Ios 前两个片段着色器输出不同

Ios 前两个片段着色器输出不同,ios,glsl,gpuimage,fragment-shader,glsles,Ios,Glsl,Gpuimage,Fragment Shader,Glsles,我目前正在尝试使此bokeh着色器与GPUImage一起工作: 这就是我目前得到的: precision mediump float; varying highp vec2 textureCoordinate; varying highp vec2 textureCoordinate2; uniform sampler2D inputImageTexture; uniform sampler2D inputImageTexture2; uniform float inputImageTextu

我目前正在尝试使此bokeh着色器与GPUImage一起工作:

这就是我目前得到的:

precision mediump float;

varying highp vec2 textureCoordinate;
varying highp vec2 textureCoordinate2;
uniform sampler2D inputImageTexture;
uniform sampler2D inputImageTexture2;
uniform float inputImageTextureWidth;
uniform float inputImageTextureHeight;

#define PI 3.14159265

float width = inputImageTextureWidth; //texture width
float height = inputImageTextureHeight; //texture height

vec2 texel = vec2(1.0/width,1.0/height);

//uniform variables from external script

uniform float focalDepth;  //focal distance value in meters, but you may use autofocus option below
uniform float focalLength; //focal length in mm
uniform float fstop; //f-stop value
bool showFocus = false; //show debug focus point and focal range (red = focal point, green = focal range)

float znear = 0.1; //camera clipping start
float zfar = 5.0; //camera clipping end

//------------------------------------------
//user variables

int samples = 3; //samples on the first ring
int rings = 3; //ring count

bool manualdof = false; //manual dof calculation
float ndofstart = 1.0; //near dof blur start
float ndofdist = 2.0; //near dof blur falloff distance
float fdofstart = 1.0; //far dof blur start
float fdofdist = 3.0; //far dof blur falloff distance

float CoC = 0.03;//circle of confusion size in mm (35mm film = 0.03mm)

bool vignetting = false; //use optical lens vignetting?
float vignout = 1.3; //vignetting outer border
float vignin = 0.0; //vignetting inner border
float vignfade = 22.0; //f-stops till vignete fades

bool autofocus = false; //use autofocus in shader? disable if you use external focalDepth value
vec2 focus = vec2(0.5, 0.5); // autofocus point on screen (0.0,0.0 - left lower corner, 1.0,1.0 - upper right)
float maxblur = 1.0; //clamp value of max blur (0.0 = no blur,1.0 default)

float threshold = 0.5; //highlight threshold;
float gain = 2.0; //highlight gain;

float bias = 0.5; //bokeh edge bias
float fringe = 0.7; //bokeh chromatic aberration/fringing

bool noise = false; //use noise instead of pattern for sample dithering
float namount = 0.0001; //dither amount

bool depthblur = false; //blur the depth buffer?
float dbsize = 1.25; //depthblursize

/*
 next part is experimental
 not looking good with small sample and ring count
 looks okay starting from samples = 4, rings = 4
 */

bool pentagon = false; //use pentagon as bokeh shape?
float feather = 0.4; //pentagon shape feather

//------------------------------------------


float penta(vec2 coords) //pentagonal shape
{
    float scale = float(rings) - 1.3;
    vec4  HS0 = vec4( 1.0,         0.0,         0.0,  1.0);
    vec4  HS1 = vec4( 0.309016994, 0.951056516, 0.0,  1.0);
    vec4  HS2 = vec4(-0.809016994, 0.587785252, 0.0,  1.0);
    vec4  HS3 = vec4(-0.809016994,-0.587785252, 0.0,  1.0);
    vec4  HS4 = vec4( 0.309016994,-0.951056516, 0.0,  1.0);
    vec4  HS5 = vec4( 0.0        ,0.0         , 1.0,  1.0);

    vec4  one = vec4( 1.0 );

    vec4 P = vec4((coords),vec2(scale, scale));

    vec4 dist = vec4(0.0);
    float inorout = -4.0;

    dist.x = dot( P, HS0 );
    dist.y = dot( P, HS1 );
    dist.z = dot( P, HS2 );
    dist.w = dot( P, HS3 );

    dist = smoothstep( -feather, feather, dist );

    inorout += dot( dist, one );

    dist.x = dot( P, HS4 );
    dist.y = HS5.w - abs( P.z );

    dist = smoothstep( -feather, feather, dist );
    inorout += dist.x;

