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C++ TwoDScene::accumulateGradU方法代码示例

本文整理汇总了C++中TwoDScene::accumulateGradU方法的典型用法代码示例。如果您正苦于以下问题:C++ TwoDScene::accumulateGradU方法的具体用法?C++ TwoDScene::accumulateGradU怎么用?C++ TwoDScene::accumulateGradU使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在TwoDScene的用法示例。


在下文中一共展示了TwoDScene::accumulateGradU方法的2个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C++代码示例。

示例1: stepScene

bool LinearizedImplicitEuler::stepScene( TwoDScene& scene, scalar dt )
{
  VectorXs& x = scene.getX();
  VectorXs& v = scene.getV();
  const VectorXs& m = scene.getM();
  assert(x.size() == v.size());
  assert(x.size() == m.size());

  // Implement implicit euler here!
	VectorXs F(x.size());
	F.setZero();
	scene.accumulateGradU(F, dt*v, VectorXs(x.size()).setZero());
	// Force is negative the energy gradient
	F *= -1.0;

	MatrixXs M(x.size(), x.size());
	M.setZero();
	for (int i=0;i<x.size();i+=2) {
		M(i, i) = m[i];
		M(i+1, i+1) = m[i+1];
	}
	MatrixXs MatQ(x.size(), x.size());	// dF/dq
	MatQ.setZero();
	scene.accumulateddUdxdx(MatQ, dt*v, VectorXs(x.size()).setZero());
	MatrixXs MatV(x.size(), x.size());	// dF/dv
	MatV.setZero();
	scene.accumulateddUdxdv(MatV, dt*v, VectorXs(x.size()).setZero());
	MatrixXs A = M-(dt*dt*MatQ+dt*MatV);
	// Zero the force for fixed DoFs
	for( int i = 0; i < scene.getNumParticles(); ++i ) if( scene.isFixed(i) ) F.segment<2>(2*i).setZero();
	for( int i = 0; i < scene.getNumParticles(); ++i ) if( scene.isFixed(i) ) {
		A.row(2*i).setZero();
		A.row(2*i+1).setZero();
		A.col(2*i).setZero();
		A.col(2*i+1).setZero();
		A(2*i, 2*i) = 1;
		A(2*i+1, 2*i+1) = 1;
	}
	VectorXs dv = A.fullPivLu().solve(dt*F);
	v = v+dv;
	x = x+v*dt;
  
  return true;
}
开发者ID:js4768,项目名称:4167T1M3,代码行数:44,代码来源:LinearizedImplicitEuler.cpp

示例2: stepScene

bool ExplicitEuler::stepScene( TwoDScene& scene, scalar dt )
{
    VectorXs& x = scene.getX();
    VectorXs& v = scene.getV();
    const VectorXs& m = scene.getM();
    // if( scene.isFixed(i) )  // Determine if the ith particle is fixed

    int num_particles = scene.getNumParticles();
    VectorXs forces(num_particles * 2);
    VectorXs dx(num_particles * 2);
    VectorXs dv(num_particles * 2);
    for (int i = 0; i < num_particles * 2; i++){
      forces(i) = 0.0;
      dx(i) = 0.0;
      dv(i) = 0.0;
    }
    scene.accumulateGradU(forces, dx, dv);//, const VectorXs& dx, const VectorXs& dv )

    for (int i = 0; i < num_particles; i++){
      if (!scene.isFixed(i)){
        int index = 2 * i; // even indeces of vector are x params and odd are y params

        const Vector2s next_velocity(v(index) + dt*forces(index)/m(index),
                                     v(index+1) + dt*forces(index+1)/m(index));
        scene.setVelocity(i, next_velocity);
        
        const Vector2s next_position(x(index) + dt*v(index),
                                     x(index + 1) + dt*v(index+1));
        scene.setPosition(i, next_position);

        scalar kinetic_energy = 0;
        text_file << step_count*dt << "\t" << scene.computeKineticEnergy() << endl;
      }
    }

    step_count++;
    return true;
}
开发者ID:TurdOnTheRun,项目名称:animation,代码行数:38,代码来源:ExplicitEuler.cpp


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