Ogre2.1 分析筆記(八) 實現天空盒
1. 新建一個空工程新增如下程式碼，完成Ogre的初始化。
int WinMain(HINSTANCE hInst, HINSTANCE hPrevInstance, LPSTR strCmdLine, INT nCmdShow) {
Ogre::Root *root = new Ogre::Root;
string renderSystemName = "OpenGL 3+ Rendering Subsystem";
//在Root的建構函式中會直接啟動OGL3+和DX11兩種渲染系統，一下程式碼只是去獲取渲染系統的指標
Ogre::RenderSystem *renderSystem =root->getRenderSystemByName(renderSystemName);
renderSystem->setConfigOption("Full Screen", "No");
renderSystem->setConfigOption("Video Mode", "800x600 @32-bit colour");
root->setRenderSystem(renderSystem);
Ogre::RenderWindow *renderWindow = root->initialise(true);
while (true) {
root->renderOneFrame();
}
}
2. 建立相機
Ogre::SceneManager
Ogre::Camera *camera =sceneManager->createCamera("MainCamera", true, true);
camera->setPosition(0,5, 15);
camera->setNearClipDistance(0.2f);
camera->setFarClipDistance(1000.0f);
camera->setAutoAspectRatio(true);
3. 定義合成器。在SkyBox.compositor中新增以下定義。
compositor_node SkyBoxNode
{
in 0 renderWindow
target renderWindow
{
pass clear
{
colour_value0.5 1 1 1
}
passrender_quad
{
quad_normals camera_direction
materialSkyBox
}
}
}
workspace SkyBox
{
connect_outputSkyBoxNode 0
}
4. 新增材質檔案。在SkyBox.material中新增以下程式碼
vertex_program SkyBox_vs glsl
{
sourceSkyBox_vs.glsl
default_params
{
param_named_autoworldViewProj worldviewproj_matrix
}
}
fragment_program SkyBox_ps glsl
{
sourceSkyBox_ps.glsl
default_params
{
param_namedskyCubemap int 0
}
}
material SkyBox
{
technique
{
pass
{
vertex_program_refSkyBox_vs
{
}
fragment_program_refSkyBox_ps
{
}
texture_unit
{
textureSaintPetersBasilica.dds cubic gamma
filtering trilinear
tex_address_mode clamp
}
}
}
}
5. 新增對應的頂點shader和畫素shader。在SkyBox_vs.glsl中新增以下程式碼。
#version 330
in vec4 vertex;
in vec3 normal;
uniform mat4 worldViewProj;
out gl_PerVertex
{
vec4 gl_Position;
};
out block
{
vec3 cameraDir;
} outVs;
void main()
{
gl_Position = (worldViewProj * vertex).xyww;
outVs.cameraDir.xyz = normal.xyz;
}
在在SkyBox_ps.glsl中新增以下程式碼。
#version 330
uniform samplerCube skyCubemap;
in block
{
vec3 cameraDir;
} inPs;
out vec3 fragColour;
void main()
{
//Cubemapsare left-handed
fragColour= texture( skyCubemap, vec3( inPs.cameraDir.xy, -inPs.cameraDir.z ) ).xyz;
}
6. 在程式中新增資源
Ogre::ResourceGroupManager::getSingleton().addResourceLocation("C:/Users/aa/Documents/Visual Studio2015/Projects/ORGE/OgreSkyBox", "FileSystem");
Ogre::ResourceGroupManager::getSingleton().addResourceLocation("C:/Users/aa/Documents/ogre/Samples/Media/materials/textures/Cubemaps", "FileSystem");
Ogre::ResourceGroupManager::getSingleton().initialiseAllResourceGroups();
7. 在程式中新增工作空間
Ogre::CompositorManager2 *compositorManager = root->getCompositorManager2();
compositorManager->addWorkspace(sceneManager,renderWindow, camera, "SkyBox", true);
8. 渲染迴圈
while (true) {
root->renderOneFrame();
}