开源3D游戏引擎Irrlicht简介

Irrlicht简介

Irrlicht在国内也被叫做“鬼火”引擎，是一款用C++编写的开放源代码的高性能游戏引擎。而且是跨平台的，具有很好的移植性，Irrlicht支持OpenGl、Direcx3D渲染，引擎本身也实现了一套自己的渲染系统。在商业引擎中能够找到的艺术特性，Irrlicht基本都支持。目前有很多项目中都使用到它，Irrlicht社区也比较活跃，可以在互联网上找到不少Irrlicht增强工具，例如irrEdit、irrKlang等。在众多开源游戏引擎中，Irrlicht也是比较受笔者青睐的一款。

Irrlicht官方网站：http://irrlicht.sourceforge.net/

Irrlicht下载与使用

Irrlicht目前最新稳定版本为1.8.1，项目发布在sourceforge平台上，用户可以通过sourceforge网站首页面搜索功能找到Irrlicht项目下载地址，或者从Irrlicht官网获取下载链接。

下载地址：http://irrlicht.sourceforge.net/downloads/

1.目录结构

解压后目录结构如下：

bin：不同平台编译Irrlicht生成的可执行文件和动态库文件放在该目录中。
doc : 该目录中为Irrlicht API文档。
examples ： Irrlicht官方提供的案例程序存放在该目录中。
include ：存放引擎所有头文件。
lib : 该目录存放Irrlicht引擎编译过后生成的静态库。
media ：官方案例所需资源文件存放在此目录中。
source ：存放引擎源码。
tools : 该目录下为Irrlicht引擎相关工具。如irrEdit、GUIEditor等。

2.官方案例

Irrlicht使用起来是非常方便的，这也是笔者比较喜欢它的原因之一。为了方便用户学习和使用引擎，Irrlicht官方提供了大量的例子程序，而且都比较具有代表性。

打开examples目录，Irrlicht已经为目前主流开发工具Windows平台下Visual Studio、MacOS下的Xcode以及Linux平台下的GNU MAKE做好了项目配置。

