mju_boxQP documents that only the lower triangle of the Hessian H is
read, but the gradient and search-direction updates inside
mju_boxQPoption still called the dense mju_mulMatVec, which reads the
upper triangle as well. This violated the documented contract and
prevented callers from safely leaving the upper triangle uninitialized.
Add a file-local mulMatVecSym helper that computes res = H*vec while
reading only the lower triangle of H (mirroring the convention of the
existing mulVecMatVecSym quadratic-form helper), and use it in place of
mju_mulMatVec in both call sites. Extend the BoxQP test suite with
UpperTrianglePoisoned, which fills the strict upper triangle of H with
NaN and verifies that the solver produces the same result as on the
clean symmetric input.
Reported by @lshdlut.
Fixes#3275
Combine sparse vectors in-place by first counting total `nnz` and then working backwards from the end. This removes the need for temporary buffers in `mju_combineSparse` and its callers and speeds up the function by ~10%.
PiperOrigin-RevId: 902530210
Change-Id: I4f48c327103552ab968d3915399c6067367bec9f
The new symbolic function is a generalization of the function it replaces. In this CL it takes two unused temp arrays. The actual change in behavior happens in the followup.
New benchmark test output below ("L" is 2 humanoids and 100 free objects, "XL" is 100 humanoids). Note that `symbolic` is only ever called once per Newton iteration, while `numeric` is sometimes called multiple times (when the rank-1 update fails), hence timing them separately is valuable.
```
Benchmark Time(ns) CPU(ns) Iterations
--------------------------------------------------------------
BM_old_L_mean 84382 84703 19547 11.807k items/s
BM_symbolic_L_mean 16345 16381 88414 61.055k items/s
BM_numeric_L_mean 10986 10994 120000 90.999k items/s
BM_old_XL_mean 1241208 1244212 1200 803.924 items/s
BM_symbolic_XL_mean 130917 131042 12720 7.631k items/s
BM_numeric_XL_mean 77004 76767 21116 13.029k items/s
```
PiperOrigin-RevId: 846704054
Change-Id: Ib0c365724d63bf2b81606ca5353756a6496c3a26
- Preparation for a float32 build of MuJoCo.
- Fix use of `float`-typed `fabs` in `mju_eig3`.
PiperOrigin-RevId: 643804942
Change-Id: I89f64e8fd39f4e70e78d7607816283e217912383
This solves the texture rendering issue with the Rubik's cube. The texture were specified with respect to the incorrect frame, so a default rotation of (0, 0, pi/2) is now applied to the model file.
PiperOrigin-RevId: 571715153
Change-Id: I3efae3b1fc8f64e6c9e4db90a7609506e3cbed86
Since fdbbc8bbe0, mju_mulQuat allows in-place computations.
There were a few places where the result was unnecessarily assigned to a temporary variable.
PiperOrigin-RevId: 477746005
Change-Id: I7351ef4796e7d70a4a54b930037bfaadee781f12
- Before this change, an asymmetric Hessian would lead to solver failure. After this change the Hessian is symmetric by definition (upper triangle is ignored).
- API documentation was updated to reflect this contract.
PiperOrigin-RevId: 477135411
Change-Id: I60d011d36853afebac26c359771c217baf101360
Added analytic derivatives of smooth (unconstrained) dynamics forces, with respect to velocities:
- Centripetal and Coriolis forces computed by the Recursive Newton-Euler algorithm.
- Damping and fluid-drag passive forces.
- Actuation forces.
A new implicit-in-velocity integrator is implemented using the analytic derivatives. This integrator lies between the Euler and Runge Kutta integrators in terms of both stability and computational cost.
PiperOrigin-RevId: 450377010
Change-Id: Ie192b441876c22e732fb749333926f296e0a09cc
Yuval Tassa