text: 
  
  class LocalSpaceFluid : public Scene
  {
  public:
  
  	LocalSpaceFluid (const char* name) : Scene(name) {}
  
  	void Initialize()
  	{
  		const float radius = 0.05f;
  		const float restDistance = radius*0.6f;
  
  		int dx = int(ceilf(1.f / restDistance));
  		int dy = int(ceilf(1.f / restDistance));
  		int dz = int(ceilf(1.f / restDistance));
  
  		CreateParticleGrid(Vec3(0.0f, 1.0f, 0.0f), dx, dy, dz, restDistance, Vec3(0.0f), 1.0f, false, 0.0f, NvFlexMakePhase(0, eNvFlexPhaseSelfCollide | eNvFlexPhaseFluid), restDistance*0.01f);
  
  		Vec3 lower, upper;
  		GetParticleBounds(lower, upper);
  
  		Vec3 center = (lower+upper)*0.5f;
  
  		Mesh* shape = ImportMesh("../../data/torus.obj");
  		shape->Transform(ScaleMatrix(Vec3(0.7f)));
  		
  		//Mesh* box = ImportMesh("../../data/sphere.ply");
  		//box->Transform(TranslationMatrix(Point3(0.0f, 0.1f, 0.0f))*ScaleMatrix(Vec3(1.5f)));
  
  		// invert box faces
  		for (int i=0; i < int(shape->GetNumFaces()); ++i)
  			swap(shape->m_indices[i*3+0], shape->m_indices[i*3+1]);		
  
  		shape->CalculateNormals();
  
  		// shift into torus interior
  		for (int i=0; i < g_buffers->positions.size(); ++i)
  			(Vec3&)(g_buffers->positions[i]) -= Vec3(2.1f, 0.0f, 0.0f);
  
  		mesh = CreateTriangleMesh(shape);
  		AddTriangleMesh(mesh, Vec3(center), Quat(), 1.0f);
  
  		// initialize our moving frame to the center of the box
  		NvFlexExtMovingFrameInit(&meshFrame, center, Quat());
  
  		g_numSubsteps = 2;
  
  		g_params.radius = radius;
  		g_params.fluidRestDistance = restDistance;
  		g_params.dynamicFriction = 0.f;
  		g_params.restitution = 0.0f;
  		g_params.collisionDistance = 0.05f;
  		g_params.shapeCollisionMargin = 0.00001f;
  		g_params.maxSpeed = g_numSubsteps*restDistance/g_dt;		
  
  		g_params.numIterations = 4;
  
  		g_params.smoothing = 0.4f;
  		g_params.viscosity = 0.001f;
  		g_params.cohesion = 0.05f;
  		g_params.surfaceTension = 0.0f;
  		
  		translation = center;
  		rotation = 0.0f;
  		rotationSpeed = 0.0f;
  
  		linearInertialScale = 0.25f;
  		angularInertialScale = 0.75f;
  
  		// draw options		
  		g_drawPoints = false;
  		g_drawEllipsoids = true;
  		g_drawDiffuse = true;
  	}
  
  	virtual void DoGui()
  	{
  		imguiSlider("Rotation", &rotationSpeed, 0.0f, 7.0f, 0.1f);
  		imguiSlider("Translation", &translation.x, -2.0f, 2.0f, 0.001f);
  		imguiSlider("Linear Inertia", &linearInertialScale, 0.0f, 1.0f, 0.001f);
  		imguiSlider("Angular Inertia", &angularInertialScale, 0.0f, 1.0f, 0.001f);
  	}
  
  	virtual void Update()
  	{
  		rotation += rotationSpeed*g_dt;
  
  		// new position of the box center
  		Vec3 newPosition = translation;//meshFrame.GetPosition() + Vec3(float(g_lastdx), 0.0f, float(g_lastdy))*0.001f;
  		Quat newRotation = QuatFromAxisAngle(Vec3(0.0f, 1.0f, 0.0f), rotation);
  
  		NvFlexExtMovingFrameUpdate(&meshFrame, newPosition, newRotation, g_dt);
  
  		// update all the particles in the sim with inertial forces
  		NvFlexExtMovingFrameApply(
  			&meshFrame, 
  			&g_buffers->positions[0].x, 
  			&g_buffers->velocities[0].x, 
  			g_buffers->positions.size(),
  			linearInertialScale,
  			angularInertialScale,
  			g_dt);
  
  		// update torus transform
  		g_buffers->shapePrevPositions[0] = g_buffers->shapePositions[0];
  		g_buffers->shapePrevRotations[0] = g_buffers->shapeRotations[0];
  
  		g_buffers->shapePositions[0] = Vec4(newPosition, 1.0f);
  		g_buffers->shapeRotations[0] = newRotation;
  
  		UpdateShapes();
  	}
  
  	Vec3 translation;
  	float rotation;
  	float rotationSpeed;
  
  	float linearInertialScale;
  	float angularInertialScale;
  
  	NvFlexExtMovingFrame meshFrame;
  
  	NvFlexTriangleMeshId mesh;
  };