    return clamp( inorout, 0.0, 1.0 );
}

float bdepth(vec2 coords) //blurring depth
{
    float d = 0.0;
    float kernel[9];
    vec2 offset[9];

    vec2 wh = vec2(texel.x, texel.y) * dbsize;

    offset[0] = vec2(-wh.x,-wh.y);
    offset[1] = vec2( 0.0, -wh.y);
    offset[2] = vec2( wh.x -wh.y);

    offset[3] = vec2(-wh.x,  0.0);
    offset[4] = vec2( 0.0,   0.0);
    offset[5] = vec2( wh.x,  0.0);

    offset[6] = vec2(-wh.x, wh.y);
    offset[7] = vec2( 0.0,  wh.y);
    offset[8] = vec2( wh.x, wh.y);

    kernel[0] = 1.0/16.0;   kernel[1] = 2.0/16.0;   kernel[2] = 1.0/16.0;
    kernel[3] = 2.0/16.0;   kernel[4] = 4.0/16.0;   kernel[5] = 2.0/16.0;
    kernel[6] = 1.0/16.0;   kernel[7] = 2.0/16.0;   kernel[8] = 1.0/16.0;


    for( int i=0; i<9; i++ )
    {
        float tmp = texture2D(inputImageTexture2, coords + offset[i]).r;
        d += tmp * kernel[i];
    }

    return d;
}


vec3 color(vec2 coords,float blur) //processing the sample
{
    vec3 col = vec3(0.0);

    col.r = texture2D(inputImageTexture, coords + vec2(0.0,1.0)*texel*fringe*blur).r;
    col.g = texture2D(inputImageTexture, coords + vec2(-0.866,-0.5)*texel*fringe*blur).g;
    col.b = texture2D(inputImageTexture, coords + vec2(0.866,-0.5)*texel*fringe*blur).b;

    vec3 lumcoeff = vec3(0.299,0.587,0.114);
    float lum = dot(col.rgb, lumcoeff);
    float thresh = max((lum-threshold)*gain, 0.0);
    return col+mix(vec3(0.0),col,thresh*blur);
}

vec2 rand(vec2 coord) //generating noise/pattern texture for dithering
{
    float noiseX = ((fract(1.0-coord.s*(width/2.0))*0.25)+(fract(coord.t*(height/2.0))*0.75))*2.0-1.0;
    float noiseY = ((fract(1.0-coord.s*(width/2.0))*0.75)+(fract(coord.t*(height/2.0))*0.25))*2.0-1.0;

    if (noise)
    {
        noiseX = clamp(fract(sin(dot(coord ,vec2(12.9898,78.233))) * 43758.5453),0.0,1.0)*2.0-1.0;
        noiseY = clamp(fract(sin(dot(coord ,vec2(12.9898,78.233)*2.0)) * 43758.5453),0.0,1.0)*2.0-1.0;
    }
    return vec2(noiseX,noiseY);
}

vec3 debugFocus(vec3 col, float blur, float depth)
{
    float edge = 0.002*depth; //distance based edge smoothing
    float m = clamp(smoothstep(0.0,edge,blur),0.0,1.0);
    float e = clamp(smoothstep(1.0-edge,1.0,blur),0.0,1.0);

    col = mix(col,vec3(1.0,1.0,0.0),(1.0-m)*0.6);
    col = mix(col,vec3(0.0,1.0,1.0),((1.0-e)-(1.0-m))*0.2);

    return col;
}

float linearize(float depth)
{
    return -zfar * znear / (depth * (zfar - znear) - zfar);
}

float vignette()
{
    float dist = distance(textureCoordinate.xy, vec2(0.5,0.5));
    dist = smoothstep(vignout+(fstop/vignfade), vignin+(fstop/vignfade), dist);
    return clamp(dist,0.0,1.0);
}

void main()
{
    //scene depth calculation

    float depth = linearize(texture2D(inputImageTexture2, textureCoordinate2.xy).x);

    if (depthblur)
    {
        depth = linearize(bdepth(textureCoordinate2.xy));
    }

    //focal plane calculation

    float fDepth = focalDepth;

    if (autofocus)
    {
        fDepth = linearize(texture2D(inputImageTexture2, focus).x);
    }