笔者是在Windows操作系统下使用VS2012进行演示，双击BuildAllExamples_vc11.sln打开解决方案，无需做任何配置即可编译运行程序。

编译运行Collision案例程序：

看起来效果是不是很炫呢?Irrlicht为我们做了大量的封装，即便看似如此复杂的程序，实际代码不超过200行。

#include <irrlicht.h>
#include "driverChoice.h"using namespace irr;#ifdef _MSC_VER
#pragma comment(lib, "Irrlicht.lib")
#endif
enum
{   ID_IsNotPickable = 0,IDFlag_IsPickable = 1 << 0,IDFlag_IsHighlightable = 1 << 1
};
int main()
{video::E_DRIVER_TYPE driverType=video::EDT_OPENGL;//driverChoiceConsole();if (driverType==video::EDT_COUNT)return 1;IrrlichtDevice *device =createDevice(driverType, core::dimension2d<u32>(1024, 768), 16, false);if (device == 0)return 1; // could not create selected driver.video::IVideoDriver* driver = device->getVideoDriver();scene::ISceneManager* smgr = device->getSceneManager();device->getFileSystem()->addFileArchive("../../media/map-20kdm2.pk3");scene::IAnimatedMesh* q3levelmesh = smgr->getMesh("20kdm2.bsp");scene::IMeshSceneNode* q3node = 0;if (q3levelmesh)q3node = smgr->addOctreeSceneNode(q3levelmesh->getMesh(0), 0, IDFlag_IsPickable);scene::ITriangleSelector* selector = 0;if (q3node){q3node->setPosition(core::vector3df(-1350,-130,-1400));selector = smgr->createOctreeTriangleSelector(q3node->getMesh(), q3node, 128);q3node->setTriangleSelector(selector);}scene::ICameraSceneNode* camera =smgr->addCameraSceneNodeFPS(0, 100.0f, .3f, ID_IsNotPickable, 0, 0, true, 3.f);camera->setPosition(core::vector3df(50,50,-60));camera->setTarget(core::vector3df(-70,30,-60));if (selector){scene::ISceneNodeAnimator* anim = smgr->createCollisionResponseAnimator(selector, camera, core::vector3df(30,50,30),core::vector3df(0,-10,0), core::vector3df(0,30,0));selector->drop(); // As soon as we're done with the selector, drop it.camera->addAnimator(anim);anim->drop();  }device->getCursorControl()->setVisible(false);scene::IBillboardSceneNode * bill = smgr->addBillboardSceneNode();bill->setMaterialType(video::EMT_TRANSPARENT_ADD_COLOR );bill->setMaterialTexture(0, driver->getTexture("../../media/particle.bmp"));bill->setMaterialFlag(video::EMF_LIGHTING, false);bill->setMaterialFlag(video::EMF_ZBUFFER, false);bill->setSize(core::dimension2d<f32>(20.0f, 20.0f));bill->setID(ID_IsNotPickable); // This ensures that we don't accidentally ray-pick itscene::IAnimatedMeshSceneNode* node = 0;video::SMaterial material;node = smgr->addAnimatedMeshSceneNode(smgr->getMesh("../../media/faerie.md2"),0, IDFlag_IsPickable | IDFlag_IsHighlightable);node->setPosition(core::vector3df(-90,-15,-140)); // Put its feet on the floor.node->setScale(core::vector3df(1.6f)); // Make it appear realistically scalednode->setMD2Animation(scene::EMAT_POINT);node->setAnimationSpeed(20.f);material.setTexture(0, driver->getTexture("../../media/faerie2.bmp"));material.Lighting = true;material.NormalizeNormals = true;node->getMaterial(0) = material;selector = smgr->createTriangleSelector(node);node->setTriangleSelector(selector);selector->drop(); // We're done with this selector, so drop it now.node = smgr->addAnimatedMeshSceneNode(smgr->getMesh("../../media/ninja.b3d"),0, IDFlag_IsPickable | IDFlag_IsHighlightable);node->setScale(core::vector3df(10));node->setPosition(core::vector3df(-75,-66,-80));node->setRotation(core::vector3df(0,90,0));node->setAnimationSpeed(8.f);node->getMaterial(0).NormalizeNormals = true;node->getMaterial(0).Lighting = true;selector = smgr->createTriangleSelector(node);node->setTriangleSelector(selector);selector->drop();node = smgr->addAnimatedMeshSceneNode(smgr->getMesh("../../media/dwarf.x"),0, IDFlag_IsPickable | IDFlag_IsHighlightable);node->setPosition(core::vector3df(-70,-66,-30)); // Put its feet on the floor.node->setRotation(core::vector3df(0,-90,0)); // And turn it towards the camera.node->setAnimationSpeed(20.f);node->getMaterial(0).Lighting = true;selector = smgr->createTriangleSelector(node);node->setTriangleSelector(selector);selector->drop();node = smgr->addAnimatedMeshSceneNode(smgr->getMesh("../../media/yodan.mdl"),0, IDFlag_IsPickable | IDFlag_IsHighlightable);node->setPosition(core::vector3df(-90,-25,20));node->setScale(core::vector3df(0.8f));node->getMaterial(0).Lighting = true;node->setAnimationSpeed(20.f);// Just do the same as we did above.selector = smgr->createTriangleSelector(node);node->setTriangleSelector(selector);selector->drop();material.setTexture(0, 0);material.Lighting = false;scene::ILightSceneNode * light = smgr->addLightSceneNode(0, core::vector3df(-60,100,400),video::SColorf(1.0f,1.0f,1.0f,1.0f), 600.0f);light->setID(ID_IsNotPickable); // Make it an invalid target for selection.scene::ISceneNode* highlightedSceneNode = 0;scene::ISceneCollisionManager* collMan = smgr->getSceneCollisionManager();int lastFPS = -1;material.Wireframe=true;while(device->run())if (device->isWindowActive()){driver->beginScene(true, true, 0);smgr->drawAll();if (highlightedSceneNode){highlightedSceneNode->setMaterialFlag(video::EMF_LIGHTING, true);highlightedSceneNode = 0;}core::line3d<f32> ray;ray.start = camera->getPosition();ray.end = ray.start + (camera->getTarget() - ray.start).normalize() * 1000.0f;core::vector3df intersection;core::triangle3df hitTriangle;scene::ISceneNode * selectedSceneNode =collMan->getSceneNodeAndCollisionPointFromRay(ray,intersection, hitTriangle, IDFlag_IsPickable, 0);     if(selectedSceneNode){bill->setPosition(intersection);driver->setTransform(video::ETS_WORLD, core::matrix4());driver->setMaterial(material);driver->draw3DTriangle(hitTriangle, video::SColor(0,255,0,0));if((selectedSceneNode->getID() & IDFlag_IsHighlightable) == IDFlag_IsHighlightable){highlightedSceneNode = selectedSceneNode;highlightedSceneNode->setMaterialFlag(video::EMF_LIGHTING, false);}}driver->endScene();int fps = driver->getFPS();if (lastFPS != fps){core::stringw str = L"Collision detection example - Irrlicht Engine [";str += driver->getName();str += "] FPS:";str += fps;device->setWindowCaption(str.c_str());lastFPS = fps;}}device->drop();return 0;
}