我目前正在尝试让这个散景着色器与 GPUImage 一起使用：http://blenderartists.org/forum/showthread.php?237488-GLSL-depth-of-field-with-bokeh-v2-4-(update)
这就是我目前所拥有的：
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;
}
这是我的散景滤镜，GPUImageTwoInputFilter 的子类：
@implementation GPUImageBokehFilter
- (id)init;
{
NSString *fragmentShaderPathname = [[NSBundle mainBundle] pathForResource:@"BokehShader" ofType:@"fsh"];
NSString *fragmentShaderString = [NSString stringWithContentsOfFile:fragmentShaderPathname encoding:NSUTF8StringEncoding error:nil];
if (!(self = [super initWithFragmentShaderFromString:fragmentShaderString]))
{
return nil;
}
focalDepthUniform = [filterProgram uniformIndex:@"focalDepth"];
focalLengthUniform = [filterProgram uniformIndex:@"focalLength"];
fStopUniform = [filterProgram uniformIndex:@"fstop"];
[self setFocalDepth:1.0];
[self setFocalLength:35.0];
[self setFStop:2.2];
return self;
}
#pragma mark -
#pragma mark Accessors
- (void)setFocalDepth:(float)focalDepth {
_focalDepth = focalDepth;
[self setFloat:_focalDepth forUniform:focalDepthUniform program:filterProgram];
}
- (void)setFocalLength:(float)focalLength {
_focalLength = focalLength;
[self setFloat:_focalLength forUniform:focalLengthUniform program:filterProgram];
}
- (void)setFStop:(CGFloat)fStop {
_fStop = fStop;
[self setFloat:_fStop forUniform:fStopUniform program:filterProgram];
}
@end
最后，这就是我使用上述过滤器的方式：
@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];
}
...
第一个图像是我要模糊的那个，第二个是随机渐变来测试着色器的深度图的东西：
当我在我的 iPhone 上启动应用程序时，我得到了这个：
移动滑块（触发 dataInputChanged 方法）后，我得到这个：
虽然这看起来比第一张图片要好得多，但我仍然有一些问题：
- 有一条对角噪声线（在我放在图片上的红线内）似乎不模糊。
- 图像的左上角是模糊的，尽管它不应该如此。
为什么我会出现这种奇怪的行为？着色器输出不应该每次都相同吗？另外，我如何让它尊重深度图？我的 GLSL 着色器知识非常有限，所以请耐心等待。
