mierle

9 ms·

31.
by mierle 14y ago
Both RProp and Conjugate Gradient are descent methods-- they find a path to a local minima from the starting configuration. They do not help with finding the global minimum. Using simulated annealing to guide random initializations can help
32.
Fourth Blender open source movie Tears of Steel released(tearsofsteel.org)
3 points by mierle 14y ago|0 comments
33.
by mierle 14y ago
The roads are not an input to the optimization shown in the examples. How this works is left as an exercise for the reader.
34.
by mierle 14y ago
I forgot an important technique that is somewhere between numeric differentiation and automatic differentiation: (4) Complex-step differentiation http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.141.... The technique is clever: the
35.
by mierle 14y ago
Done!
36.
by mierle 14y ago
Working on integrating fixes now...
37.
by mierle 14y ago
I've wondered the same myself. It's rather popular in industry. I hadn't head of it until coming to Google. Fun fact: backpropagation for neural networks, which is really just a fancy word for computing the derivatives of the cost, is equiv
38.
by mierle 14y ago
Automatic differentation is "symbolic" in the sense that the resulting derivatives are exact, in the same way that you get exact derivatives if you differentiate by hand and implement the resulting expression. There is no approximation. Num
39.
by mierle 14y ago
No, this is not true. Autodiff != numeric diff. While we do support numeric differentiation, we don't suggest you use it. What we have is automatic differentiation, which is a technique to take exact derivatives without resorting to symbo
40.
by mierle 14y ago
Fusing sensor data (IMU, etc). You can formulate this as a (extremely) giant sparse least squares problem.
41.
by mierle 14y ago
Unfortunately we can't talk much about this; sorry.
42.
by mierle 14y ago
Blender got integrated matchmoving / tracking with the 2.61 release, by way of libmv (which I am the BDFL of). A critical part of many tasks in 3D reconstruction and tracking is a solid, flexible nonlinear minimizer. Since Ceres is so easy
43.
by mierle 14y ago
It's not just expressions; it's any computation you normally would do with doubles. Take a look at the simple bundle adjustment example: http://code.google.com/p/ceres-solver/source/browse/examples... In particular, search for "SnavelyRep
44.
by mierle 14y ago
There's some more discussion over at Reddit: http://www.reddit.com/r/programming/comments/t1mo7/ceres_sol...
45.
by mierle 14y ago
Took long enough but we finally made it!
46.
by mierle 14y ago
This is a key component of Street View. We're really happy to have released this. When we started writing Ceres, there was nothing available like it. It's state of the art; a real contribution to computer vision and other fields which need
47.
Google open sources key piece of Street View technology(google-opensource.blogspot.com)
350 points by mierle 14y ago|51 comments
48.
by mierle 15y ago
I'd love to make a blog post but doubt I will have time. I tend to prioritize coding over writing, even though that is not always the best choice.
49.
by mierle 15y ago
It feels great to finally get this shipped, so thanks! There's no question that the workflow inside Blender is not optimal. Fixing this is planned for the 2.62 release. If you have specific suggestions on what you were expecting vs what was
50.
by mierle 15y ago
Hi guys, I'm the primary developer of libmv ( http://libmv.googlecode.com ) which is used for the motion tracking component in Blender. I also wrote some of the Blender-specific motion tracking code. What's in this release is not the final