Scene Graph

1、Schematic diagram of the scene graph

Peridyno manages all elements including Field, Module and Field in a unified manner through Scene Graph。The following figure shows a scene graph with four simulation nodes:

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2、How to create a scene graph

Next, take fluid simulation as an example to show how to use peridyno to create a complete demo. The complete process consists of the following four steps:

  • Create a scene graph

    std::shared_ptr<SceneGraph> scn = std::make_shared<SceneGraph>();

  • Add a simulation node

    //Add a fluid simulation node
auto fluid = scn->addNode(std::make_shared<ParticleFluid<DataType3f>>());
fluid->loadParticles(Vec3f(0.5, 0.2, 0.4), Vec3f(0.7, 1.5, 0.6), 0.005);
  
//add boundary constraint Node
auto boundary = scn->addNode(std::make_shared<StaticBoundary<DataType3f>>());
boundary->loadSDF(getAssetPath() + "bowl/bowl.sdf", false);
  
//Add particle visualization node
auto visualizer = scn->addNode(std::make_shared<GLPointVisualNode<DataType3f>>());

  • Set the node data connection relationship

    //Fluid Node --> Boundary Constraint Node
fluid->connect(boundary->importParticleSystems());
  
//Fluid Node --> Visualization Node
fluid->connect(visualizer->importParticleSystem());

  • Create an application interface. PeriDyno currently supports both GLFW and QT application interfaces. Taking GLFW as an example, the algorithm flow is as follows:

    GlfwApp window;
  
//Set up the simulation scene
window.setSceneGraph(scn);
  
//Create application interface
window.createWindow(1024, 768);
window.mainLoop();

    The current version requires that the createWindow() function boundary must be made after the setSceneGraph() and setRenderEngine() function calls. If the rendering engine is not explicitly set, the built-in OpenGL-based GLRenderEngine is used by default.

    The effect diagram is as follows：

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Similarly, if using the app interface：

QtApp window;

//Set up the simulation scene
window.setSceneGraph(scn);

//Create application interface
window.createWindow(1024, 768);
window.mainLoop();

对应的效果图下，做的节点编辑器展示了所有的功能节点以及节点之间的链接 关系，通过连接/断开对应的连线可以改变仿真场景图的节点执行顺序。

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完整示例代码参见examples/GL_ParticleFluid和examples/Qt_GLVisualModule。