將帶紋理的3D模型從.obj文件導入到iOS OpenGl ES 2.0

Question

我目前正在嘗試將具有紋理的.obj格式的3D模型轉換為與Objective c兼容的代碼，並使用OpenGL ES 2.0進行渲染。

我正在使用Heiko Behrens的[obj2opengl] [1]將3d模型轉換為頭文件

3d模型具有此紋理圖像的UV貼圖。

一切都幾乎工作，但不知何故，紋理不能正確渲染和我的立方體顯示像這樣 。

我已經嘗試過各種方法，但是無法弄清楚我在做什么錯，或者我只是不明白。

這是我如何渲染多維數據集的代碼：

unsigned int boxNumVerts = 36;

float boxVerts [] = {
  // f 1/1/1 2/2/1 3/3/1 4/4/1 
  -0.5, -0.5, 0.5,
  -0.5, -0.5, -0.5,
  0.5, -0.5, -0.5,
  // f 1/1/1 2/2/1 3/3/1 4/4/1 
  -0.5, -0.5, 0.5,
  0.5, -0.5, 0.5,
  0.5, -0.5, -0.5,
  // f 5/5/2 6/6/2 7/7/2 8/8/2 
  -0.5, 0.5, 0.5,
  0.5, 0.5, 0.5,
  0.5, 0.5, -0.5,
  // f 5/5/2 6/6/2 7/7/2 8/8/2 
  -0.5, 0.5, 0.5,
  -0.5, 0.5, -0.5,
  0.5, 0.5, -0.5,
  // f 1/9/3 4/10/3 6/6/3 5/5/3 
  -0.5, -0.5, 0.5,
  0.5, -0.5, 0.5,
  0.5, 0.5, 0.5,
  // f 1/9/3 4/10/3 6/6/3 5/5/3 
  -0.5, -0.5, 0.5,
  -0.5, 0.5, 0.5,
  0.5, 0.5, 0.5,
  // f 4/11/4 3/12/4 7/7/4 6/6/4 
  0.5, -0.5, 0.5,
  0.5, -0.5, -0.5,
  0.5, 0.5, -0.5,
  // f 4/11/4 3/12/4 7/7/4 6/6/4 
  0.5, -0.5, 0.5,
  0.5, 0.5, 0.5,
  0.5, 0.5, -0.5,
  // f 3/13/5 2/14/5 8/8/5 7/7/5 
  0.5, -0.5, -0.5,
  -0.5, -0.5, -0.5,
  -0.5, 0.5, -0.5,
  // f 3/13/5 2/14/5 8/8/5 7/7/5 
  0.5, -0.5, -0.5,
  0.5, 0.5, -0.5,
  -0.5, 0.5, -0.5,
  // f 2/2/6 1/1/6 5/5/6 8/8/6 
  -0.5, -0.5, -0.5,
  -0.5, -0.5, 0.5,
  -0.5, 0.5, 0.5,
  // f 2/2/6 1/1/6 5/5/6 8/8/6 
  -0.5, -0.5, -0.5,
  -0.5, 0.5, -0.5,
  -0.5, 0.5, 0.5,
};


float boxTexCoords [] = {
  // f 1/1/1 2/2/1 3/3/1 4/4/1 
  0.5016, 0.7508,
  0.2504, 0.7508,
  0.2504, 1.002,
  // f 1/1/1 2/2/1 3/3/1 4/4/1 
  0.5016, 0.7508,
  0.5016, 1.002,
  0.2504, 1.002,
  // f 5/5/2 6/6/2 7/7/2 8/8/2 
  0.5016, 0.4996,
  0.5016, 0.2484,
  0.2504, 0.2484,
  // f 5/5/2 6/6/2 7/7/2 8/8/2 
  0.5016, 0.4996,
  0.2504, 0.4996,
  0.2504, 0.2484,
  // f 1/9/3 4/10/3 6/6/3 5/5/3 
  0.7528, 0.4996,
  0.7528, 0.2484,
  0.5016, 0.2484,
  // f 1/9/3 4/10/3 6/6/3 5/5/3 
  0.7528, 0.4996,
  0.5016, 0.4996,
  0.5016, 0.2484,
  // f 4/11/4 3/12/4 7/7/4 6/6/4 
  0.5016, -0.00279999999999991,
  0.2504, -0.00279999999999991,
  0.2504, 0.2484,
  // f 4/11/4 3/12/4 7/7/4 6/6/4 
  0.5016, -0.00279999999999991,
  0.5016, 0.2484,
  0.2504, 0.2484,
  // f 3/13/5 2/14/5 8/8/5 7/7/5 
  -0.0008, 0.2484,
  -0.0008, 0.4996,
  0.2504, 0.4996,
  // f 3/13/5 2/14/5 8/8/5 7/7/5 
  -0.0008, 0.2484,
  0.2504, 0.2484,
  0.2504, 0.4996,
  // f 2/2/6 1/1/6 5/5/6 8/8/6 
  0.2504, 0.7508,
  0.5016, 0.7508,
  0.5016, 0.4996,
  // f 2/2/6 1/1/6 5/5/6 8/8/6 
  0.2504, 0.7508,
  0.2504, 0.4996,
  0.5016, 0.4996,
};

