SMAA Enhanced Subpixel Morphological Antialiasing

엔씨소프트

이재윤

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| Abstract

• Image-based post-processing AA technique

– 좋은 edge detection

– Simple and effective way to handle sharpness

• Geometric features

• Diagonal lines

• Works with MSAA / SSAA

• CryEngine3에 적용

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| Introduction

• CG에서의 숙원사업 anti-aliasing

– Spatial domain

– Temporal domain

• MSAA/SSAA

– 이제는 진부한 퀄리티와 (메모리+속도)의 trade-off

• MLAA에서 착안

– Practical MLAA의 모든 step을 rebuilding

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| Previous MLAA

Original Image

Edges texture

Blending weights texture

Antialiased Image

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| SMAA

• Edge detection

– Local contrast adaptation

• Pattern handling

– Sharp geometric features

– Diagonal patterns

– Accurate distances search

• Sub-pixel rendering

• Temporal re-projection

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| Edge detection

• Luminance 사용

– RGB 보다 빠름

– Shading aliasing에도 적용 가능

• Top Right edge에 대해서만 검출

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| Edge detection

Crossing edges Using Local contrast SMAA

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| Edge detection

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| Pattern handling

No AA MLAA SMAA

• Sharp geometric features

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| Pattern handling

• Sharp geometric features

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| Pattern handling

• Sharp geometric features

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| Pattern handling

• Diagonal patterns

– 기존의 filter-based techniques

• Orthogonal pattern에 대해서만 고려

• 대각선에 대해 좋지 않은 aliased 결과

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| Pattern handling

• Diagonal patterns

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MLAA SMAA

| Pattern handling

• Diagonal patterns

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Pattern map Area texture

| Pattern handling

• Accurate distances search

– 정확한 edge dist.를 찾는 것이 key point

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| Sub-pixel rendering

MLAA

Single sample / pixel

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SMAA + @

More samples / pixel

| Sub-pixel rendering

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| Temporal Re-projection

• TSSAA

– sub-pixel rendering에 효과적

– But, ghosting artifact 존재

• Prev. frame re-projection

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| Temporal re-projection

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TSSAA Re-projection Velocity weighting

| Temporal re-projection

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TSSAA Re-projection Velocity weighting

| Results

• NVIDIA GeForce GTX 470

• 1080p Images

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techniques Execution times

SMAA 1x 1.02ms

SMAA T2x 1.32ms

SMAA S2x 2.04ms

SMAA 4x 2.34ms

| Conclusions

• Tackles all the weak points remaining in filter-

based antialiasing solutions

• Shown how to combine a filter-based AA with

MSAA/SSAA

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