LibGDX 0.9.9-在环境中应用立方体贴图

Question

我正在使用LibGDX 0.9.9。我正在尝试渲染立方体贴图和雾。所以我的代码片段如下：

public void show() {
    modelBatch = new ModelBatch();
    environment = new Environment();
    environment.set(new ColorAttribute(ColorAttribute.AmbientLight, 1.0f, 0.4f, 0.4f, 1f));

    environment.set(new ColorAttribute(ColorAttribute.Fog, 0.9f, 1f, 0f, 1f));
    environment.add(new DirectionalLight().set(0.8f, 0.8f, 0.8f, -1f, -0.8f, -0.2f));

    cubemap = new Cubemap(Gdx.files.internal("cubemap/pos-x.png"), 
                Gdx.files.internal("cubemap/neg-x.png"), 
                Gdx.files.internal("cubemap/pos-y.png"), 
                Gdx.files.internal("cubemap/neg-y.png"), 
                Gdx.files.internal("cubemap/pos-z.png"), 
                Gdx.files.internal("cubemap/neg-z.png"));
    environment.set(new CubemapAttribute(CubemapAttribute.EnvironmentMap, cubemap));

    cam = new PerspectiveCamera(67, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
    cam.position.set(1f, 1f, 1f);
    cam.lookAt(0,0,0);
    cam.near = 0.1f;
    cam.far = 300f;
    cam.update();

    ModelLoader loader = new ObjLoader();

    model = loader.loadModel(Gdx.files.internal("earth/earth.obj"));


    instance = new ModelInstance(model);



    NodePart blockPart = model.nodes.get(0).parts.get(0);

    renderable = new Renderable();
    blockPart.setRenderable(renderable);
    renderable.environment = environment;
    renderable.worldTransform.idt();

    renderContext = new RenderContext(new DefaultTextureBinder(DefaultTextureBinder.WEIGHTED, 1));

    shader = new DefaultShader(renderable);
    shader.init();

    camController = new CameraInputController(cam);
    Gdx.input.setInputProcessor(camController);
}

@Override
public void render(float delta) {
camController.update();

    Gdx.gl.glViewport(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
    Gdx.gl.glClearColor(0, 0, 0, 1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT);

    renderContext.begin();
    shader.begin(cam, renderContext);

    shader.render(renderable);
    shader.end();
    renderContext.end();
}

但是什么也没发生。我只看到对象。我究竟做错了什么？

Answer 1

花了一些时间后，我在LibGDX中实现了多维数据集映射。也许，这不是理想的解决方案，但仅此而已（至少我什么也找不到）。因此，我使用了本机OpenGL
ES函数和LibGDX。我的课程如下：

public class EnvironmentCubemap implements Disposable{

protected final Pixmap[] data = new Pixmap[6];  
protected ShaderProgram shader;

protected int u_worldTrans;
protected Mesh quad;
private Matrix4 worldTrans;
private Quaternion q;

protected String vertexShader = " attribute vec3 a_position; \n"+
        " attribute vec3 a_normal; \n"+
        " attribute vec2 a_texCoord0; \n"+          
        " uniform mat4 u_worldTrans; \n"+                   
        " varying vec2 v_texCoord0; \n"+
        " varying vec3 v_cubeMapUV; \n"+            
        " void main() { \n"+
        "     v_texCoord0 = a_texCoord0;     \n"+
        "     vec4 g_position = u_worldTrans * vec4(a_position, 1.0); \n"+
        "     v_cubeMapUV = normalize(g_position.xyz); \n"+
        "     gl_Position = vec4(a_position, 1.0); \n"+
        " } \n";

protected String fragmentShader = "#ifdef GL_ES \n"+
        " precision mediump float; \n"+
        " #endif \n"+           
        " uniform samplerCube u_environmentCubemap; \n"+            
        " varying vec2 v_texCoord0; \n"+
        " varying vec3 v_cubeMapUV; \n"+            
        " void main() {      \n"+
        "   gl_FragColor = vec4(textureCube(u_environmentCubemap, v_cubeMapUV).rgb, 1.0);   \n"+
        " } \n";