和我的渲染代碼：

-(void)setup
{
    self.drawingMode = GL_TRIANGLES;
    vertexData = [NSMutableData dataWithBytes:boxVerts length:sizeof(float)*boxNumVerts*3];
    textureCoordinateData = [NSMutableData dataWithBytes:boxTexCoords length:sizeof(float)*boxNumVerts*2];
    //    vertexNormalData = [NSMutableData dataWithBytes:PrisonCellNormals length:sizeof(float)*PrisonCellNumVerts*3];
}

-(void)renderInScene:(FRPGScene *)_scene 
{
     if (texture != nil)
        {
            effect.texture2d0.envMode = GLKTextureEnvModeReplace;
            effect.texture2d0.target = GLKTextureTarget2D;
            effect.texture2d0.name = texture.name;
            [effect.texture2d0 setEnabled:YES];
        }

        effect.transform.modelviewMatrix = self.modelviewMatrix;
        effect.transform.projectionMatrix = _scene.projectionMatrix;

        [effect prepareToDraw];

        // setup
        glEnable(GL_BLEND);

        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

        glEnableVertexAttribArray(GLKVertexAttribPosition);

        glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, 0, self.vertices);

        if (!useConstantColor)
        {
            glEnableVertexAttribArray(GLKVertexAttribColor);
            glVertexAttribPointer(GLKVertexAttribColor, 4, GL_FLOAT, GL_FALSE, 0, self.vertexColors);
        }

        if (texture != nil)
        {
            glEnableVertexAttribArray(GLKVertexAttribTexCoord0);
            glVertexAttribPointer(GLKVertexAttribTexCoord0, 2, GL_FLOAT, GL_FALSE, 0, self.textureCoordinates);
        }

        glDrawArrays(drawingMode, 0, self.numVertices);

        glDisable(GL_BLEND);

        // teardown
        glDisableVertexAttribArray(GLKVertexAttribPosition);

        if (!useConstantColor)
        {
            glDisableVertexAttribArray(GLKVertexAttribColor);
        }

        if (texture != nil)
        {
            glDisableVertexAttribArray(GLKVertexAttribTexCoord0);
        }
}

更新：我在其中設置上下文的appDelegate函數。

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    EAGLContext *context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
    [EAGLContext setCurrentContext:context];

    GLKView *view = [[GLKView alloc] initWithFrame:[[UIScreen mainScreen] bounds] context:context];
    view.delegate = self; //Makes sure the views drawInRect is called

    FRPGViewController *controller = [[FRPGViewController alloc] init];
    controller.delegate = self;
    controller.view = view;

    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.rootViewController = controller;
    [self.window makeKeyAndVisible];

    scene = [[FRPGTestLevel alloc] init];

    //Set screen aspect ratio boundaries ipad 4:3 iphone 3:2
    CGRect rect = view.bounds;

    scene.left = -100.0f;
    scene.right = 100.0f;
    scene.bottom = -100.0f / (rect.size.width / rect.size.height); // -75.0..
    scene.top = 100.0f / (rect.size.width / rect.size.height); // 75.0..
    [scene setup];

    [controller setScene:scene];


    return YES;
}

我的場景渲染函數清除緩沖區並在每個對象上調用上述renderInScene方法

-(void)render
{
     glClearColor(clearColor.r, clearColor.g, clearColor.b, clearColor.a);
     glClear(GL_COLOR_BUFFER_BIT);
     [object renderInScene:scene]; 
}  

Answer 1

您需要設置深度緩沖區

GLuint _depthRenderBuffer;

- (void)setupDepthBuffer
{
    glGenRenderbuffers(1, &_depthRenderBuffer);
    glBindRenderbuffer(GL_RENDERBUFFER, _depthRenderBuffer);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, self.frame.size.width, self.frame.size.height);
}

然后添加到您的幀緩沖區

glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, _depthRenderBuffer);