深度测试无法使用openGL ES

Question

我有一个正在屏幕上绘制的多维数据集，我激活了深度测试以使其不透明，但事实是，在多维数据集的正面和背面，它看起来不错。 但是当平移和旋转多维数据集时，结果很奇怪，这里有一些照片可以演示：

面前：

双方：

这种透视效果当然不受欢迎。

这是一些相关的代码：

指数和顶点：

const Vertex Vertices[] = {
    {{1, -1, 0}, {1, 1, 1, 1}, {1, 0}},
    {{1, 1, 0}, {1, 1, 1, 1}, {1, 1}},
    {{-1, 1, 0}, {1, 1, 1, 1}, {0, 1}},
    {{-1, -1, 0}, {1, 1, 1, 1}, {0, 0}},
    {{1, -1, -1}, {1, 1, 1, 1}, {1, 0}},
    {{1, 1, -1}, {1, 1, 1, 1}, {1, 1}},
    {{-1, 1, -1}, {1, 1, 1, 1}, {0, 1}},
    {{-1, -1, -1}, {1, 1, 1, 1}, {0, 0}}
};

const GLubyte Indices[] = {
    // Front
    0, 1, 2
    ,2, 3, 0,
    // Back
    4, 6, 5,
    4, 7, 6,
    // Left
    2, 7, 3,
    7, 6, 2,
    // Right
    0, 4, 1,
    4, 1, 5,
    // Top
    6, 2, 1,
    1, 6, 5,
    // Bottom
    0, 3, 7,
    0, 7, 4,
};

图层设置：

- (void)setupLayer {
    _eaglLayer = (CAEAGLLayer*) self.layer;
    _eaglLayer.opaque = YES;
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_NEVER);
}

深度缓冲区设置：

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

渲染：

- (void)render:(CADisplayLink*)displayLink {
    glClearColor(0, 0, 0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glEnable(GL_DEPTH_TEST);

    CC3GLMatrix *projection = [CC3GLMatrix matrix];
    float h = 4.0f * self.frame.size.height / self.frame.size.width;
    [projection populateFromFrustumLeft:-2 andRight:2 andBottom:-h/2 andTop:h/2 andNear:4 andFar:10];
    glUniformMatrix4fv(_projectionUniform, 1, 0, projection.glMatrix);

    CC3GLMatrix *modelView = [CC3GLMatrix matrix];
    [modelView populateFromTranslation:CC3VectorMake(sin(CACurrentMediaTime()), 0, -5)];
    _currentRotation += displayLink.duration * 90;
    [modelView rotateBy:CC3VectorMake(_currentRotation, _currentRotation, 0)];
    glUniformMatrix4fv(_modelViewUniform, 1, 0, modelView.glMatrix);

    glViewport(0, 0, self.frame.size.width, self.frame.size.height);

    glVertexAttribPointer(_positionSlot, 3, GL_FLOAT, GL_FALSE,
                          sizeof(Vertex), 0);
    glVertexAttribPointer(_colorSlot, 4, GL_FLOAT, GL_FALSE,
                          sizeof(Vertex), (GLvoid*) (sizeof(float)* 3));
    glVertexAttribPointer(_texCoordSlot, 2, GL_FLOAT, GL_FALSE,
                          sizeof(Vertex), (GLvoid*) (sizeof(float) * 7));


    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, _floorTexture);
    glUniform1i(_textureUniform, 0);

    glDrawElements(GL_TRIANGLE_STRIP, sizeof(Indices)/sizeof(Indices[0]),
                   GL_UNSIGNED_BYTE, 0);

    [_context presentRenderbuffer:GL_RENDERBUFFER];
}

编辑：

添加纹理映射功能：

- (GLuint)setupTexture:(NSString *)fileName {
    // 1
    CGImageRef spriteImage = [UIImage imageNamed:fileName].CGImage;
    if (!spriteImage) {
        NSLog(@"Failed to load image %@", fileName);
        exit(1);
    }

        // 2
    size_t width = CGImageGetWidth(spriteImage);
    size_t height = CGImageGetHeight(spriteImage);


    GLubyte * spriteData = (GLubyte *) calloc(width*height*4, sizeof(GLubyte));


    CGContextRef spriteContext = CGBitmapContextCreate(spriteData, width, height, 8, width*4,
                                                       CGImageGetColorSpace(spriteImage), kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);

    // 3
    CGContextDrawImage(spriteContext, CGRectMake(0, 0, width, height), spriteImage);

    CGContextRelease(spriteContext);

    // 4
    GLuint texName;
    glGenTextures(1, &texName);
    glBindTexture(GL_TEXTURE_2D, texName);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, spriteData);

    free(spriteData);  
    return texName;    
}

我在这儿做错了什么？

Answer 1

glDepthFunc(GL_NEVER); -至少将其替换为GL_LEQUAL 。