如何使用来自Ammo.js的setUserPointer/getUserPointer

Question

我要打印碰撞物体的名字。我举了一个很简单的例子。

我创建了一个对象来保存用户数据：

        const userData = { name: name };

我使用setUserPointer将这个对象保存在一个主体中：

body.setUserPointer(userData);

我尝试使用getUserPointer获取这个名称并打印它们。但我得到的是“未定义”而不是名字：

function detectCollison(): void
{
    const dispatcher = physicsWorld.getDispatcher();
    const numManifolds = dispatcher.getNumManifolds();

    for (let i = 0; i < numManifolds; i++)
    {
        const contactManifold = dispatcher.getManifoldByIndexInternal(i);
        const body0 = contactManifold.getBody0();
        const body1 = contactManifold.getBody1();

        const p0 = body0.getUserPointer();
        const p1 = body1.getUserPointer();

        console.log("first object: " + p0.name);
        console.log("second object: " + p1.name);
    }
}

编辑的

这是纯TypeScript版本。我试图将名字保留为身体属性，但它也不起作用。它打印“未定义”而不是名称：

        (this.body as any).name = name;

        physicsWorld.addRigidBody(this.body);

function detectCollison(): void
{
    const dispatcher = physicsWorld.getDispatcher();
    const numManifolds = dispatcher.getNumManifolds();

    for (let i = 0; i < numManifolds; i++)
    {
        const contactManifold = dispatcher.getManifoldByIndexInternal(i);
        const body0 = contactManifold.getBody0();
        const body1 = contactManifold.getBody1();

        console.log("first object: " + (body0 as any).name);
        console.log("second object: " + (body1 as any).name);
    }
}

Answer 1

解决方案：

const userData = { name: name };
(this.body as any).userData = userData;

function detectCollison(): void
{
    const dispatcher = physicsWorld.getDispatcher();
    const numManifolds = dispatcher.getNumManifolds();

    for (let i = 0; i < numManifolds; i++)
    {
        const contactManifold = dispatcher.getManifoldByIndexInternal(i);
        const body0 = contactManifold.getBody0();
        const body1 = contactManifold.getBody1();

        const rb0 = (Ammo as any).castObject( contactManifold.getBody0(), Ammo.btRigidBody );
        const rb1 = (Ammo as any).castObject( contactManifold.getBody1(), Ammo.btRigidBody );

        console.log("first object:", rb0.userData);
        console.log("second object:", rb1.userData);
    }
}