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Mujoco_WASM/plugin/elasticity/shell.h
T
Alessio Quaglino d67b8c6251 Add membrane plugin (2D Flex elastic stiffness).
PiperOrigin-RevId: 574109411
Change-Id: I4a701d8189cecf540cd200bd30cb4582f3c7dd43
2023-10-17 04:55:33 -07:00

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C++

// Copyright 2023 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.
#ifndef MUJOCO_PLUGIN_ELASTICITY_SHELL_H_
#define MUJOCO_PLUGIN_ELASTICITY_SHELL_H_
#include <optional>
#include <vector>
#include <mujoco/mjdata.h>
#include <mujoco/mjmodel.h>
#include <mujoco/mjtnum.h>
#include "elasticity.h"
namespace mujoco::plugin::elasticity {
struct StencilFlap {
static constexpr int kNumVerts = 4;
int vertices[kNumVerts];
};
class Shell {
public:
// Returns a new Shell instance or nullopt on failure.
static std::optional<Shell> Create(const mjModel* m, mjData* d,
int instance);
Shell(Shell&&) = default;
Shell& operator=(Shell&& other) = default;
void Compute(const mjModel* m, mjData* d, int instance);
static void RegisterPlugin();
int i0; // index of first body
int nc; // number of quads in the grid
int nv; // number of vertices (bodies) in the Shell
int nt; // number of area elements (triangles)
int ne; // number of edges in the Shell
// connectivity info for mapping tetrahedra to edges and vertices
std::vector<Stencil2D> elements; // triangles (nt x 6)
std::vector<StencilFlap> flaps; // adjacent triangles (ne x 4)
// precomputed quantities
std::vector<mjtNum> position; // previous-step positions (nv x 3)
std::vector<mjtNum> bending; // bending Hessian (ne x 16)
mjtNum thickness;
private:
Shell(const mjModel* m, mjData* d, int instance, mjtNum nu, mjtNum E,
mjtNum thick, const std::vector<int>& face,
const std::vector<int>& edgeidx);
void CreateStencils(const std::vector<int>& simplex,
const std::vector<int>& edgeidx);
};
} // namespace mujoco::plugin::elasticity
#endif // MUJOCO_PLUGIN_ELASTICITY_SHELL_H_