Resource operations (e.g. mju_openResource, mju_readResource, and
mju_closeResource, etc.) are now all handled by a VFS instance. It
is now up to the VFS to determine which provider to use in order to
handle those operations.
This allows us to dynamically add/remove (aka "mount") providers to
a VFS to handle special requests. mj_addFileVFS and mj_addBufferVFS
have been reimplemented as two such use-cases. Moreover, we expose
the mounting behaviour with two new functions: mj_mountVFS and
mj_unmountVFS.
PiperOrigin-RevId: 856166919
Change-Id: Id723d612ffc0bff020705cf19ef95fbf24676840
Regarding mj_compile VFS argument:
I was encountering a memory error when using `std::optional<MjVFS>` with `mj_compile` (because vfs should be an optional argument of the function). This is likely because `MjVFS` doesn't have copy/move constructors, which are required for types used with `std::optional`, causing issues with memory management when std::optional copies the MjVFS object.
To solve this and to make vfs an optional argument to `mj_compile`, I replaced `mj_compile_wrapper` with two overloaded functions. This avoids using `std::optional<MjVFS>` and resolves the memory issue, while still allowing mj_compile to be called with or without the vfs argument from JavaScript.
But what if we instead add those copy/move constructors so it works with `std::optional`?:
While making `MjVFS` copyable or movable would theoretically allow it to work with std::optional, it's not a feasible approach in this case.
The MjVFS struct manages file data in memory, allocating buffers when files are added and freeing them when `mj_deleteVFS` is called in its destructor. A copy would require a deep copy of the entire virtual filesystem, but MuJoCo does not provide a public API function (like a "mj_copyVFS") to do this. Implementing a deep copy manually would be complex and fragile. A shallow copy would result in multiple MjVFS objects pointing to the same memory, leading to double-free errors when their destructors run.
Given these constraints, MjVFS cannot safely be made copyable. The approach of providing two overloaded C++ functions is better.
PiperOrigin-RevId: 855740541
Change-Id: Ia08b6db8868ad245f07145db3fb0322cb9f737cb
All known implementations were effectively the same as the default fallback. It was just adding unneeded complexity. Removing this now will help with upcoming improvements to resource providers.
PiperOrigin-RevId: 855163273
Change-Id: I529fc18d0d03a8dc676c909ec9e4b1da1454d414
This allows calling `mujoco.mj_copyData(dest, model, src)` to copy data between existing `mjData` instances.
PiperOrigin-RevId: 855150139
Change-Id: If122cb7acf590846e25ee15f9770c3c087147169
Updates function comments to consistently use a semicolon (`;`) before describing the return value and to use the imperative form "return" instead of "returns".
Also fix error in docstring of `mjp_registerResourceProvider`
PiperOrigin-RevId: 854888532
Change-Id: I311239a2770ded5febece9958ae4e94c1e522600
Add usd_decoder to mujoco/plugin.
- Previously was src/experimental/usd/usd_to_mjspec.cc, now that same spec is returned by the plugin.
PiperOrigin-RevId: 854350962
Change-Id: Ia980190a557c50ce8197980922a2594b613859b4
Explicitly free allocated memory for local resources. (Upcoming
changes to `mju_closeResource` will not work for local resources.)
PiperOrigin-RevId: 854254013
Change-Id: I5cbb8264b590327767d5500f0c2a32ebe036bc4f
When compiling with threading, we will block the main thread anyways waiting for all threads to complete.
PiperOrigin-RevId: 854230560
Change-Id: Ief689d381afaa3aacc5d712a8df0cb4b6762251c
This allows us to remove the special "LoadModelFromString" resource provider.
PiperOrigin-RevId: 854207845
Change-Id: I6d00f2ab99b4351866e1d39dbeed96f29aaaf915
This removes the need for a custom mjResourceProvider, but does require
reimplementing part of mj_loadXML in the fixture.
PiperOrigin-RevId: 854170820
Change-Id: Ib455cc5cdb5138213eb7e996dc32ac156f22a859
This attribute allows specifying the intended output types (e.g., RGB, depth, normal) for each camera in the XML. The output types are stored as bit flags in `mjModel`.
PiperOrigin-RevId: 853316261
Change-Id: I1ad2e94102593cf402756f8f4c80509371ca86d2
Yuval Tassa