完成下列功能:

1.板件显示
2.板件选中状态
3.标注显示
4.相机控制.

src/PlaneExt.ts

@@ -0,0 +1,46 @@
+import * as THREE from 'three';
+import { Vector3, Line3 } from "three";
+
+export class PlaneExt extends THREE.Plane
+{
+    constructor(normal?: THREE.Vector3, constant?: number)
+    {
+        super(normal, constant);
+    }
+    intersectLine(line: Line3, optionalTarget?: Vector3, extendLine?: boolean): Vector3
+    {
+        let v1 = new Vector3();
+
+        let result = optionalTarget || new Vector3();
+
+        let direction = line.delta(v1);
+
+        let denominator = this.normal.dot(direction);
+
+        if (denominator === 0)
+        {
+            // line is coplanar, return origin
+            if (this.distanceToPoint(line.start) === 0)
+            {
+                return result.copy(line.start);
+            }
+            // Unsure if this is the correct method to handle this case.
+            return undefined;
+        }
+
+        let t = - (line.start.dot(this.normal) + this.constant) / denominator;
+        //If you not extendLine,check intersect point in Line
+        if (!extendLine && (t < 0 || t > 1))
+        {
+            return undefined;
+        }
+
+        return result.copy(direction).multiplyScalar(t).add(line.start);
+    }
+    intersectRay(ray: THREE.Ray, optionalTarget?: Vector3, extendLine?: boolean): Vector3
+    {
+        // 从射线初始位置
+        let line = new THREE.Line3(ray.origin.clone(), ray.origin.clone().add(ray.direction));
+        return this.intersectLine(line, optionalTarget, extendLine);
+    }
+}