线框渲染

1、线框渲染

案例位置：examples/Cuda/Tutorials/GL_Wireframe

功能介绍：该案例展示将模型表面绘制成线框。

案例说明：该案例主要展示如何使用渲染节点，并以GLWireframeVisualModulel节点为例，将仿真物体以线框的形式展示。线条的形式有两种，一种是线段模式，一种是圆柱模式（加粗的线段）。

2、程序实现

接下来介绍案例的实现过程：

  • 创建场景图:
std::shared_ptr<SceneGraph> scn = std::make_shared<SceneGraph>();
  • 常见一些正方体，四面体和球体等刚体模型:
auto rigid = scn->addNode(std::make_shared<RigidBodySystem<DataType3f>>());

	RigidBodyInfo rigidBody;
	rigidBody.linearVelocity = Vec3f(0.5, 0, 0);
	BoxInfo box;
	for (int i = 8; i > 1; i--)
		for (int j = 0; j < i + 1; j++)
		{
			box.center = 0.5f * Vec3f(0.5f, 1.1 - 0.13 * i, 0.12f + 0.21 * j + 0.1 * (8 - i));
			box.halfLength = 0.5f * Vec3f(0.065, 0.065, 0.1);
			rigid->addBox(box, rigidBody);
		}

	SphereInfo sphere;
	sphere.center = Vec3f(0.5f, 0.75f, 0.5f);
	sphere.radius = 0.025f;

	RigidBodyInfo rigidSphere;
	rigid->addSphere(sphere, rigidSphere);

	sphere.center = Vec3f(0.5f, 0.95f, 0.5f);
	sphere.radius = 0.025f;
	rigid->addSphere(sphere, rigidSphere);

	sphere.center = Vec3f(0.5f, 0.65f, 0.5f);
	sphere.radius = 0.05f;
	rigid->addSphere(sphere, rigidSphere);

	TetInfo tet;
	tet.v[0] = Vec3f(0.5f, 1.1f, 0.5f);
	tet.v[1] = Vec3f(0.5f, 1.2f, 0.5f);
	tet.v[2] = Vec3f(0.6f, 1.1f, 0.5f);
	tet.v[3] = Vec3f(0.5f, 1.1f, 0.6f);
	rigid->addTet(tet, rigidSphere);
  • 将单元转化为三角网格，并创建GLWireframeVisualModule渲染节点:
	auto mapper = std::make_shared<DiscreteElementsToTriangleSet<DataType3f>>();
	rigid->stateTopology()->connect(mapper->inDiscreteElements());
	rigid->graphicsPipeline()->pushModule(mapper);

	auto sRender = std::make_shared<GLWireframeVisualModule>();
	sRender->setColor(Vec3f(1, 1, 0));
	sRender->varRenderMode()->getDataPtr()->setCurrentKey(GLWireframeVisualModule::LINE);
	mapper->outTriangleSet()->connect(sRender->inEdgeSet());
	rigid->graphicsPipeline()->pushModule(sRender);