✨ fix: update intersection logic

Author: xiangechen

packages/chili-core/src/math/ray.ts

@@ -24,11 +24,13 @@ export class Ray {
         this.direction = n;
     }
 
-    intersect(right: Ray): XYZ | undefined {
-        if (this.direction.isParallelTo(right.direction)) return undefined;
+    intersect(right: Ray, tolerance = 1e-6): XYZ | undefined {
+        if (this.direction.isParallelTo(right.direction, tolerance)) return undefined;
         const result = this.nearestTo(right);
         const vec = result.sub(right.location);
-        return vec.isParallelTo(right.direction) ? result : undefined;
+        if (vec.length() < tolerance) return result;
+
+        return vec.isParallelTo(right.direction, tolerance) ? result : undefined;
     }
 
     distanceTo(right: Ray): number {

packages/chili-core/test/ray.test.ts

@@ -26,9 +26,11 @@ describe("test ray", () => {
     });
 
     test("test intersect", () => {
-        let r1 = new Ray(XYZ.zero, XYZ.unitX);
-        let r2 = new Ray(XYZ.unitX.add(XYZ.unitY), XYZ.unitY);
+        const r1 = new Ray(XYZ.zero, XYZ.unitX);
+        const r11 = new Ray(XYZ.zero, XYZ.unitY);
+        const r2 = new Ray(XYZ.unitX.add(XYZ.unitY), XYZ.unitY);
         expect(r1.intersect(r2)).toStrictEqual(XYZ.unitX);
+        expect(r1.intersect(r11)).toStrictEqual(XYZ.zero);
 
         const r3 = new Ray(XYZ.zero, XYZ.unitX);
         const r4 = new Ray(XYZ.unitY, XYZ.unitX);