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Learning vtkjs之ImageStreamline

news 来源：原创 2025/5/1 13:15:07

过滤器流线

介绍

vtkImageStreamline - 在 vtkImageData 中积分流线

vtkImageStreamline 是一个过滤器，它从定义了向量场的 vtkImageData 输入中生成流线。此过滤器将在输入中查找向量（即 getVectors()）。然后，它将使用龙格-库塔 2 法从第二个输入的点定义的起始种子集开始积分这些向量，直到达到指定的最大步数或流线离开域。

输出将是一个包含每条流线的折线的 vtkPolyData。目前，此过滤器不将任何输入场插值到流线的点。

效果

在这里插入图片描述

核心代码

数据生成

const vecSource = macro.newInstance((publicAPI, model) => {macro.obj(publicAPI, model); // make it an objectmacro.algo(publicAPI, model, 0, 1); // mixin algorithm code 1 in, 1 outpublicAPI.requestData = (inData, outData) => {// implement requestDataif (!outData[0]) {const id = vtkImageData.newInstance();id.setSpacing(0.1, 0.1, 0.1);const count = 10;id.setExtent(0, count - 1, 0, count - 1, 0, count - 1);const dims = [count, count, count];const newArray = new Float32Array(3 * dims[0] * dims[1] * dims[2]);let i = 0;for (let z = 0; z < count; z++) {for (let y = 0; y < count; y++) {for (let x = 0; x < count; x++) {newArray[i++] = Math.random() * x;const v = 0.1 * y;newArray[i++] = Math.random() * v;newArray[i++] = 0;}}}const da = vtkDataArray.newInstance({numberOfComponents: 3,values: newArray,});da.setName("vectors");const cpd = id.getPointData();cpd.setVectors(da);// Update outputoutData[0] = id;}};
})();

流线提取

 const fullScreenRenderer = vtkFullScreenRenderWindow.newInstance({background: [0, 0, 0],rootContainer: vtkContainerRef.current,});const renderer = fullScreenRenderer.getRenderer();const renderWindow = fullScreenRenderer.getRenderWindow();const planeSource = vtkPlaneSource.newInstance();// planeSource.setOrigin(0.05, 0.05, 0.05);// planeSource.setPoint1(0.05, 0.85, 0.05);// planeSource.setPoint2(0.05, 0.05, 0.85);planeSource.setOrigin(0.01, 0.0, 0.0);planeSource.setPoint1(0.01, 0.9, 0.0);planeSource.setPoint2(0.01, 0.0, 0.9);const sline = vtkImageStreamline.newInstance();sline.setIntegrationStep(0.01);sline.setInputConnection(vecSource.getOutputPort());sline.setInputConnection(planeSource.getOutputPort(), 1);const outlineFilter = vtkOutlineFilter.newInstance();outlineFilter.setInputConnection(vecSource.getOutputPort());context.current = {planeSource,renderer,renderWindow,};addRepresentation(sline, {diffuseColor: [0, 1, 1],lineWidth: 3,});addRepresentation(outlineFilter, {diffuseColor: [1, 0, 0],lineWidth: 1.5,});addRepresentation(planeSource, {representation: Representation.POINTS,pointSize: 10,});renderer.resetCamera();renderWindow.render();