ogre 3d 1.7 beginner’s guide 第四章 第一小节 中文翻译 准备一个场景

4 Getting User Input and Using the Frame Listener

【 第四章 获取用户输入和使用帧监听 】

Until now, we always created scenes which were static and didn't have anything moving in them. We will change this with this chapter.

【 迄今为止，我们总是创建静止的场景并且在场景中没有移动的物体。在这一章，我们将会改变这种现状。 】

In this chapter, we will:

* Learn what a FrameListener is

* Learn how to process user input

* Combine both concepts to create our own camera control

So let's get on with it...

【

在这章，我们将会：

 认识什么是帧监听

 认识如何处理用户输入

 结合两种概念创建我们自己的相机控制

】

Preparing a scene

【 准备一个场景 】

Before adding moving things to our scene, we need a scene to add them to. So let's create a scene.

【 在添加移动物体之前，我们首先应创建一个可添加物体的场景。然后让我们一起创建一个场景吧。 】

Time for action – preparing a scene

【 实践时刻 —— 准备一个场景 】

We will use a slightly different version of the scene from the previous chapter:

【 我们将使用和之前章节中略微不同的创建场景的版本。 】

1. Delete all code in the createScene() and the createCamera() functions.

【 1. 删除createScene() 和createCamera() 函数中的所有代码：】

2. Delete the createViewports() function.

【 2. 删除createViewports()函数。】

3. Add a new member variable to the class. This member variable is a pointer to a

scene node:

【 3. 添加一个新的成员变量到类中。这个成员变量是一个场景结点的指针：】

private:

Ogre::SceneNode* _SinbadNode;

4. Create a plane and add it to the scene using the createScene() method:

【 4. 使用createScene() 函数创建一个平面并添加它到场景之中：】

Ogre::Plane plane(Vector3::UNIT_Y, -10);

Ogre::MeshManager::getSingleton().createPlane("plane",ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME, plane,1500,1500,200,200,true,1,5,5,Vector3::UNIT_Z);

Ogre::Entity* ent = mSceneMgr->createEntity("LightPlaneEntity", "plane");

mSceneMgr->getRootSceneNode()->createChildSceneNode()->attachObject(ent);

ent->setMaterialName("Examples/BeachStones");

5. Then add a light to the scene:

【 5. 然后添加一个光源到场景中：】

Ogre::Light* light = mSceneMgr->createLight("Light1");

light->setType(Ogre::Light::LT_DIRECTIONAL);

light->setDirection(Ogre::Vector3(1,-1,0));

6. We also need an instance of Sinbad; create a node and attach the instance to it:

【 6. 我们也需要一个Sinbad的实例，创建一个结点并关联实例。】

Ogre::SceneNode* node = mSceneMgr->createSceneNode("Node1");

mSceneMgr->getRootSceneNode()->addChild(node);

Ogre::Entity* Sinbad = mSceneMgr->createEntity("Sinbad", "Sinbad.mesh");

_SinbadNode = node->createChildSceneNode("SinbadNode");

_SinbadNode->setScale(3.0f,3.0f,3.0f);

_SinbadNode->setPosition(Ogre::Vector3(0.0f,4.0f,0.0f));

_SinbadNode->attachObject(Sinbad);

7. We also want shadows in this scene; so activate them:

【 7. 我们也想在场景中增加阴影；所以添加它们：】

mSceneMgr->setShadowTechnique(SHADOWTYPE_STENCIL_ADDITIVE);

8. Create a camera and position it at (0,100,200) and let it look at (0,0,0); remember to add the code to the createCamera() function:

【 8. 创建一个摄像机并放置它在(0,100,200) 并把镜头朝向（0,0,0）；记住添加代码到createCamera() 函数中。】

mCamera = mSceneMgr->createCamera("MyCamera1");

mCamera->setPosition(0,100,200);

mCamera->lookAt(0,0,0);

mCamera->setNearClipDistance(5);

9. Compile and run the application, and you should see the following image:

【 编译运行，你将会看到下面图中的效果】

What just happened?

【 刚刚发生了什么？】

We used the knowledge from the previous chapters to create a scene. We should be able

to understand what happened. If not, we should go back to the previous chapters and read

them again until we understand everything.

【 我们使用在之前章节学到的东西创建了一个场景。我们应可以理解发生了什么。如果没有的话，我们就应该回过头再看看之前的章节直到我们可以理解为止。】