Rand at 22:31, 1 January 2012

2012-01-01T22:31:27Z

Rand at 22:28, 1 January 2012

2012-01-01T22:28:25Z

Rand: New page: NOTOC NOEDITSECTION{{ContentBlock|color=white|content={{!!}} These code snippets demonstrate how to set up an anti-aliasing filter that smoothes the image displayed on the screen...

2012-01-01T22:26:45Z

New page: __NOTOC__ __NOEDITSECTION__{{ContentBlock|color=white|content={{!!}} These code snippets demonstrate how to set up an anti-aliasing filter that smoothes the image displayed on the screen...

New page

__NOTOC__ __NOEDITSECTION__{{ContentBlock|color=white|content={{!!}}

These code snippets demonstrate how to set up an anti-aliasing filter that smoothes the image displayed on the screen. There are many ressources available for the exact math (e.g. [http://www.ngohq.com/images/articles/fxaa/FXAA_WhitePaper.pdf Nvidia]) behind FXAA and new variants are developed regularly.

It has been created by [http://www.horde3d.org/forums/viewtopic.php?f=4&t=1599 worstplayer].

== The Shader ==

{{CppSourceCode|
description= fxaa.shader|
code=
[[FX]]

// Samplers
sampler2D buf0 = sampler_state {
Address = Clamp;
Filter = None;
};

context FXAA {
VertexShader = compile GLSL VS_FSQUAD;
PixelShader = compile GLSL FS_FXAA;
}

[[VS_FSQUAD]]

uniform mat4 projMat;
attribute vec3 vertPos;
varying vec2 texCoords;

void main(void) {
texCoords = vertPos.xy;
gl_Position = projMat * vec4( vertPos, 1 );
}

[[FS_FXAA]]

uniform sampler2D buf0;
uniform vec2 frameBufSize;
varying vec2 texCoords;

void main( void ) {
//gl_FragColor.xyz = texture2D(buf0,texCoords).xyz;
//return;

float FXAA_SPAN_MAX = 8.0;
float FXAA_REDUCE_MUL = 1.0/8.0;
float FXAA_REDUCE_MIN = 1.0/128.0;

vec3 rgbNW=texture2D(buf0,texCoords+(vec2(-1.0,-1.0)/frameBufSize)).xyz;
vec3 rgbNE=texture2D(buf0,texCoords+(vec2(1.0,-1.0)/frameBufSize)).xyz;
vec3 rgbSW=texture2D(buf0,texCoords+(vec2(-1.0,1.0)/frameBufSize)).xyz;
vec3 rgbSE=texture2D(buf0,texCoords+(vec2(1.0,1.0)/frameBufSize)).xyz;
vec3 rgbM=texture2D(buf0,texCoords).xyz;

vec3 luma=vec3(0.299, 0.587, 0.114);
float lumaNW = dot(rgbNW, luma);
float lumaNE = dot(rgbNE, luma);
float lumaSW = dot(rgbSW, luma);
float lumaSE = dot(rgbSE, luma);
float lumaM = dot(rgbM, luma);

float lumaMin = min(lumaM, min(min(lumaNW, lumaNE), min(lumaSW, lumaSE)));
float lumaMax = max(lumaM, max(max(lumaNW, lumaNE), max(lumaSW, lumaSE)));

vec2 dir;
dir.x = -((lumaNW + lumaNE) - (lumaSW + lumaSE));
dir.y = ((lumaNW + lumaSW) - (lumaNE + lumaSE));

float dirReduce = max(
(lumaNW + lumaNE + lumaSW + lumaSE) * (0.25 * FXAA_REDUCE_MUL),
FXAA_REDUCE_MIN);

float rcpDirMin = 1.0/(min(abs(dir.x), abs(dir.y)) + dirReduce);

dir = min(vec2( FXAA_SPAN_MAX, FXAA_SPAN_MAX),
max(vec2(-FXAA_SPAN_MAX, -FXAA_SPAN_MAX),
dir * rcpDirMin)) / frameBufSize;

vec3 rgbA = (1.0/2.0) * (
texture2D(buf0, texCoords.xy + dir * (1.0/3.0 - 0.5)).xyz +
texture2D(buf0, texCoords.xy + dir * (2.0/3.0 - 0.5)).xyz);
vec3 rgbB = rgbA * (1.0/2.0) + (1.0/4.0) * (
texture2D(buf0, texCoords.xy + dir * (0.0/3.0 - 0.5)).xyz +
texture2D(buf0, texCoords.xy + dir * (3.0/3.0 - 0.5)).xyz);
float lumaB = dot(rgbB, luma);

if((lumaB < lumaMin) || (lumaB > lumaMax)){
gl_FragColor.xyz=rgbA;
}else{
gl_FragColor.xyz=rgbB;
}
}
}}

== The Material ==

{{CppSourceCode|
description= fxaa.material.xml|
code=
<Material>
<Shader source="fxaa.shader"/>
</Material>
}}

== The pipeline ==
Basically, the normal geometry is rendered to a new buffer instead of straight to the screen. Afterwards, the new FXAA shader works over this buffer and renders to screen.

{{CppSourceCode|
description= forward_plus_fxaa.pipeline.xml|
code=
<Pipeline>
<Setup>
<RenderTarget id="FINALIMAGE" depthBuf="true" numColBufs="1" format="RGBA16F" scale="1.0" maxSamples="0" />
</Setup>

<CommandQueue>
<Stage id="Ambient">
<SwitchTarget target="FINALIMAGE" />
<ClearTarget depthBuf="true" colBuf0="true" />

<DrawGeometry context="AMBIENT" class="~Translucent" />
</Stage>

<Stage id="Lighting">
<DoForwardLightLoop class="~Translucent" />
</Stage>

<Stage id="Translucent">
<DrawGeometry context="TRANSLUCENT" class="Translucent" />
</Stage>


<Stage id="FXAA">
<SwitchTarget target="" />
<BindBuffer sampler="buf0" sourceRT="FINALIMAGE" bufIndex="0" />
<DrawQuad material="fxaa.material.xml" context="FXAA" />
<UnbindBuffers />
</Stage>


<Stage id="Overlays">
<DrawOverlays context="OVERLAY" />
</Stage>
</CommandQueue>
</Pipeline>
}}

@@ Line 9: / Line 9: @@
 == The Shader ==
-{{CppSourceCode|
+<pre>
 [[FX]]
@@ Line 97: / Line 95: @@
+	}
+}
-}}
+</pre>
@@ Line 104: / Line 102: @@
 == The Material ==
-{{CppSourceCode|
+<pre>
 <Material>
 	<Shader source="fxaa.shader"/>
 </Material>
-}}
+</pre>
@@ Line 116: / Line 112: @@
 Basically, the normal geometry is rendered to a new buffer instead of straight to the screen. Afterwards, the new FXAA shader works over this buffer and renders to screen.
-{{CppSourceCode|
+<pre>
 <Pipeline>
 	<Setup>
@@ Line 155: / Line 149: @@
 	</CommandQueue>
 </Pipeline>
-}}
+</pre>
 }}

Shading Technique - FXAA - Revision history

Rand at 22:31, 1 January 2012

Rand at 22:28, 1 January 2012

Rand: New page: __NOTOC__ __NOEDITSECTION__{{ContentBlock|color=white|content={{!!}} These code snippets demonstrate how to set up an anti-aliasing filter that smoothes the image displayed on the screen...

Rand: New page: NOTOC NOEDITSECTION{{ContentBlock|color=white|content={{!!}} These code snippets demonstrate how to set up an anti-aliasing filter that smoothes the image displayed on the screen...