    //dof blur factor calculation

    float blur = 0.0;

    if (manualdof)
    {
        float a = depth-fDepth; //focal plane
        float b = (a-fdofstart)/fdofdist; //far DoF
        float c = (-a-ndofstart)/ndofdist; //near Dof
        blur = (a>0.0)?b:c;
    }

    else
    {
        float f = focalLength; //focal length in mm
        float d = fDepth*1000.0; //focal plane in mm
        float o = depth*1000.0; //depth in mm

        float a = (o*f)/(o-f);
        float b = (d*f)/(d-f);
        float c = (d-f)/(d*fstop*CoC);

        blur = abs(a-b)*c;
    }

    blur = clamp(blur,0.0,1.0);

    // calculation of pattern for ditering

    vec2 noise = rand(textureCoordinate.xy)*namount*blur;

    // getting blur x and y step factor

    float w = (1.0/width)*blur*maxblur+noise.x;
    float h = (1.0/height)*blur*maxblur+noise.y;

    // calculation of final color

    vec3 col = vec3(0.0);

    if(blur < 0.05) //some optimization thingy
    {
        col = texture2D(inputImageTexture, textureCoordinate.xy).rgb;
    }

    else
    {
        col = texture2D(inputImageTexture, textureCoordinate.xy).rgb;
        float s = 1.0;
        int ringsamples;

        for (int i = 1; i <= rings; i += 1)
        {
            ringsamples = i * samples;

            for (int j = 0 ; j < ringsamples ; j += 1)
            {
                float step = PI*2.0 / float(ringsamples);
                float pw = (cos(float(j)*step)*float(i));
                float ph = (sin(float(j)*step)*float(i));
                float p = 1.0;
                if (pentagon)
                {
                    p = penta(vec2(pw,ph));
                }
                col += color(textureCoordinate.xy + vec2(pw*w,ph*h),blur)*mix(1.0,(float(i))/(float(rings)),bias)*p;
                s += 1.0*mix(1.0,(float(i))/(float(rings)),bias)*p;
            }
        }
        col /= s; //divide by sample count
    }

    if (showFocus)
    {
        col = debugFocus(col, blur, depth);
    }

    if (vignetting)
    {
        col *= vignette();
    }

    gl_FragColor.rgb = col;
    gl_FragColor.a = 1.0;
}
最后,这是我如何使用上述过滤器:

@implementation ViewController {
    GPUImageBokehFilter *bokehFilter;
    GPUImagePicture *bokehMap;
    UIImage *inputImage;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    inputImage = [UIImage imageNamed:@"stones"];
    bokehMap = [[GPUImagePicture alloc] initWithImage:[UIImage imageNamed:@"bokehmask"]];
    _backgroundImage.image = inputImage;

    bokehFilter = [[GPUImageBokehFilter alloc] init];

    [self processImage];
}
- (IBAction)dataInputUpdated:(id)sender {
    [self processImage];
}
- (void *)processImage {
    dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        GPUImagePicture *gpuPicture = [[GPUImagePicture alloc] initWithImage:inputImage];
        [gpuPicture addTarget:bokehFilter];
        [gpuPicture processImage];
        [bokehMap addTarget:bokehFilter];
        [bokehMap processImage];
        [bokehFilter useNextFrameForImageCapture];
        [bokehFilter setFloat:inputImage.size.width forUniformName:@"inputImageTextureWidth"];
        [bokehFilter setFloat:inputImage.size.height forUniformName:@"inputImageTextureHeight"];

        UIImage *blurredImage = [bokehFilter imageFromCurrentFramebuffer];
        dispatch_async(dispatch_get_main_queue(), ^{
            [self displayNewImage:blurredImage];
        });
    });
}
- (void)displayNewImage:(UIImage*)newImage {
    [UIView transitionWithView:_backgroundImage
                      duration:.6f
                       options:UIViewAnimationOptionTransitionCrossDissolve
                    animations:^{
                        _backgroundImage.image = newImage;
                    } completion:nil];
}

...
第一个图像是我试图模糊的,第二个是随机渐变,用于测试着色器的深度贴图:

当我在iPhone上启动应用程序时,我得到以下信息:

移动滑块(触发dataInputChanged方法)后,我得到以下结果:

虽然这张照片看起来比第一张照片要好得多,但我仍然有一些问题:

  • 有一条对角线(在我放在图片上的红线内)看起来是不模糊的
  • 图像的左上角是模糊的,即使它不应该是模糊的
  • 为什么我会有这种奇怪的行为?着色器输出不应该每次都相同吗?
    还有,我如何让它尊重深度图?我的GLSL着色器知识非常有限,因此请耐心等待。

