Hello!
I am fairly new to shaders, but I’ve been making progress. I have a simple set of shaders that I’m trying to implement, but I’m having a very weird outcome. My process is like so.
- Render Scene to RenderTarget
- Render Depth to RenderTarget using Shader.
- Set Depth & Random Normal textures to SSAO shader and render to RenderTarget using fullscreen quad (I have no idea if this is right, this is what I’ve observed that many others have been doing),
- Combine the Scene Render Target from Step 1 with the SSAO Render Target from Step 3 and Render Fullscreen Quad.
My output is a giant grey screen. In theory, are the high level steps in line with what one would need to do to apply SSAO to a scene? I’ve included various screenshots and files. I’m a bit lost and I’m thinking I may need to back off of trying to implement this until I understand this better. I’m open to trying anything at this point.
Scene RenderTarget
Depth Render Target
Step 2: Depth Shader
float4x4 WorldView;
float4x4 ITWorldView;
float4x4 WorldViewProjection;
float FarClip;
struct VS_INPUT
{
float4 Position: POSITION0;
float3 Normal : NORMAL;
};
struct VS_OUTPUT
{
float4 Position: POSITION0;
float3 Normal : TEXCOORD0;
float4 vPositionVS : TEXCOORD1;
};
VS_OUTPUT DepthVertexShaderFunction(VS_INPUT IN)
{
VS_OUTPUT Output;Output.Position = mul(IN.Position, WorldViewProjection);
Output.vPositionVS = mul(IN.Position, WorldView);
Output.Normal = mul(IN.Normal, ITWorldView);return Output;
}
float4 DepthPixelShaderFunction(VS_OUTPUT IN) : COLOR0
{
float depth = IN.vPositionVS.z / FarClip;
IN.Normal = normalize(IN.Normal);
return float4(IN.Normal.x, IN.Normal.y, IN.Normal.z, depth);
}
technique Depth
{
pass Pass1
{
VertexShader = compile vs_4_0 DepthVertexShaderFunction(); PixelShader = compile ps_4_0 DepthPixelShaderFunction(); }}
Step 3: SSAO Shader
float sampleRadius;
float distanceScale;
float4x4 Projection;
float3 cornerFustrum;
struct VS_OUTPUT
{
float4 pos : POSITION;
float2 TexCoord : TEXCOORD0;
float3 viewDirection : TEXCOORD1;
};
VS_OUTPUT VS(
float4 Position : POSITION, float2 TexCoord : TEXCOORD0)
{
VS_OUTPUT Out = (VS_OUTPUT)0;
Out.pos = Position; Position.xy = sign(Position.xy); Out.TexCoord = (float2(Position.x, -Position.y) + float2( 1.0f, 1.0f ) ) * 0.5f; float3 corner = float3(-cornerFustrum.x * Position.x, cornerFustrum.y * Position.y, cornerFustrum.z);Out.viewDirection = corner;
return Out;}
texture depthTexture;
texture randomTexture;
sampler2D depthSampler = sampler_state
{
Texture = ;
ADDRESSU = CLAMP;
ADDRESSV = CLAMP;
MAGFILTER = LINEAR;
MINFILTER = LINEAR;
};
sampler2D RandNormal = sampler_state
{
Texture = ;
ADDRESSU = WRAP;
ADDRESSV = WRAP;
MAGFILTER = LINEAR;
MINFILTER = LINEAR;
};
float4 PS(VS_OUTPUT IN) : COLOR0
{
float4 samples[16] =
{
float4(0.355512, -0.709318, -0.102371, 0.0 ),
float4(0.534186, 0.71511, -0.115167, 0.0 ),
float4(-0.87866, 0.157139, -0.115167, 0.0 ),
float4(0.140679, -0.475516, -0.0639818, 0.0 ),
float4(-0.0796121, 0.158842, -0.677075, 0.0 ),
float4(-0.0759516, -0.101676, -0.483625, 0.0 ),
float4(0.12493, -0.0223423, -0.483625, 0.0 ),
float4(-0.0720074, 0.243395, -0.967251, 0.0 ),
float4(-0.207641, 0.414286, 0.187755, 0.0 ),
float4(-0.277332, -0.371262, 0.187755, 0.0 ),
float4(0.63864, -0.114214, 0.262857, 0.0 ),
float4(-0.184051, 0.622119, 0.262857, 0.0 ),
float4(0.110007, -0.219486, 0.435574, 0.0 ),
float4(0.235085, 0.314707, 0.696918, 0.0 ),
float4(-0.290012, 0.0518654, 0.522688, 0.0 ),
float4(0.0975089, -0.329594, 0.609803, 0.0 )
};IN.TexCoord.x += 1.0/1600.0;
IN.TexCoord.y += 1.0/1200.0;
normalize (IN.viewDirection);
float depth = tex2D(depthSampler, IN.TexCoord).a;
float3 se = depth * IN.viewDirection;float3 randNormal = tex2D( RandNormal, IN.TexCoord * 200.0 ).rgb;
float3 normal = tex2D(depthSampler, IN.TexCoord).rgb;
float finalColor = 0.0f;for (int i = 0; i < 16; i++)
{
float3 ray = reflect(samples[i].xyz,randNormal) * sampleRadius;//if (dot(ray, normal) < 0) // ray += normal * sampleRadius; float4 sample = float4(se + ray, 1.0f); float4 ss = mul(sample, Projection);
float2 sampleTexCoord = 0.5f * ss.xy/ss.w + float2(0.5f, 0.5f); sampleTexCoord.x += 1.0/1600.0; sampleTexCoord.y += 1.0/1200.0; float sampleDepth = tex2D(depthSampler, sampleTexCoord).a; if (sampleDepth == 1.0) { finalColor ++; } else { float occlusion = distanceScale* max(sampleDepth - depth, 0.0f); finalColor += 1.0f / (1.0f + occlusion * occlusion * 0.1); }}
return float4(finalColor/16, finalColor/16, finalColor/16, 1.0f);
}
technique SSAO
{
pass P0
{
VertexShader = compile vs_4_0 VS();
PixelShader = compile ps_4_0 PS();
}
}
Step 4: SSAO Combine
//sampler baseSampler : register(s0);
texture SSAOTex;
sampler2D SSAOSampler = sampler_state
{
Texture = ;
ADDRESSU = CLAMP;
ADDRESSV = CLAMP;
MAGFILTER = LINEAR;
MINFILTER = LINEAR;
};
texture SceneTexture;
sampler2D baseSampler = sampler_state
{
Texture = ;
ADDRESSU = CLAMP;
ADDRESSV = CLAMP;
MAGFILTER = LINEAR;
MINFILTER = LINEAR;
};
float4 PixelShaderFunction(float2 TexCoord :TEXCOORD0) : COLOR0
{
TexCoord.x += 1.0/1600.0;
TexCoord.y += 1.0/1200.0;
return tex2D( SSAOSampler, TexCoord ).r * (tex2D(baseSampler,TexCoord) );
}
technique Merge
{
pass Pass1
{
PixelShader = compile ps_4_0 PixelShaderFunction();
}
}
**
?