DOF, depth of field

1. Depth of Field
http://ozlael.egloos.com/

2. DOF 란
● 피사계심도
● 사진 렌즈로 어떤 거리의 피사체에 초점을
맞추면 그 앞쪽 [ 近點 ] 과 뒤쪽 [ 遠點 ] 의
일정한 거리 내에 초점이 맞는데 이때 그 범
위를 이르는 말 .
● PhotoRealistic Rendering

3. Pinhole Camera Model

4. Thin Lens Camera Model

5. Implementation
● Simulation of CoC
● Pass 1 : Scene Rendering
● Pass 2 : Pos-processing

6. Pass 1 : Scene Rendering
● 장면 랜더링
● Depth and Blurriness factor
● MRT 사용

7. Pass 1 : Scene Rendering
● Depth

8. Pass 1 : Scene Rendering
● Mapping Depth to Blur
Focal Range
1 Blur
Depth
-1
Focal Dist
float blur = saturate( abs( depth - focalDist) * (2/focalRange));

9. Pass 1 : Scene Rendering
● MRT output

10. Pass 2 : Pos-processing
● Use CoC
● Poisson distribution

11. Pass 2 : Pos-processing
● Blurriness 와 Filter Size

12. Pass 2 : Pos-processing
● Leaking

13. Pass 2 : Pos-processing
// Get center sample
float4 colorSum = tex2D(SceneColorSampler, v.vTexCoord);
float2 centerDepthBlur = tex2D(DepthBlurSampler, v.vTexCoord);
// Compute CoC size based on blurriness
float sizeCoC = centerDepthBlur.y * maxCoC;
float totalContribution = 1.0f;
// Run through all taps
for (int i = 0; i < NUM_DOF_TAPS; i++)
{
// Compute tap coordinates
float2 tapCoord = v.vTexCoord + filterTaps[i] * sizeCoC;
// Fetch tap sample
float4 tapColor = tex2D(SceneColorSampler, tapCoord);
float2 tapDepthBlur = tex2D(DepthBlurSampler, tapCoord);
// Compute tap contribution
float tapContribution = (tapDepthBlur.x > centerDepthBlur.x) ? 탭의 깊이 비교
1.0f : tapDepthBlur.y;
// Accumulate color and contribution 샘플링 탭이 Blurriness 0 면 색이 적용 X
colorSum += tapColor * tapContribution;
totalContribution += tapContribution;
}
// Normalize to get proper luminance
float4 finalColor = colorSum / totalContribution;