菜鳥學Ogre教程

這裡參照的是OgreWiki初級教程，用的是網上提供的 Ogre Wiki Tutorial Framework。用的cmake編譯執行。
先看最終效果：

核心代碼：
void TutorialApplication::createScene(void)
{
mSceneMgr->setAmbientLight(Ogre::ColourValue(1.0, 1.0, 1.0));
Ogre::Entity* ogreHead = mSceneMgr->createEntity("Head", "ogrehead.mesh");
Ogre::SceneNode* headNode = mSceneMgr->getRootSceneNode()->createChildSceneNode("HeadNode");
headNode->attachObject(ogreHead);
 
headNode->yaw( Ogre::Degree( -90 ) );
 
Ogre::Entity* ogreHead2 = mSceneMgr->createEntity( "Head2", "ogrehead.mesh" );
Ogre::SceneNode* headNode2 = mSceneMgr->getRootSceneNode()->createChildSceneNode( "HeadNode2", Ogre::Vector3( 100, 0, 0 ) );
headNode2->attachObject( ogreHead2 );
 
headNode2->pitch( Ogre::Degree( -90 ) );
headNode2->scale( 1, 2, 1 );
 
Ogre::Entity* ogreHead3 = mSceneMgr->createEntity( "Head3", "ogrehead.mesh" );
Ogre::SceneNode* headNode3 = mSceneMgr->getRootSceneNode()->createChildSceneNode( "HeadNode3", Ogre::Vector3( 200, 0, 0 ) );
headNode3->attachObject( ogreHead3 );
 
headNode3->roll( Ogre::Degree( -90 ) );
}

幾個重要的概念：
1．  SceneManager：所有屏幕上可見的東西都由SceneManager來管理；有多種類型的SceneManager，分別用來渲染Terrain、BSP等等。
2．  Entity：初步的理解一個Entity代表一個Mesh（可以含有動畫），Light，Camera，Particle，Billboard不用Entity表示。Entity不能直接加到場景中，必須先attach到一個SceneNode上，SceneNode管理位置和方向。
3．  SceneNode：SceneNode管理位置和方向；需要注意子節點的是在父節點的空間中；一個SceneNode可以管理多個對象。

4．  OGRE中的Entity和SceneNode都必須指定全局唯一的名稱。

CMakeFiles.txt也需要一些改動:

#/*
#-----------------------------------------------------------------------------
#Filename:    CMakeLists.txt
#-----------------------------------------------------------------------------
#
#This source file is part of the
#   ___                 __    __ _ _    _
#  /___\__ _ _ __ ___  / / /\ \ (_) | _(_)
# //  // _` | '__/ _ \ \ \/  \/ / | |/ / |
#/ \_// (_| | | |  __/  \  /\  /| |   <| |
#\___/ \__, |_|  \___|   \/  \/ |_|_|\_\_|
#      |___/                             
#      Tutorial Framework
#      http://www.ogre3d.org/tikiwiki/
#-----------------------------------------------------------------------------
#*/
cmake_minimum_required(VERSION 2.6)
 
project(OgreApp)
set(CMAKE_MODULE_PATH "/usr/local/lib/OGRE/cmake/;${CMAKE_MODULE_PATH}")
set(OGRE_SAMPLES_INCLUDEPATH "/home/tao/workspace/ogre_src_v1-8-0/Samples/Common/include/")
if (CMAKE_BUILD_TYPE STREQUAL "")
  # CMake defaults to leaving CMAKE_BUILD_TYPE empty. This screws up
  # differentiation between debug and release builds.
  set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING "Choose the type of build, options are: None (CMAKE_CXX_FLAGS or CMAKE_C_FLAGS used) Debug Release RelWithDebInfo MinSizeRel." FORCE)
endif ()
 
set(CMAKE_DEBUG_POSTFIX "_d")
 
set(CMAKE_INSTALL_PREFIX "${CMAKE_CURRENT_BINARY_DIR}/dist")
 
find_package(OGRE REQUIRED)
 
#if(NOT "${OGRE_VERSION_NAME}" STREQUAL "Cthugha")
#  message(SEND_ERROR "You need Ogre 1.7 Cthugha to build this.")
#endif()
 
find_package(OIS REQUIRED)
 
if(NOT OIS_FOUND)
message(SEND_ERROR "Failed to find OIS.")
endif()
 
# Find Boost
if (NOT OGRE_BUILD_PLATFORM_IPHONE)
if (WIN32 OR APPLE)
set(Boost_USE_STATIC_LIBS TRUE)
else ()
# Statically linking boost to a dynamic Ogre build doesn't work on Linux 64bit
set(Boost_USE_STATIC_LIBS ${OGRE_STATIC})
endif ()
if (MINGW)
# this is probably a bug in CMake: the boost find module tries to look for
# boost libraries with name libboost_*, but CMake already prefixes library
# search names with "lib". This is the workaround.
set(CMAKE_FIND_LIBRARY_PREFIXES ${CMAKE_FIND_LIBRARY_PREFIXES} "")
endif ()
set(Boost_ADDITIONAL_VERSIONS "1.44" "1.44.0" "1.42" "1.42.0" "1.41.0" "1.41" "1.40.0" "1.40" "1.39.0" "1.39" "1.38.0" "1.38" "1.37.0" "1.37" )
# Components that need linking (NB does not include header-only components like bind)
set(OGRE_BOOST_COMPONENTS thread date_time)
find_package(Boost COMPONENTS ${OGRE_BOOST_COMPONENTS} QUIET)
if (NOT Boost_FOUND)
# Try again with the other type of libs
set(Boost_USE_STATIC_LIBS NOT ${Boost_USE_STATIC_LIBS})
find_package(Boost COMPONENTS ${OGRE_BOOST_COMPONENTS} QUIET)
endif()
find_package(Boost QUIET)
 
# Set up referencing of Boost
include_directories(${Boost_INCLUDE_DIR})
add_definitions(-DBOOST_ALL_NO_LIB)
set(OGRE_LIBRARIES ${OGRE_LIBRARIES} ${Boost_LIBRARIES})
endif()
 
set(HDRS
./BaseApplication.h
./TutorialApplication.h
)
 
set(SRCS
./BaseApplication.cpp
./TutorialApplication.cpp
)
 
include_directories( ${OIS_INCLUDE_DIRS}
${OGRE_INCLUDE_DIRS}
${OGRE_SAMPLES_INCLUDEPATH}
)
 
add_executable(OgreApp WIN32 ${HDRS} ${SRCS})
 
set_target_properties(OgreApp PROPERTIES DEBUG_POSTFIX _d)
 
target_link_libraries(OgreApp ${OGRE_LIBRARIES} ${OIS_LIBRARIES})
 
file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/dist/bin)
file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/dist/media)

set(EXECUTABLE_OUTPUT_PATH ${PROJECT_BINARY_DIR}/dist/bin)

install(TARGETS OgreApp
RUNTIME DESTINATION bin
CONFIGURATIONS All)
 
install(DIRECTORY ${CMAKE_SOURCE_DIR}/dist/media
DESTINATION ./
CONFIGURATIONS Release RelWithDebInfo Debug
)
 
install(FILES ${CMAKE_SOURCE_DIR}/dist/bin/plugins.cfg
${CMAKE_SOURCE_DIR}/dist/bin/resources.cfg
DESTINATION bin
CONFIGURATIONS Release RelWithDebInfo Debug
)

Ogre相關閱讀：http://www.linuxidc.com/search.aspx?Where=Nkey&Keyword=Ogre