我正在尝试检测盒形碰撞对象的鼠标尖刺,但是Bullet的rayTest以某种方式显示出奇怪的行为。

这是我的世界设置:

public void create () {
    Bullet.init();
    Gdx.app.log("Bullet", "Version = " + LinearMath.btGetVersion());

    // camera:
    camera = new OrthographicCamera(VIEWPORT_WIDTH, VIEWPORT_HEIGHT);
    camera.position.set(VIEWPORT_WIDTH/2, VIEWPORT_HEIGHT/2, 10f);

    camera.up.set(0f, 1f, 0f);
    camera.lookAt(VIEWPORT_WIDTH/2, VIEWPORT_HEIGHT/2, 0);
    camera.near = 1f;
    camera.far = +100f;
    camera.update();

    closestRayResultCallback = new ClosestRayResultCallback(Vector3.Zero, Vector3.Z);
    btDefaultCollisionConfiguration collisionConfig = new btDefaultCollisionConfiguration();
    btCollisionDispatcher dispatcher = new btCollisionDispatcher(collisionConfig);
    btDbvtBroadphase broadphase = new btDbvtBroadphase();
    collisionWorld = new btCollisionWorld(dispatcher, broadphase, collisionConfig);

    btCollisionShape shape = new btBoxShape(new Vector3(0.50f, 0.50f, 0.50f));
    btCollisionObject obj = new btCollisionObject();
    obj.setCollisionShape(shape);
    collisionWorld.addCollisionObject(obj);

    Matrix4 transform = new Matrix4();
    transform.setTranslation(0.90f, 0.90f, 0f);
    obj.setWorldTransform(transform);

    // Debug:
    debugDrawer = new DebugDrawer();
    collisionWorld.setDebugDrawer(debugDrawer);
    debugDrawer.setDebugMode(btIDebugDraw.DebugDrawModes.DBG_MAX_DEBUG_DRAW_MODE);
}


该设置(我认为)没有什么异常-例外是,也许我使用了正交摄影机。

射线测试代码没有什么特别的,或者:

private btCollisionObject rayTest(int x, int y) {
    Ray ray = camera.getPickRay(x, y);
    rayFrom.set(ray.origin);
    rayTo.set(ray.direction.scl(50)).add(ray.origin);

    Gdx.app.log("Bullet", "rayTest - rayFrom: " + rayFrom + ", rayTo: " + rayTo);

    // we reuse the ClosestRayResultCallback, thus we need to reset its values:
    closestRayResultCallback.setCollisionObject(null);
    closestRayResultCallback.setClosestHitFraction(1f);
    closestRayResultCallback.setRayFromWorld(rayFrom);
    closestRayResultCallback.setRayToWorld(rayTo);

    collisionWorld.rayTest(rayFrom, rayTo, closestRayResultCallback);

    if (closestRayResultCallback.hasHit()) {
        Gdx.app.log("Bullet", "rayTest - has hit");
        return closestRayResultCallback.getCollisionObject();
    }

    return null;

}


在我的渲染循环中,我1)监听鼠标点击,并在单击时调用带有相应鼠标坐标的rayTest方法,然后2)使用调试抽屉渲染碰撞体的盒形。

现在,我的观察是:

该框将按预期方式绘制在应用程序窗口的左下角附近。但是hitTest仅在框的左下角检测到鼠标单击框形状。
更准确地说,仅当鼠标位于框的左下角(此处为(41,41))和(49,49)之间时,才检测到该框中的鼠标单击。框的另一部分中的鼠标单击保持未被检测到。

我在这里想念什么吗?

最佳答案

显然,rayTest有一个错误(Bullet v2.82)。

至少http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=10187&p=34250&hilit=rayTest#p34250http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=10205&p=34323&hilit=rayTest#p34323报告相同的观察结果。这些帖子中提到的两种变通方法(使用btCollisionWorld.updateAAbbs()或使用btDiscreteDynamicsWorld + btRigidBody + StepSimulation)都对我有效。

10-05 17:47