cesium中rectangle是水平垂直于正北方向的,rectangle的属性中有rotation,但是rotation是以矩形的中心点进行旋转的,旋转过程中矩形的形状可能会变形,如果需要以矩形的顶点为原点进行旋转,可以采用primitive的方式添加polygon,并设置polygon的矩阵。
用entity的方式参考cesium 指定点旋转rectangle entity方式 坐标篇-CSDN博客
一、primitive的方式添加polygon
let p1 = [113.389, 38.094669];let p2 = [113.390968, 38.095338];// 通过矩形的2个点,得到多边形的四个点let polygonInstance = new Cesium.GeometryInstance({geometry: Cesium.PolygonGeometry.fromPositions({positions: Cesium.Cartesian3.fromDegreesArray([...p1,p2[0], p1[1],...p2,p1[0], p2[1]]),height: 0,vertexFormat: Cesium.EllipsoidSurfaceAppearance.VERTEX_FORMAT}),attributes: {color: Cesium.ColorGeometryInstanceAttribute.fromColor(Cesium.Color.fromCssColorString('#00ff00').withAlpha(0.5))}});let polygonPrimitive = new Cesium.Primitive({geometryInstances: [polygonInstance],undisplayable: true,appearance: new Cesium.PerInstanceColorAppearance({flat: true,translucent: false})});viewer.scene.primitives.add(polygonPrimitive);
二、设置polygon的矩阵,以p1为原点顺时针旋转30度
let center = Cesium.Cartesian3.fromDegrees(...p1);let localToWorld_Matrix = Cesium.Transforms.eastNorthUpToFixedFrame(center);let worldToLocal_Matrix = Cesium.Matrix4.inverse(localToWorld_Matrix, new Cesium.Matrix4);let rotationZ = Cesium.Matrix3.fromRotationZ(Cesium.Math.toRadians(r));let rotationMatrix = Cesium.Matrix4.fromRotation(rotationZ);let localRotationMatrix = Cesium.Matrix4.multiply(rotationMatrix, worldToLocal_Matrix, new Cesium.Matrix4);let worldMatrix = Cesium.Matrix4.multiply(localToWorld_Matrix, localRotationMatrix, new Cesium.Matrix4);polygonPrimitive.modelMatrix = worldMatrix;
代码解析:Cesium.Matrix3.fromRotationZ(Cesium.Math.toRadians(-30));
- cesium中z轴是向上的,所以面对着屏幕以p1为原点旋转需要调用用fromRotationZcesium mapboxgl+threebox glb 朝向问题 坐标轴方向_threebox z轴向上-CSDN博客
- fromRotationZ()指向正方向为逆时针方向,所以以p1为原点顺时针旋转30度的时候传入角度是-30