Hauke Strasdat
Reputation
953
Top tag
Next privilege 1,000 Rep.
Create tags
 Mar10 awarded Nice Answer Dec10 awarded Caucus Oct20 comment Estimating the missing points of a 3D point cloud I fear there is not enough information to provide an answer. How was point cloud generated in the first place? Uniformly sampled from a perfect 3d model? Or noisy measurements from a 3d sensor? Even if you don't have prior know of the original shape, you might have some knowledge of the smoothness or topology of the surface? Sep11 awarded Yearling Jul2 awarded Curious Jun7 answered Any name for a special matrix with only non-zero entry May29 comment Jacobian of exponential mapping in SO3/SE3 I think you are right, and the equation $\partial \frac{e_i(\omega)}{\partial \omega_k} = \exp(\omega)\cdot G_k$ is wrong. But why do you think: $e_i(\omega)=\exp(\omega)$ The comment you mentioned states $\partial \frac{\exp(\omega)}{\partial \omega_k} = \exp(\omega)\cdot G_k$, but not $\partial \frac{\exp(a_i\log(\exp(\omega)T))P_i-P_i^*}{\partial \omega_k} = \exp(\omega)\cdot G_k$. Apr11 awarded Revival Dec31 comment Optimization Problem - a rod inside a hallway Sorry, this is no help. But this problem is somehow related to the hard "moving sofa" problem, so I thought I provide a link: math.stackexchange.com/questions/533436/… Dec9 revised Can axis/angle notation match all possible orientations of a rotation matrix? edited body Nov29 revised Curves with “constant speed”? clarification Oct25 comment How do “proofs” work in mathematics, down to the basic level? @Cuc $1+2+4+6+8$ can be a statement depending on the definition of the symbols. Sorry, I could not resist! Oct23 answered Getting started with Lie Groups Oct20 revised Curves with “constant speed”? edited tags Oct19 comment Quaternions as group of rotation and scaling Well yes, scaling and rotations commutes. And if we analyzed rotation, the direct product of rotation and scaling is trivial. But on the other hand, complex numbers are often discussed using polar coordinates (rotation and scaling), and here we don't usually focus on unit complex numbers only. Oct19 revised Curves with “constant speed”? deleted 3 characters in body; edited title Oct18 revised Curves with “constant speed”? edited title Oct18 asked Curves with “constant speed”? Oct1 comment Speeding up the convergence for Steepest Descent Method In general, the gradient does not point in the right direction, e.g. if you look at cs.cmu.edu/~quake-papers/painless-conjugate-gradient.pdf, Fig. 17. Actually, in this particular case, I guess a factor smaller one would help, more like Ritalin than espresso. Sep30 comment Confusion related to derivative of a vector Well wikipedia says the Jacobian is written as $\frac{\partial (F_1, ..., F_m)}{\partial (x_1,...,x_n)}$ and this is just the special case for the constant function with $F=\theta$ and $x=\theta$. To be very precise, we probably have to transpose one of the two $\theta$'s...