Files
Mujoco_WASM/src/experimental/usd/writer.cc
T
Sam Haves afc35451a0 Expose ability to go from USD stage to MjSpec.
PiperOrigin-RevId: 776184388
Change-Id: I0325b347c9896183d148a196897e1e5d0c4bbde2
2025-06-26 10:09:55 -07:00

69 lines
2.0 KiB
C++

// Copyright 2025 DeepMind Technologies Limited
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <mujoco/experimental/usd/writer.h>
#include <utility>
#include <vector>
#include <mujoco/experimental/usd/utils.h>
#include <mujoco/mujoco.h>
#include <pxr/usd/sdf/path.h>
#include <pxr/usd/usd/common.h>
namespace mujoco {
namespace usd {
// Writer is the main entry point for mj_usd. It is responsible
// for converting the USD scene into a Mujoco model and exposing stepping
// API.
Writer::Writer(pxr::UsdStageRefPtr stage, mjSpec* spec, mjModel_* model)
: stage_(stage), spec_(spec), model_(model) {
BuildMjUsdMapping();
}
Writer::~Writer() = default;
void Writer::BuildMjUsdMapping() {
body_id_to_path_.assign(model_->nbody, pxr::SdfPath());
// World body (ID 0) maps to an empty SdfPath.
if (model_->nbody > 0) {
body_id_to_path_[0] = pxr::SdfPath();
}
// Iterate over MuJoCo body IDs from the mjModel.
for (int body_idx = 1; body_idx < model_->nbody; ++body_idx) {
const char* body_name = mj_id2name(model_, mjOBJ_BODY, body_idx);
if (body_name) {
mjsBody* spec_body = mjs_findBody(spec_, body_name);
body_id_to_path_[body_idx] =
mujoco::usd::GetUsdPrimPathUserValue(spec_body->element);
}
}
}
void Writer::Update(const mjData* const data) {
for (const auto& sink_fn : pose_sinks_) {
sink_fn(data, body_id_to_path_);
}
}
void Writer::AddSink(PoseSinkFn sink_fn) {
pose_sinks_.push_back(std::move(sink_fn));
}
} // namespace usd
} // namespace mujoco