https://www.youtube.com/watch?v=PdSdrqhSiZA
The new geom attribute surfacevel (6 numbers: linear and angular velocity in the geom's local frame, angular about the geom frame origin) specifies the velocity of the geom's surface material relative to the geom frame. The relative surface velocity of the two geoms is added to the tangential contact rows of efc_vel in mj_referenceConstraint, so friction drives touching bodies toward the motion of the surface: objects on a conveyor are transported at belt speed, turntables impart omega x r with torsional spin-up for condim >= 4, and surface velocities compose with each other and with body motion. The component along the contact normal is projected out: probe experiments showed that velocity-space emission chatters mass-independently and ingestion merely deepens penetration; normal-direction effects belong to force-space features.
surfacevel is interpreted in the geom frame as authored: for mesh geoms, whose compiled frame absorbs the mesh centering and principal-axes transform, the compiler re-expresses the authored value in the compiled frame.
No special interaction with sleeping: objects being transported do not fall asleep because they are moving; objects at rest on an active surface may sleep like any other resting object.
Includes showcase models (model/surfacevel/): a luggage carousel whose ring is a spinning square-profile supertorus fed by a cascade of belts with matched spinning end rollers, bags dropping in and circulating indefinitely; and a treadmill with a passive humanoid.
PiperOrigin-RevId: 948647785
Change-Id: I0c6559a91cc7ece1237eb8ac2e51986e7342d962
An actuator now owns a block of consecutive controls
(actuator_ctrladr/ctrlnum, width defined by the actuator type) and a block
of consecutive force outputs (actuator_outadr/outnum, width defined by the
transmission type). Force outputs are the scalars of actuation space: one
force, length, velocity and moment row each. nout = dim(actuator_force) is
derived from transmission types; all current types have width 1, so all
three counts coincide for every existing model and behavior is bit-exact.
Array re-keying: ctrlrange/ctrllimited by nu; forcerange/forcelimited/gear/
acc0/length0/lengthrange and the moment row structure by nout; everything
else per actuator. The mjModel actuator block is re-sorted by size key.
Layout-breaking, not behavior-breaking: saved .mjb files are invalidated
(size list changed) and recompilation is required.
PiperOrigin-RevId: 948351772
Change-Id: Icbc196ffa083cb1eaa6f1a3710869c89d8f62540
The mid-phase BVH descent filter prunes body pairs using body_margin,
which was compiled as the max over geom margins, excluding gap. Broadphase
and the leaf-level test both use margin+gap, so any multi-geom body relying
on gap could silently lose its in-gap contacts when raw AABBs don't
overlap. Single-geom bodies take the leaf-leaf path and were unaffected.
PiperOrigin-RevId: 946967548
Change-Id: I6d92baa296f1a83be68b4dbfd64a96d1c7efd3c4
Compiler warnings are now accumulated in a vector of strings within the mjSpec object. New API functions `mjs_numWarnings` and `mjs_getWarning` are added to access these warnings. The compiler's log handler now chains warnings to the global log handler, ensuring they are still displayed immediately. Call sites in `mj_loadXML`, `mj_compile`, and the Python and WASM bindings have been updated to use the new warning API.
PiperOrigin-RevId: 933361650
Change-Id: I47cab98a460c57b0898c0a1a43fce2a5b9648eb1
The maximum depth of the octree used for SDF generation can now be specified in the mesh definition via `mjsMesh::octree_maxdepth`. The default value is 6.
PiperOrigin-RevId: 912494999
Change-Id: I6d828d1d3999b99d1210a6829a05b04fac591e1f
Previously specs that were attached to some parent spec would resolve its asset paths relative to the modelfiledir of the parent spec. This means path resolution would change depending on the source of the parent spec. Instead, this change makes asset file path resolution relative to the "owning spec" i.e. the spec where the asset was created.
This enables workflows such as loading a parent spec via resource provider, then loading a child spec via `from_zip` or in memory providing `spec.assets` and resolution will work as intended.
