vtk.js 14版本 加载obj模型并显示模型贴图

以下是加载OBJ模型并显示模型贴图的示例代码：

import 'vtk.js/Rendering/OpenGL';
import 'vtk.js/Rendering/OpenGL2';
import 'vtk.js/Rendering/Core';
import 'vtk.js/Filters/General';
import 'vtk.js/Filters/Sources';
import 'vtk.js/IO/Misc';
import 'vtk.js/Common/Core';
import 'vtk.js/Common/DataModel';
import 'vtk.js/Common/Math';

import vtkActor from 'vtk.js/Rendering/Core/Actor';
import vtkCamera from 'vtk.js/Rendering/Core/Camera';
import vtkColorTransferFunction from 'vtk.js/Rendering/Core/ColorTransferFunction';
import vtkFullScreenRenderWindow from 'vtk.js/Rendering/Misc/FullScreenRenderWindow';
import vtkMapper from 'vtk.js/Rendering/Core/Mapper';
import vtkOBJReader from 'vtk.js/IO/Misc/OBJReader';
import vtkPlaneSource from 'vtk.js/Filters/Sources/PlaneSource';
import vtkRenderer from 'vtk.js/Rendering/Core/Renderer';
import vtkTexture from 'vtk.js/Rendering/Core/Texture';

// Create the renderer and render window
const fullScreenRenderer = vtkFullScreenRenderWindow.newInstance();

const renderer = fullScreenRenderer.getRenderer();
renderer.setBackground(0.2, 0.2, 0.2);

const renderWindow = fullScreenRenderer.getRenderWindow();
renderWindow.setContainer(document.getElementById('vtk-container'));

// Add a plane to the scene for the texture to be applied to
const planeSource = vtkPlaneSource.newInstance();
const planeMapper = vtkMapper.newInstance();
const planeActor = vtkActor.newInstance();

planeSource.setOrigin(-10, -10, 0);
planeSource.setPoint1(10, -10, 0);
planeSource.setPoint2(-10, 10, 0);

planeMapper.setInputConnection(planeSource.getOutputPort());
planeActor.setMapper(planeMapper);
renderer.addActor(planeActor);

// Load the OBJ model
const objReader = vtkOBJReader.newInstance();
objReader.setUrl('model.obj').then(() => {
  const objMapper = vtkMapper.newInstance();
  const objActor = vtkActor.newInstance();

  objMapper.setInputConnection(objReader.getOutputPort());
  objActor.setMapper(objMapper);

  // Apply the texture to the model
  const texture = vtkTexture.newInstance();
  texture.setInterpolate(true);
  texture.setRepeat(false);
  texture.setEdgeClamp(true);
  texture.setInputConnection(objReader.getOutputPort(), 1);
  objActor.addTexture(texture);

  renderer.addActor(objActor);

  // Update the camera position to view the entire scene
  const bounds = objActor.getMapper().getBounds();
  const center = objActor.getCenter();

  const distance = vtkMath.distance(bounds[0], bounds[1], bounds[2], bounds[3], bounds[4], bounds[5]);
  const angle = Math.atan2(distance, vtkMath.distance(...center)) * 2;

  const camera = renderer.getActiveCamera();
  camera.setPosition(center[0], center[1] - distance, center[2]);
  camera.setFocalPoint(...center);
  camera.setViewUp(0, 0, 1);
  camera.setDistance(distance);
  camera.setClippingRange(distance / 10, distance * 10);
  camera.setViewAngle(vtkMath.degreesFromRadians(angle));
  renderer.resetCameraClippingRange();
});

// Create a color transfer function for the plane
const planeColorTransferFunction = vtkColorTransferFunction.newInstance();
planeColorTransferFunction.addRGBPoint(0, 1, 1, 1);
planeColorTransferFunction.addRGBPoint(1, 0, 0, 0);

// Apply the color transfer function to the plane
planeMapper.setLookupTable(planeColorTransferFunction);
planeMapper.setScalarRange(0, 1);

renderWindow.render();

在这个示例中，我们首先创建了一个全屏渲染窗口，并将其渲染器的背景设置为灰色。然后，我们添加了一个平面几何体，并创建了一个颜色传输函数来将其渲染为黑白相间的条纹纹理。

接下来，我们使用OBJReader来加载OBJ模型文件，并创建一个Actor和Mapper来显示模型。我们还创建了一个纹理对象，并将其应用于Actor以显示模型的贴图。

最后，我们更新了相机的位置和方向，以便在屏幕上完整地显示场景，并调用renderWindow.render()方法来渲染场景。