Also:
- Renamed recently introduced `mjvPerturb` member `reflocalpos` -> `refselpos` and corrected docstring.
- Added `mjvPerturb.localmass`: body spatial inertia at selection point.
- Removed `const` qualifier to `mjData` argument of `mjv_initPerturb()`, to facilitate spatial inertia computation.
- Improved `mj_Object{Velocity, Acceleration}` docstrings, clarifying that rotational velocities precede linear velocities.
- Removed redundant const qualifiers from non pointer arguments to `mju_dot` and `mju_writeNumBytes`.
PiperOrigin-RevId: 511002168
Change-Id: I27400f497947f330072d4abb7c9bf7e71e6c5d49
- Also change signatures of `mju_fill` and `mju_symmetrize` to conform to standard.
PiperOrigin-RevId: 485613824
Change-Id: I8dd618bac92ef40aa6c76380fa73302e81968687
- Added new `cable` composite type:
* The `initial` parameter specifies the joint at the starting boundary: `free`, `ball`, or `none`.
* The boundary bodies are exposed with the names:`B_left` and `B_right`.
* The vertex initial positions can be specified directly in the XML with the parameter `vertex`.
* The orientation of the body frame **is** the orientation of the material frame of the curve.
- Added new `cable` passive force plugin:
* Twist and bending stiffness can be set separately with the parameters `twist` and `bend`.
* The stress-free configuration can be set to be the initial one or flat with the flag `flat`.
* New cable example showing the formation of plectoneme.
* New coil example.
* New belt example showing interaction between twist and anisotropy.
* Added test using cantilever exact solution.
PiperOrigin-RevId: 480033694
Change-Id: I491271bce8fccb185961477e903e5a72d172c8a3
- 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
- Add `azimuth` and `elevation` to `visual.global`.
- Add `mjv_defaultFreeCamera`.
- Use `mjv_defaultFreeCamera` in `simulate`.
PiperOrigin-RevId: 465505244
Change-Id: I61e60f14a990d4e2d220958adb75c325001978ee
- Adhesion actuators using contact normals as force transmission mechanism.
- Related video: https://youtu.be/HdBue4MUZysCloses#229
PiperOrigin-RevId: 464389367
Change-Id: I9f69b3cd152d957e8f65870d208788463c036a6d
- Add sections about the state and derivatives to the Computation chapter.
PiperOrigin-RevId: 459032736
Change-Id: I0b69401688f24c84d5747f1b49980e38e19a54a3
- Never modify `d->ctrl`:
- `ctrl` values which are outside their respective `ctrlrange` are clamped internally, but `d->ctrl` itself is unmodified.
- Similarly, if `mjWARN_BADCTRL` is raised (NaNs or huge values), `ctrl` is cleared internally, but `d->ctrl` itself is unmodified.
- `mjWARN_BADCTRL` is no longer raised for `d->ctrl` values that are larger in absolute value than `mjMAXVAL`, if clamping makes them smaller than that.
- Added `mju_clip()` utility function.
- Added missing warning string for `case mjWARN_BADCTRL`.
PiperOrigin-RevId: 459025950
Change-Id: Ifbf974f9c02c3d70afdaa3114018fc81dfd746d3
- Add `qH` and `qHDiagInv` to `mjData` to save factorized modified inertia.
- Add `mj_EulerSkip`, `mj_implicitSkip`, to `engine_forward.c`.
- Using the above functions, implement `mj_stepSkip` in `engine_derivative.c`.
- Add `mjd_stepFD` and `mjd_transitionFD` to `engine_derivative.c` to compute `mj_step` Jacobians.
- Exploit "Skip" functionality for speed.
- Correctly handle quaternion derivatives.
- Handle warmstarts and control limits.
PiperOrigin-RevId: 456584811
Change-Id: Iee8541f11e7b66feb8f431cb102d9bbe65461f79
The introduction of additional mjData arrays for the implicit integrator caused in a shift in data alignment in memory. In certain combinations of machines and models, this change resulted in ~5% performance regression that appears to be attributable to L2 cache misses.
This change aligns all arrays in mjData to the boundary of a typical L2 cache line size. Benchmarking shows that this resolves the performance regression on a Broadwell machine.
PiperOrigin-RevId: 451652783
Change-Id: I4ed2c2d03453a83a0b4a9b8e224e2fd7c0dadea9
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
This commit requires a new binary build, and therefore breaks compatibility with version 2.1.3.
Fixes#217.
Change-Id: I1e08b6fd2c468e3845e2166a1e4cc9d265de64de
This is useful when writing or modifying collision functions, when the actual direction of the x and y axes of a contact can be important.
PiperOrigin-RevId: 437256700
Change-Id: I5eab737fc98018399e151552778c6109088bf614
Yuval Tassa