mju_factorLU6/mju_solveLU6: same algorithm as mju_factorLU/mju_solveLU
with compile-time size, allowing full unrolling. At n=6, factor+solve is
25% faster than the runtime-sized version (93 vs 124 ns), and fixed-size
LU factorization is faster than generic dense Cholesky (55 vs 61 ns):
at this size, runtime-n loop overhead outweighs Cholesky's 2x flop
advantage. See new lu_benchmark_test. Results agree with the generic
version to rounding, not bitwise: the compiler may fuse (FMA) the
unrolled version differently.
Also add two DenseLU tests: a pivoting-required matrix with zero
diagonal, and fixed-vs-generic agreement.
PiperOrigin-RevId: 947705056
Change-Id: I24c54c9510964aa376886e9dd721890eda9889d3
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
Reformulate the cost difference calculation (`ellipticCostDif`) to use mathematically equivalent formulas that avoid subtracting large, nearly equal values (cancellation errors) in single precision at high normal forces.
This is a C port of Alain's formulation in MJWarp:
https://github.com/google-deepmind/mujoco_warp/pull/1512
Also adds an integration test (`EllipticLineSearchPrecisionDiagnostics`) that reproduces the precision issue under large normal forces in the sliding regime, and asserts that the solver does not produce large negative improvements in either precision. This test failed before the change.
PiperOrigin-RevId: 946137815
Change-Id: Ia8fc1c4823b5fee770140c8989b9465737d22ad7
The code for the timeline scrubber widget has been moved from `App::ModelOptionsGui` into a new method `App::TimelineScrubberGui`. This new method is now called in both `App::ModelOptionsGui` and `App::ToolBarGui`, replacing the thread count slider in the toolbar.
PiperOrigin-RevId: 945565640
Change-Id: I6d5cab0b2397e8b32a2b335e8a709bb9e19bdb48
Extend mjpResourceProvider with an optional write callback (write)
so that mj_encode, mj_saveXML, and mj_saveModel can write to any
registered provider.
PiperOrigin-RevId: 945202741
Change-Id: I37903425260932e555f4a8c2392c4ff8c2e6cc06
Introduces a new timeline widget in the Studio UI, replacing the previous integer slider for simulation history. The new widget displays the current and maximum simulation times, formatted with appropriate units (µs, ms, s), alongside the actual step number, and allows scrubbing through the history via a custom-drawn spine and knob.
This change also modifies the history recording logic to record every solver step rather than only every rendered frame. This enables the step forward/backward buttons to navigate exactly 1 solver step at a time.
This change also fixes `SimHistory::SetIndex()` range checks in `sim_history.cc` to clamp `offset_` against `1 - size_` (`Size()`) rather than total vector capacity (`history_.size()`).
PiperOrigin-RevId: 944671699
Change-Id: Iaa34668a1e257e5c0c1840c827370d81c4935b3d
The flexcomp compiler previously rejected pins on dim-2 flexes with
bending (elastic2d bend/both). Allow them: mj_flexPassiveBend treats a
pinned vertex (body without 3 free slide dofs) as static -- zero
velocity, and no bending force applied to it (the reaction is carried
by the pin) -- while its position still enters every neighbor's
bending force, which is exactly what the pin constrains.
PiperOrigin-RevId: 944410969
Change-Id: Ib0a69c8d5fb6f64d3e2a76af3b6b2c7be1898191
Testing on 50 million random doubles we have branchless clip is 1.14x faster than the branched version and branchless sign is 2.27x faster than the branched version.
PiperOrigin-RevId: 943812426
Change-Id: If8003a602365601a31bec1d8b080c44d16000a4e
This example demonstrates how to use Studio's `extra_geoms` feature to render semi-transparent, time-delayed copies of the model's geoms, creating a "ghost" effect.
PiperOrigin-RevId: 943672439
Change-Id: I8ae640672945b55dd25dd3d444f52d0b2fa7f0f8
ViewerApp is simplified, interacting with the endpoint and handlers through the Viewer instance. This change makes it possible to write simulation viewers without using the UI/UX provided by ViewerApp (which should be renamed StudioApp)
PiperOrigin-RevId: 943642660
Change-Id: Id8eb3d4e6a27ceda93833367fec4699fa6bc838e
There is a single remaining exception for mjb as it's a special case by bypassing mjSpec.
PiperOrigin-RevId: 943556676
Change-Id: Iaf480ea6d2d42a6007b35c23435b25c9eb24ead0
On Windows, std::filesystem::path::string() returns backslashes while
zip entries use forward slashes. This caused lookup mismatches making
MJZ decoding fail on Windows with 'could not decode content'.
Use generic_string() (which always returns forward slashes) for all
path operations used in zip entry lookups, and normalize the archive
name at construction time.
PiperOrigin-RevId: 943538265
Change-Id: I50cafff82fd7f5f315ccfc890f660e138e4448a2
Kyle Bayes