PiperOrigin-RevId: 903207910
Change-Id: Ia58020ab372a3ceadf31e804d145e2ae53d8e5f9
The `mjCOctree::ComputeSdfCoeffs` function has been replaced by `mjCOctree::ComputeSdf`. The new implementation removes the dependency on the `triangle_mesh_distance` library. Instead, it uses a provided `mjCBoundingVolumeHierarchy` to perform closest point queries on the mesh. The signed distance is computed by finding the closest triangle face via the BVH and determining the sign based on the dot product of the vector from the closest point on the triangle to the octree vertex and the triangle's normal.
Optional Laplacian smoothing has been added to the SDF coefficients. This helps smooth out potential discontinuities at octree level boundaries.
PiperOrigin-RevId: 875093374
Change-Id: I6fa53243a2dda107ccf255bc6b876ca5a4554d4f
The logic for computing Signed Distance Function (SDF) coefficients using TriangleMeshDistance is moved from `mjCPlugin::Make` in `user_mesh.cc` to a new method `mjCOctree::ComputeSdfCoeffs` in `user_objects.cc`. This encapsulates the SDF computation within the octree class.
PiperOrigin-RevId: 874572414
Change-Id: Ia2365c9c4527a252ff1d1bb43fe2c2593761e471
This change updates all size-related members within the `mjModel` struct from `int` to `mjtSize`. This allows MuJoCo to handle models with a larger number of elements. Corresponding changes were made to macros, function signatures, and I/O routines to accommodate the new `mjtSize` type.
PiperOrigin-RevId: 860144595
Change-Id: I701c6d607715d240766b6210a9773cd9e4258c59
Also, unify the meaning of fitting a geom to an AABB: it now means to find the smallest geom such that its AABB contains the mesh AABB.
Fixes#2881.
PiperOrigin-RevId: 817097544
Change-Id: I883c686feffa803bd16ba461db24a474dfec7712
This will allow assets to cache compiled results with different parameters. For example, we could cache both an RGB version of a texture and a Mono version.
PiperOrigin-RevId: 811341377
Change-Id: Ifd6a4ff88661a2b38be47c02d6a666de2c202885
For backwards compatibility in the Python bindings, both `spec.compiler.meshdir` and `spec.meshdir` are now allowed.
Fixes#2834.
PiperOrigin-RevId: 809060113
Change-Id: Ie23f1c5dd57de43568312a8e062906f4013bb474
This is done by detecting the hanging nodes and compute the function at those location by interpolating the corresponding coarse vertices.
PiperOrigin-RevId: 807700228
Change-Id: I27dcb85361ca445c2099dd07b280cae5c92d3131
This means that two adjacent nodes can only have at most one level of refinement difference.
Note: This is a small breaking change for mjWarp since the order of the children was flipped.
PiperOrigin-RevId: 806299445
Change-Id: Ia326a31c7a8162ae02d70c868d87779198e805be
The octree construction is now performed using a breadth-first search with a `std::deque` to manage tasks. A new `OctreeTask` struct encapsulates the state for each node to be processed, and a helper function `Subdivide` is introduced for subdividing the Octree nodes.
Also reduce the number of (center, size) to (min, max) conversion for the bounding box representation in order to avoid duplicated vertices in the Octree due to floating point errors.
PiperOrigin-RevId: 806214441
Change-Id: Iff9015ebe4705522db743c478cef5acf1a7312b7
Previously, it was assumed that attaching was the last operation performed on the mjSpec, so keyframes resulted in the incorrect size. In order to prevent information loss, we now only allow the resize function to expand the keyframe array, since attach should never remove a degree of freedom.
PiperOrigin-RevId: 804917828
Change-Id: Icfacd207ced1c6aac600d514f8d9065ceff2d347
This extends both the spec and the XML definition to allow specification of a material name on a mesh. This material acts as a fallback in the case that the referencing geom element does not specify a material of it's own.
PiperOrigin-RevId: 798232378
Change-Id: Iaf300c727732744ea1b613e64334ee505ac6e209
Number of octree nodes for cow example:
Before change 45217
After change 28921
PiperOrigin-RevId: 783748606
Change-Id: I278ac7bc969dc1463d6dd0f7cdc8b267b7ce6c92
Yuval Tassa