public String getDefaultVertexShader(){
    return vertexShader;
}

public String getDefaultFragmentShader(){
    return fragmentShader;
}

public EnvironmentCubemap (Pixmap positiveX, Pixmap negativeX, Pixmap positiveY, Pixmap negativeY, Pixmap positiveZ, Pixmap negativeZ) {
    data[0]=positiveX;
    data[1]=negativeX;

    data[2]=positiveY;
    data[3]=negativeY;

    data[4]=positiveZ;
    data[5]=negativeZ;

    init();   
}

public EnvironmentCubemap (FileHandle positiveX, FileHandle negativeX, FileHandle positiveY, FileHandle negativeY, FileHandle positiveZ, FileHandle negativeZ) {
    this(new Pixmap(positiveX), new Pixmap(negativeX), new Pixmap(positiveY), new Pixmap(negativeY), new Pixmap(positiveZ), new Pixmap(negativeZ));
}

//IF ALL SIX SIDES ARE REPRESENTED IN ONE IMAGE
public EnvironmentCubemap (Pixmap cubemap) {        
    int w = cubemap.getWidth();
    int h = cubemap.getHeight();
    for(int i=0; i<6; i++) data[i] = new Pixmap(w/4, h/3, Format.RGB888);
    for(int x=0; x<w; x++)
        for(int y=0; y<h; y++){
            //-X
            if(x>=0 && x<=w/4 && y>=h/3 && y<=h*2/3) data[1].drawPixel(x, y-h/3, cubemap.getPixel(x, y));
            //+Y
            if(x>=w/4 && x<=w/2 && y>=0 && y<=h/3) data[2].drawPixel(x-w/4, y, cubemap.getPixel(x, y));
            //+Z
            if(x>=w/4 && x<=w/2 && y>=h/3 && y<=h*2/3) data[4].drawPixel(x-w/4, y-h/3, cubemap.getPixel(x, y));
            //-Y
            if(x>=w/4 && x<=w/2 && y>=h*2/3 && y<=h) data[3].drawPixel(x-w/4, y-h*2/3, cubemap.getPixel(x, y));
            //+X
            if(x>=w/2 && x<=w*3/4 && y>=h/3 && y<=h*2/3) data[0].drawPixel(x-w/2, y-h/3, cubemap.getPixel(x, y));
            //-Z
            if(x>=w*3/4 && x<=w && y>=h/3 && y<=h*2/3) data[5].drawPixel(x-w*3/4, y-h/3, cubemap.getPixel(x, y));
        }
    cubemap.dispose();
    cubemap=null;
    init();     
}

private void init(){        
     shader = new ShaderProgram(vertexShader, fragmentShader);
        if (!shader.isCompiled())
            throw new GdxRuntimeException(shader.getLog());

     u_worldTrans = shader.getUniformLocation("u_worldTrans");

     quad = createQuad();      
     worldTrans = new Matrix4();         
     q = new Quaternion();

     initCubemap();
}

private void initCubemap(){
    //bind cubemap
    Gdx.gl20.glBindTexture(GL20.GL_TEXTURE_CUBE_MAP, 0);
    Gdx.gl20.glTexImage2D(GL20.GL_TEXTURE_CUBE_MAP_POSITIVE_X, 0, GL20.GL_RGB, data[0].getWidth(), data[0].getHeight(), 0, GL20.GL_RGB, GL20.GL_UNSIGNED_BYTE, data[0].getPixels());
    Gdx.gl20.glTexImage2D(GL20.GL_TEXTURE_CUBE_MAP_NEGATIVE_X, 0, GL20.GL_RGB, data[1].getWidth(), data[1].getHeight(), 0, GL20.GL_RGB, GL20.GL_UNSIGNED_BYTE, data[1].getPixels());

    Gdx.gl20.glTexImage2D(GL20.GL_TEXTURE_CUBE_MAP_POSITIVE_Y, 0, GL20.GL_RGB, data[2].getWidth(), data[2].getHeight(), 0, GL20.GL_RGB, GL20.GL_UNSIGNED_BYTE, data[2].getPixels());
    Gdx.gl20.glTexImage2D(GL20.GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, 0, GL20.GL_RGB, data[3].getWidth(), data[3].getHeight(), 0, GL20.GL_RGB, GL20.GL_UNSIGNED_BYTE, data[3].getPixels());

