intersect.md

Collision Detection

Authors: Xunyi, youyou

Cocos Creator provides a set of API for detecting 3D object collision, and user can use these APIs for detection such as raycast.

Raycast

• cc.geomUtils.intersect.raycast(rootNode, ray, handler, filter)

// Get a ray from the screen that is directed to the screen based on the point clicked
let ray = camera.getRay(touchPos);
// Detects downward based on the incoming root node and returns the detection results
// The returned result contains the node and distance
let results = cc.geomUtils.intersect.raycast(cc.director.getScene(), ray);
for (let i = 0; i < results.length; i++) {
    results[i].node.opacity = 100;
}

If you want to detect more accurately, you can pass in a handler function to detect.

let handler = function (modelRay, node, distance) {
    // modelRay is the ray that ray convert to the node's local coordinate system
    let meshRenderer = node.getComponent(cc.MeshRenderer);
    if (meshRenderer && meshRenderer.mesh) {
        // If a mesh renderer is present, the mesh is detected. Although it consumes more performance, but the detection is more accurate
        return cc.geomUtils.intersect.rayMesh(modelRay, meshRenderer.mesh);
    }

    // return
    return distance;
};

let results = cc.geomUtils.intersect.raycast(cc.director.getScene(), ray, handler);