このバージョンの ssao をこのチュートリアルで実装しようとしています:
http://www.learnopengl.com/#!Advanced-Lighting/SSAO
レンダー テクスチャの最終的な結果は次のとおりです。
カメラを動かすと影がついてくる
カメラである種の行列乗算が欠けているようです。
コード
gBuffer頂点
#version 330 core
layout (location = 0) in vec3 vertexPosition;
layout (location = 1) in vec3 vertexNormal;
out vec3 position;
out vec3 normal;
uniform mat4 m;
uniform mat4 v;
uniform mat4 p;
uniform mat4 n;
void main()
{
vec4 viewPos = v * m * vec4(vertexPosition, 1.0f);
position = viewPos.xyz;
gl_Position = p * viewPos;
normal = vec3(n * vec4(vertexNormal, 0.0f));
}
gBuffer フラグメント
#version 330 core
layout (location = 0) out vec4 gPosition;
layout (location = 1) out vec3 gNormal;
layout (location = 2) out vec4 gColor;
in vec3 position;
in vec3 normal;
const float NEAR = 0.1f;
const float FAR = 50.0f;
float LinearizeDepth(float depth)
{
float z = depth * 2.0f - 1.0f;
return (2.0 * NEAR * FAR) / (FAR + NEAR - z * (FAR - NEAR));
}
void main()
{
gPosition.xyz = position;
gPosition.a = LinearizeDepth(gl_FragCoord.z);
gNormal = normalize(normal);
gColor.rgb = vec3(1.0f);
}
SSAO頂点
#version 330 core
layout (location = 0) in vec3 vertexPosition;
layout (location = 1) in vec2 texCoords;
out vec2 UV;
void main(){
gl_Position = vec4(vertexPosition, 1.0f);
UV = texCoords;
}
SSAOフラグメント
#version 330 core
out float FragColor;
in vec2 UV;
uniform sampler2D gPositionDepth;
uniform sampler2D gNormal;
uniform sampler2D texNoise;
uniform vec3 samples[32];
uniform mat4 projection;
// parameters (you'd probably want to use them as uniforms to more easily tweak the effect)
int kernelSize = 32;
float radius = 1.0;
// tile noise texture over screen based on screen dimensions divided by noise size
const vec2 noiseScale = vec2(1024.0f/4.0f, 1024.0f/4.0f);
void main()
{
// Get input for SSAO algorithm
vec3 fragPos = texture(gPositionDepth, UV).xyz;
vec3 normal = texture(gNormal, UV).rgb;
vec3 randomVec = texture(texNoise, UV * noiseScale).xyz;
// Create TBN change-of-basis matrix: from tangent-space to view-space
vec3 tangent = normalize(randomVec - normal * dot(randomVec, normal));
vec3 bitangent = cross(normal, tangent);
mat3 TBN = mat3(tangent, bitangent, normal);
// Iterate over the sample kernel and calculate occlusion factor
float occlusion = 0.0;
for(int i = 0; i < kernelSize; ++i)
{
// get sample position
vec3 sample = TBN * samples[i]; // From tangent to view-space
sample = fragPos + sample * radius;
// project sample position (to sample texture) (to get position on screen/texture)
vec4 offset = vec4(sample, 1.0);
offset = projection * offset; // from view to clip-space
offset.xyz /= offset.w; // perspective divide
offset.xyz = offset.xyz * 0.5 + 0.5; // transform to range 0.0 - 1.0
// get sample depth
float sampleDepth = -texture(gPositionDepth, offset.xy).w; // Get depth value of kernel sample
// range check & accumulate
float rangeCheck = smoothstep(0.0, 1.0, radius / abs(fragPos.z - sampleDepth ));
occlusion += (sampleDepth >= sample.z ? 1.0 : 0.0) * rangeCheck;
}
occlusion = 1.0 - (occlusion / kernelSize);
FragColor = occlusion;
}
私は周りを読んで、誰かが同様の問題を抱えていて、ビューマトリックスをssaoシェーダーに渡し、sampleDepthを掛けたのを見ました:
float sampleDepth = (viewMatrix * -texture(gPositionDepth, offset.xy)).w;
しかし、それは事態を悪化させるだけのようです。
影がカメラと共に移動するのを見ることができる上からの別のビューを次に示します。
カメラを特定の方法で配置すると、物事が整列します
