If given two non-decreasing values, `springlength` specifies a deadband for spring stiffness, inside of which the force is 0 and outside of which force behaves like a regular spring, with the setpoint corresponding to the nearest value. This can be used to create tendons whose limits are enforced by springs rather than constraints, which are cheaper and easier to analyse. See test/engine/testdata/tendon_springlength.xml example model.
Spring-limited spatial tendons whose lower range value is 0 are rendered as catenaries.
Fixes#520.
PiperOrigin-RevId: 484509706
Change-Id: I6698e94ee36168f52d501e83057559805e05172d
- `gain` was not inherited, either from `<adhesion gain>` default or from `<general gainprm>` default.
- `dyntype` was not inherited from `<general dyntype>` default.
- Reported by @vaxenburg.
PiperOrigin-RevId: 480707156
Change-Id: I0160531d48186e7658952e72923ceb6cb034be9b
- 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
- Add private function `mj_arenaAlloc`. This is used internally to allocate memory from the arena.
- Add private function `mj_nefc` to count constraints. This function returns a tight upper bound on `d->nefc`. The number of counted constraints can be slightly bigger than exact `d->nefc` in the case of constraints with empty Jacobian, as when placing a frictional tendon between two world sites.
- Add new `memory` attribute to the `size` XML element for specification of arena memory size. This attribute is mutually exclusive with `nstack` and `njmax` specifications, which are now deprecated (but left around for the time being for legacy compatibility).
- Move `d->stack` to the end of the new arena space. The stack now grows in reverse from the end.
PiperOrigin-RevId: 479341539
Change-Id: Ie019c202e0908577ffc6f833a37920858116f667
- Adhesion actuator defaults were not parsed, now fixed.
- Both damper and adhesion actuators were requiring `ctrlrange` at parse time, which prevented this attribute from being inherited from defaults, now fixed.
- Added tests for all 3 cases.
PiperOrigin-RevId: 475145255
Change-Id: I8dd6196e20734136d990f522893ebd4d156cd7a8
This lets the compiler catch the mistake of creating an exception without throwing it.
PiperOrigin-RevId: 474536776
Change-Id: I5bd18258ce6ddd266adb1c852b1ba9e3063cd0b2
This is an amendment to 4bfc2c0311.
Add an autolimits compiler option. When true, *limited will be inferred from the presence of the *range attributes.
When false, models where limited is not specified, and range is will fail to compile.
PiperOrigin-RevId: 472438650
Change-Id: I489098e879ee695030f44e0d8cd969787e75fb90
- Added `refsite` attribute to actuators with `site` transmission.
- Such actuators now have a well defined length and can be used for e.g., Cartesian end-effector control.
- Added example models and documentation describing the new feature.
PiperOrigin-RevId: 471561218
Change-Id: I538f09af9600d5c53992c4a9fed325648aab4fa3
- `anchor` determines the point of wrench application, in the frame of body2.
- `tfratio` scales applied torques relative to applied forces.
- Add visualisation of both anchor points to both weld and connect constraints.
- Add a test model showing how the new weld parameters behave.
PiperOrigin-RevId: 470021901
Change-Id: I3faba0e5dcab2e29ee81096f5ff71ff66d99758c
- `anchor` determines the point of wrench application, in the frame of body2.
- `tfratio` scales applied torques relative to applied forces.
- Add visualisation of both anchor points to both weld and connect constraints.
- Add a test model showing how the new weld parameters behave.
PiperOrigin-RevId: 469228149
Change-Id: I836b0791f10fb624607a12ef3c687da991c21789
- `anchor` determines the point of wrench application, in the frame of body2.
- `tfratio` scales applied torques relative to applied forces.
- Add visualisation of both anchor points to both weld and connect constraints.
- Add a test model showing how the new weld parameters behave.
PiperOrigin-RevId: 469190483
Change-Id: I20f6da85b09cd2c4c0b5d29eb8003eabb524e55e
* If output file exists, ask user whether to overwrite
* Fix erroneous check for whether XML file was successfully saved
PiperOrigin-RevId: 468743682
Change-Id: I06058c498328d333792e4b40d65c3a99ca1842e4
- `distance` constraints were not very useful and increased the contact buffer within the constraint solver, violating a core design principle. Therefore they have been removed.
- The enum value `mjEQ_DISTANCE` is retained, but errors will be thrown in the parser and engine if these constraints are selected.
PiperOrigin-RevId: 467050101
Change-Id: Ie72a07e4fe338eea5107004a9fc0f5e47eb0c3b7
- 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
- Mesh inertias can now be computed exactly for well-formed (no holes) non-convex meshes.
- To activate this feature, set `<compiler exactmeshinertia="true">` (defaults to `false`). This default may change in the future.
- Added `<geom shellinertia="true/false">` (defaults to `false`). When true, geom inertia is computed assuming all the mass is concentrated on the surface, and `density` is interpreted as surface density (mass/area). Currently only mesh geoms are supported.
PiperOrigin-RevId: 464368395
Change-Id: I17afd99b9b221c9d24ae951f6e63d5c61ff89820
- Add basic test for keyframes.
- Add missing documentation for keyframe mocap positions and quaternions.
PiperOrigin-RevId: 459021649
Change-Id: I91cf7ecbddc6262e8c72a868eeb82d627f389fb3
The C++ standard library `std::istringstream` is not guaranteed to parse "inf" and "nan" as valid floating point numbers. In our testing, libc++ does this, but libstdc++ and MSVCRT do not.
PiperOrigin-RevId: 455435431
Change-Id: I99c00303b08c2e4e62acfa3ca52a21a3008f4545
Somehow tests load these libs twice, and construct/destruct globals twice.
Can be preproduced even without sanitizers with logging from GlobalModel::~GlobalModel.
themodel does not need to be visible. If it's static each instance will have own a copy.
_mjMap does not need to use string and avoid lifecycle issues at all.
PiperOrigin-RevId: 454678814
Change-Id: I8fca5e1f06cbc2b413beabcece1219445482c0ed
Using fabs with int arguments broke the clang build on GitHub Actions, with a `-Wabsolute-value` error.
PiperOrigin-RevId: 453872474
Change-Id: I5c1278e9e628b0ea3d6f26c7ee7d6925c6276850
- Applies to [orientation specifiers](https://mujoco.readthedocs.io/en/latest/modeling.html#frame-orientations) in `body`, `inertial`, `geom`, `site`, `camera`.
- Before this change the check was done only for multiple *alternative* specifiers, but not for `quat` and an alternative specifier.
- Moved the check from the compiler to the parser.
- Added tests.
PiperOrigin-RevId: 453201981
Change-Id: I20907361f211dae904e734cd083e9df0efe4f654
Fixes a bug introduced in CL/432455486, which stopped saving explicit inertias if they were inferred from geoms. But if we don't save inertias then we need to save mass/density specifiers.
BEGIN_PUBLIC
xml_native_writer saves geom mass or density, if specified.
END_PUBLIC
PiperOrigin-RevId: 450667775
Change-Id: Ibb5b269b58f1143013091729642bb501243ed943
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
Kyle Bayes