Rays and Collisions

[primesoftware]

Hello all! I am new around here, but not new to game dev. I was using the Godot engine for a bit, but wasn't happy with it so I switched to Babylon. I need a little help with collisions and ray casting though. I've combed through all the tutorials and can't seem to get this working. I am loading a scene imported from Blender. In Blender I made a simple Box where I want to cast a ray to when clicked on. Simple picking isn't going to work for me because I only want to perform an action when a small area of larger model is clicked. The Box is not visible, but is registered as a physics object. Clicking the invisible box does not work at all. I just end up hitting the visible model underneath the invisible box.

var canvas, engine, scene, camera;document.addEventListener("DOMContentLoaded", function () {    if (BABYLON.Engine.isSupported()) {        initScene();    }}, false);function initScene() {    canvas = document.getElementById("webGLCanvas");    engine = new BABYLON.Engine(canvas, true);        BABYLON.SceneLoader.Load("assets/models/", "Gameboard.babylon", engine, function (gameScene) {        gameScene.executeWhenReady(function () {            gameScene.enablePhysics(new BABYLON.Vector3(0, -10, 0), new BABYLON.OimoJSPlugin());            gameScene.collisionsEnabled = true;                        var light = new BABYLON.PointLight("light", new BABYLON.Vector3(0, 5, -5), gameScene);                        camera = new BABYLON.FreeCamera("camera", new BABYLON.Vector3(0, 4, -10), gameScene);            camera.setTarget(new BABYLON.Vector3(0, 0, 10));            camera.attachControl(canvas);                        var counterHitBox = gameScene.getMeshByName("CounterHitBox");            counterHitBox.checkCollisions = true;            counterHitBox.setPhysicsState(BABYLON.PhysicsEngine.BoxImpostor, {mass: 0, friction: 0.5, restitution: 0.7});                        gameScene.onPointerDown = function (evt) {                var pickResult = gameScene.pick(gameScene.pointerX, gameScene.pointerY);                                alert(pickResult.pickedMesh.name);            };                        engine.runRenderLoop(function() {                gameScene.render();            });        });    }, function (progress) {        // To do: give progress feedback to user    });};

[GameMonetize]

Hello and welcome!

 

Physics and picking are not related as they do not use the same internal engine. The picking just need you to set mesh.isPickable = true

 

Example here:

http://www.babylonjs-playground.com/#UF7SS

[primesoftware]

Hello and welcome!

 

Physics and picking are not related as they do not use the same internal engine. The picking just need you to set mesh.isPickable = true

 

Example here:

http://www.babylonjs-playground.com/#UF7SS

 

Thank you for the welcome! I gave this a try, but it doesn't pick my invisible mesh. The mesh is invisible, but enabled. Does that make a difference? I saw someone else said use the pick function with a predicate. I gave that a try, but it was picking every mesh on the screen even if I didn't click on it.

 

Edit: So I figured it out using this thread (http://www.html5gamedevs.com/topic/7709-scenepick-a-mesh-that-is-enabled-but-not-visible/). The predicate function just says which meshes are valid, not which ones were picked. That was why I was getting an alert with all the meshes in my scene.

 

This code now works:

            gameScene.onPointerDown = function (evt) {                var pickResult = gameScene.pick(gameScene.pointerX, gameScene.pointerY, function(mesh) {                    return mesh.isPickable && mesh.isEnabled();                });                                alert(pickResult.pickedMesh.name);            };