    对角线伪影似乎是由测试梯度造成的。你可以看到它发生在渐变变成完全白色的地方。尝试展开渐变,使其仅在图像的每个角落达到1.0或0.0。

    是否尝试启用
    showFocus
    ?这将以红色显示焦点,以绿色显示焦距,这将有助于调试。您还可以尝试启用
    自动对焦
    ,以确保图像的中心处于对焦状态,因为此时由于
    线性化功能改变坐标系,不清楚应该对焦的距离。然后尝试调整
    fstop
    以获得所需的模糊量。您可能还会发现需要大于
    samples=3
    rings=3
    才能产生平滑的波基效果

    这是一个相当大的问题,我不能给出完整的答案,因为我真的需要测试一下

    但有几点:你最后的形象很难处理。因为图像放大了这么多,我无法判断它是真的模糊了,还是因为分辨率的原因看起来模糊了。不管怎样,您得到的模糊量(与您提供的原始链接相比)表明着色器不起作用

    我关心的另一件事是
    //一些优化内容
    注释。这类事情将导致最终输出中出现丑陋的线条。说你在
    blur<0.05
    下不会有任何模糊不一定是你能做到的!当着色器从模糊着色器过渡到“优化”部分时,我预计会出现令人讨厌的伪影


    希望能给你带来光明,祝你好运

    你的回答帮助我走上了正确的道路,在花了几个小时摆弄我的代码和着色器之后,我设法修复了所有的bug。以下是导致它们的原因以及我是如何修复它们的:

    丑陋的对角线是由
    线性化()
    方法造成的,因此我将其删除,并使着色器使用深度贴图中的RGB值(或者更精确地说,仅使用R值),而不首先处理它们

    我从着色器中得到的蓝色图像是由我自己的无能造成的。这两行必须放在调用
    processImage
    之前:

    [bokehFilter setFloat:inputImage.size.width forUniformName:@"inputImageTextureWidth"];
    [bokehFilter setFloat:inputImage.size.height forUniformName:@"inputImageTextureHeight"];
    
    事后看来,很明显为什么我只在第二次使用着色器时才得到结果。在修复了这些bug之后,我继续对它进行了一些优化,以尽可能减少执行时间,现在我可以告诉它渲染8个样本/4个环,它可以在不到一秒钟的时间内完成。下面是它的样子:


    谢谢大家的回答,如果没有你们,我可能无法修复这些bug。

    首先映入我眼帘的是
    [bokehMap processImage]
    [bokehFilter使用下一帧进行图像捕获]的顺序错误。它们需要翻转,以便在触发更新过滤器输出的处理之前告诉过滤器您将从中捕获。试着换一下,看看会发生什么。除此之外,这是一个非常昂贵的着色器,我想用一个三输入过滤器来代替它,该过滤器还可以接收高斯模糊版本的图像进行混合(就像倾斜移位一样),这样效果会更好。我翻转了两个方法调用,只得到了相同的结果。另外,我知道这个着色器很昂贵,但我对着色器了解不够,无法简化它。我能在没有帮助的情况下走到这一步真是奇迹D如果有人知道他们在做什么,把它清理干净,并使它成为GPUImage的“官方”部分,那就太好了。(还有,继续努力!GPUImage让我学会了碎片着色器的基础知识,这是我拖延太久的事情),这就违背了一开始就有深度图的目的。你是什么意思?我是说你仍然使用渐变,只是不要让它夹在图像中间的1或0。尝试在你的图像上叠加你的渐变(在photoshop或其他软件中);你会明白我的意思。我需要那些纯白/黑色区域,因为它们告诉着色器什么要完全聚焦,什么要模糊。如果我听从你的建议,着色器会模糊所有东西,除了图像角落中渐变达到1.0的一小部分。哦,好的。我对着色器的理解还不够透彻,不知道具体的原因,但渐变的形状肯定是造成伪影的原因——当渐变接近0.0或1.0时,会有一条“边”。如果你把它看作是信号处理,边缘是高频变化。着色器需要过滤掉它们;着色器需要在每个点周围进行更多采样。为了避免这种变化,您可以尝试平滑渐变(而不是线性渐变);S曲线梯度(我忘了
    
    [bokehFilter setFloat:inputImage.size.width forUniformName:@"inputImageTextureWidth"];
    [bokehFilter setFloat:inputImage.size.height forUniformName:@"inputImageTextureHeight"];