This change introduces `nflexstiffness` and `flex_stiffnessadr` to allow flex stiffness matrices to have sizes other than the fixed 21 per element. Higher-order flexes can now store larger stiffness matrices based on their number of nodes. The `flex_stiffnessadr` array provides the starting index for each flex's stiffness data within the `flex_stiffness` array.
PiperOrigin-RevId: 899632263
Change-Id: Ie49182c46c3777acf0c6b492345edfcf62fb5e44
Repro instructions (note compiler cache and threading must be enabled):
Assume we have a cube.stl mesh containing face data and the following XML:
<mujoco>
<asset>
<mesh name="cube" file="cube.stl"/>
<mesh name="unused" file="cube.stl"/>
</asset>
<worldbody>
<geom type="mesh" mesh="cube"/>
</worldbody>
</mujoco>
Suppose Thread A processes "cube" and Thread B processes "unused". Thread A will generate the mesh hull and will generate polygon data from faces from qhull. Thread B will NOT generate the mesh hull and will generate polygon data from faces coming from mesh file. Thread A beats Thread B to caching the mesh.
When "unused" is later pulled from the cache it gets the polygon data that was generated from "cube" which is not the same that was generated from "unused".
PiperOrigin-RevId: 878336494
Change-Id: I275b09b44490c54b2a5f09d91d0cc047026090f2
The `mjCOctree::ComputeSdfCoeffs` function has been replaced by `mjCOctree::ComputeSdf`.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
This change introduces methods to cache and load the computed stiffness matrix and nodal masses for flex elements. The cache key is generated based on material properties (Young's modulus, Poisson's ratio), interpolation order, and the bounding box of the flex. This avoids redundant expensive computations when compiling models with identical flex definitions.
PiperOrigin-RevId: 874689771
Change-Id: I6d1e299baf294a984b507e2a2602b2c068610536
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
Fix a crash and dimension mismatch issue in user_flexcomp when dealing with interpolated="true" meshes that contain unused vertices. Previously, vertbody would correspond only to used vertices while vert included all vertices, leading to assertions or out-of-bounds access. Also enable node pinning for interpolated meshes.
PiperOrigin-RevId: 865881995
Change-Id: Id150f00f22b5f48896ffbffddf03c57b252de8c0
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 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
Also disables mesh reorientation for meshes autogenerated with marching cubes from analytic SDFs.
PiperOrigin-RevId: 781487195
Change-Id: I36b66384f240a764823c489f78f22ba9fe32f15f
Temporary changes to the octree:
- Changed frame from mesh to geom
Before change (tolerance 1e-3):
```
Simulation time : 2.34 s
Steps per second : 4275
Realtime factor : 8.55 x
Time per step : 233.9 µs
Newton iters / step : 2.26
Contacts / step : 3.69
Constraints / step : 14.76
Degrees of freedom : 12
Dynamic memory usage : 0.7% of 14M
```
After change (6 octree levels):
```
Simulation time : 2.24 s
Steps per second : 4472
Realtime factor : 8.94 x
Time per step : 223.6 µs
Newton iters / step : 2.47
Contacts / step : 3.37
Constraints / step : 13.49
Degrees of freedom : 12
Dynamic memory usage : 0.2% of 14M
```
PiperOrigin-RevId: 781019754
Change-Id: Ib15581244dfe9e571e1c6c2cac4a101cf3d8ba3d
Alessio Quaglino