Unity3D图像后处理特效——Antialiasing (PostEffect)

The Antialiasing (PostEffect) offers a set of algorithms designed to give a smoother appearance to graphics. When two areas of different colour adjoin in an image, the shape of the
pixels can form a very distinctive "staircase" along the boundary. This effect is known asaliasing and hence antialiasing refers to any measure which reduces the effect.
反走样 (后处理特效)提供了一套旨在提供更柔顺的图形表现的算法。当两个不同颜色的区域在图像中相邻时，边界像素的形状会形成一个非常独特"楼梯"。这种效应被称为锯齿，因此反走样是指指任何可降低锯齿效果的措施。



The cube on the left is rendered without antialiasing while the one on the right shows the effect of the FXAA1PresetB algorithm
左边的立方体并没有使用反走样技术来进行渲染，而右边的立方体使用基于FXAA1PresetB算法的反走样技术。
 
The antialiasing algorithms are image based, which is very useful for deferred rendering where traditional multisampling is not properly supported. The algorithms currently supported are
NVIDIA's FXAA, FXAA II, FXAA III (tweakable and console optimized), simpler edge blurs (NFAA, SSAA) that blur only local edges and an adaption of the DLAA algorithm that also addresses long edges. SSAA is the fastest technique, followed by NFAA, FXAAII, FXAA
II, DLAA and the the other FXAA's. Typically, the quality of antialiasing trades off against the speed of the algorithm but there may be situations where the choice of algorithm makes little difference.

反走样算法是基于图像的，这使得它在传统多级采样不支持的情况下非常适用于延迟渲染。目前支持的算法有NVIDIA的FXAA、FXAA II、FXAA
III（tweakable 和优化的控制台），简单的仅模糊局部边界的边缘模糊算法（NFAA，SSAA）以及自适应地处理长边界的DLAA算法。SSAA是一种最快的反走样技术，接下来是NFAA、FXAA
III、FXAA II、DLAA和其他FXAA算法。通常情况下，反走样效果的质量好坏与算法的速度成反比，但也有时候算法的选择并不会造成多大的差异。

 

For those especially interested in console and NaCl deployment, the optimizedFXAA III implementation offers the best tradeoff between quality and performance and can furthermore
be tweaked towards sharper or blurrier looks.

对于那些对控制台和NaCl发布比较敏感的图像，优化过的 FXAA III算法提供的质量和性能之间的最佳平衡，此外还可以变得加更清晰或模糊。
 
As with the otherimage effects,
this effect is only available in Unity Pro and you must have the Pro Standard Assets
installed before it becomes available.

跟其他图像后处理特效一样，该特效目前只在Unity Pro版本中有效，而且在使用之前必须要安装Pro
Standard Assets。

 

Properties   属性

AA Technique 反走样技术

The algorithm to be used. 使用算法

 

Hardware support    硬件支持

This effect requires a graphics card with pixel shaders (3.0) or OpenGL ES 2.0. PC: NVIDIA cards since 2004 (GeForce 6), AMD cards since 2005 (Radeon X1300), Intel cards since 2006 (GMA X3000);
Mobile: OpenGL ES 2.0; Consoles: Xbox 360, PS3.

该特效要求在拥有像素着色器（3.0）或OpenGL ES2.0的显卡上进行。PC：2004年以后的NVIDIA卡（GeForce6），2005年以后的AMD卡（Radeon
X1300），2006年以后的Intel卡（GMA X3000）；移动设备：OpenGL ES2.0；控制台：Xbox360，PS3。

 

All image effects automatically disable themselves when they can not run on end-users graphics card.

所有图像特效如果不能在用户终端的显卡上运行时则会自动关闭。