    Gdx.gl20.glTexImage2D(GL20.GL_TEXTURE_CUBE_MAP_POSITIVE_Z, 0, GL20.GL_RGB, data[4].getWidth(), data[4].getHeight(), 0, GL20.GL_RGB, GL20.GL_UNSIGNED_BYTE, data[4].getPixels());
    Gdx.gl20.glTexImage2D(GL20.GL_TEXTURE_CUBE_MAP_NEGATIVE_Z, 0, GL20.GL_RGB, data[5].getWidth(), data[5].getHeight(), 0, GL20.GL_RGB, GL20.GL_UNSIGNED_BYTE, data[5].getPixels());

    //Gdx.gl20.glGenerateMipmap(GL20.GL_TEXTURE_CUBE_MAP);
    //Gdx.gl20.glTexParameteri(GL20.GL_TEXTURE_CUBE_MAP, GL20.GL_TEXTURE_MIN_FILTER, GL20.GL_LINEAR);

    Gdx.gl20.glTexParameteri ( GL20.GL_TEXTURE_CUBE_MAP, GL20.GL_TEXTURE_MIN_FILTER,GL20.GL_LINEAR_MIPMAP_LINEAR );     
    Gdx.gl20.glTexParameteri ( GL20.GL_TEXTURE_CUBE_MAP, GL20.GL_TEXTURE_MAG_FILTER,GL20.GL_LINEAR );
    Gdx.gl20.glTexParameteri ( GL20.GL_TEXTURE_CUBE_MAP, GL20.GL_TEXTURE_WRAP_S, GL20.GL_CLAMP_TO_EDGE );
    Gdx.gl20.glTexParameteri ( GL20.GL_TEXTURE_CUBE_MAP, GL20.GL_TEXTURE_WRAP_T, GL20.GL_CLAMP_TO_EDGE );

    Gdx.gl20.glGenerateMipmap(GL20.GL_TEXTURE_CUBE_MAP);
}



public void render(Camera camera){

    //SPECIAL THANKS TO Jos van Egmond 
    camera.view.getRotation( q, true );
    q.conjugate();
    ///////////////////////////////////    
    worldTrans.idt();
    worldTrans.rotate(quaternion);

    shader.begin();     
    shader.setUniformMatrix(u_worldTrans, worldTrans.translate(0, 0, -1));

    quad.render(shader, GL20.GL_TRIANGLES);
    shader.end();
}

public Mesh createQuad(){
    Mesh mesh = new Mesh(true, 4, 6, VertexAttribute.Position(), VertexAttribute.  ColorUnpacked(), VertexAttribute.TexCoords(0));
        mesh.setVertices(new float[] 
        {-1f, -1f, 0, 1, 1, 1, 1, 0, 1,
        1f, -1f, 0, 1, 1, 1, 1, 1, 1,
        1f, 1f, 0, 1, 1, 1, 1, 1, 0,
        -1f, 1f, 0, 1, 1, 1, 1, 0, 0});
        mesh.setIndices(new short[] {0, 1, 2, 2, 3, 0});
        return mesh;
}

@Override
public void dispose() {
    shader.dispose();
    quad.dispose();
    for(int i=0; i<6; i++) 
        data[i].dispose();
}

}

如何使用它？只需创建它的实例：

EnvironmentCubemap envCubemap = new EnvironmentCubemap(Gdx.files.internal("cubemap/pos-x.png"), Gdx.files.internal("cubemap/neg-x.png"), 
            Gdx.files.internal("cubemap/pos-y.jpg"), Gdx.files.internal("cubemap/neg-y.jpg"), 
            Gdx.files.internal("cubemap/pos-z.png"), Gdx.files.internal("cubemap/neg-z.png"));

要么

EnvironmentCubemap envCubemap = new EnvironmentCubemap(new Pixmap(Gdx.files.internal("cubemap/all_in_one.jpg")));

然后使用其render方法：

envCubemap.render(camera);

希望对别人有帮助！