker, S-S would scale pattern only
* Added support of marker's rotation which is currently rotates
only patterns around their centers or all markers around median,
Rotation or other non-translation/scaling transformation of search
area doesn't make sense.
* Track Preview widget would display transformed pattern which
libmv actually operates with.
- "Efficient Second-order Minimization" for the planar tracker
This implements the "Efficient Second-order Minimization"
scheme, as supported by the existing translation tracker.
This increases the amount of per-iteration work, but
decreases the number of iterations required to converge and
also increases the size of the basin of attraction for the
optimization.
- Remove the use of the legacy RegionTracker API from Blender,
and replaces it with the new TrackRegion API. This also
adds several features to the planar tracker in libmv:
* Do a brute-force initialization of tracking similar to "Hybrid"
mode in the stable release, but using all floats. This is slower
but more accurate. It is still necessary to evaluate if the
performance loss is worth it. In particular, this change is
necessary to support high bit depth imagery.
* Add support for masks over the search window. This is a step
towards supporting user-defined tracker masks. The tracker masks
will make it easy for users to make a mask for e.g. a ball.
Not exposed into interface yet/
* Add Pearson product moment correlation coefficient checking (aka
"Correlation" in the UI. This causes tracking failure if the
tracked patch is not linearly related to the template.
* Add support for warping a few points in addition to the supplied
points. This is useful because the tracking code deliberately
does not expose the underlying warp representation. Instead,
warps are specified in an aparametric way via the correspondences.
- Replace the old style tracker configuration panel with the
new planar tracking panel. From a users perspective, this means:
* The old "tracking algorithm" picker is gone. There is only 1
algorithm now. We may revisit this later, but I would much
prefer to have only 1 algorithm. So far no optimization work
has been done so the speed is not there yet.
* There is now a dropdown to select the motion model. Choices:
* Translation
* Translation, rotation
* Translation, scale
* Translation, rotation, scale
* Affine
* Perspective
* The old "Hybrid" mode is gone; instead there is a toggle to
enable or disable translation-only tracker initialization. This
is the equivalent of the hyrbid mode before, but rewritten to work
with the new planar tracking modes.
* The pyramid levels setting is gone. At a future date, the planar
tracker will decide to use pyramids or not automatically. The
pyramid setting was ultimately a mistake; with the brute force
initialization it is unnecessary.
- Add light-normalized tracking
Added the ability to normalize patterns by their average value while
tracking, to make them invariant to global illumination changes.
Additional details could be found at wiki page [2]
[1] http://code.google.com/p/ceres-solver
[2] http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.64/Motion_Tracker
Currently only put sources of Ceres library into extern/libmv/third_party and
setup CMake and SCons building systems.
Integration details:
- Even CMake build files are not re-used from Ceres's trunk: they're using some
automatic stuff detection like glog, pthreads, protobuf and so and it's not
so clear how to re-use that files without modifications.
And IMO it's easier if build files are getting re-generated automatically to
match Blender-specific setup rather than keeping changes made locally in
Blender in sync when re-bundling Ceres library. Especially in case when it's
already needed to support SCons build system.
- Integrated only actual sources, all tests were stripped. Probably it'll be nice
to have them, but they'll need clear integration with current module test stuff
in Blender.
- Suitesparse was disabled. It'll help a lot having it, but there are some difficulties
making cholmod working fine on windows. Would be added in future
- collections_port.cc was also stripped. It's not used by Ceres's upstream and
it gives compilation error (undefined uint32 -- looks like namespace issue).
- Currently all schur eliminators are included. Not sure if it makes sense,
also not sure if it makes sense having them switchable on and off -- IMO better
to have single configuration which works and does not require special tweaks
after everything was set up.
To bundle updated version of Ceres:
- Go to extern/libmv/third_party/ceres folder
- Run ./bundle.sh
This will checkout fresh Ceres snapshot of Windows branch (which is currently
most interesting from integration into Blender POV), apply all patches listed
in patches/series and copy needed files into Blender's working copy. This will
also re-generate CMake/SCons build rules.
If you'll need extra files from Ceres repository which are not present in
Blender, you'll need to copy them manually and then run ./mkfiles.sh from
extern/libmv/third_party/ceres folder which will update list of files used
by Blender.
Thanks to Leir Mierle and Sameer Agarwal (and all others who helped developing
Ceres) this library and thanks to Keir Mierle with help integrating it into Blender!
Expose option into interface to use modal solver which currently
supports only tripod motion.
This solver requires two tracks at least to reconstruct motion.
Using more tracks aren't improving solution in general, just adds
instability into solution and slows down things a lot.
Refirement of camera intrinsics was disabled due to it's not only
refines camera intrinsics but also adjusts camera position which
isn't necessary here
To use this solver just activate "Tripod Motion" checkbox in
solver panel.
Merged from tomato: svn merge ^/branches/soc-2011-tomato -r45622:45624 -r46036:46037
P.S. Quite experimental yet, requires more checking and probably
tweaks to prevent camera jumps when tracks apperars/disappears
from the screen.
Expose option into interface to use modal solver which currently
supports only tripod motion.
This solver requires two tracks at least to reconstruct motion.
Using more tracks aren't improving solution in general, just adds
instability into solution and slows down things a lot.
Refirement of camera intrinsics is supported by this solver.
To use this solver just activate "Tripod Motion" checkbox in
solver panel.
- Deduplicate patetrn sampling used in esm and lmicklt trackers and
move SamplePattern to image/sample.h - Move computation of Pearson
product-moment correlation into own function in new file image/correlation.h
so all trackers can use it to check final correlation.
- Remove SAD tracker. It's almost the same as brute tracker, with only two differences:
1. It does brute search of affine transformation which in some cases helps to track
rotating features 2. It didn't use common tracker api which probably gave some
speed advantage, but lead to a real headache to use it together with other
trackers leading to duplicated code in blender side.
- Switch blenedr to use brute tracker instead of sad tracker which tracking made
source code much more simple to follow.
