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Author: Ka1serM

src/lib/data/tasks.json

@@ -155,27 +155,33 @@ uniform vec3 cameraDirection;
 uniform sampler3D volumeTexture;
 uniform ivec2 iResolution;
 
-const float stepSize = 0.001;
+const float stepSize = 0.0015;
 const int   maxSteps = 1024;
 const vec3  lightDir = normalize(vec3(1.0, 1.0, 0.0));
 const float orthoScale = 0.5;
 
 vec3 ComputeGradient(vec3 UVW) {
     vec3 H = 1.0 / vec3(textureSize(volumeTexture, 0)); // Texelgröße
 
-    float Fx1 = texture(volumeTexture, clamp(UVW + vec3(H.x, 0.0, 0.0), 0.0, 1.0)).r; // +x Probe
-    float Fx2 = texture(volumeTexture, clamp(UVW - vec3(H.x, 0.0, 0.0), 0.0, 1.0)).r; // -x Probe
+    float Fx1 = texture(volumeTexture, clamp(UVW + vec3(H.x, 0.0, 0.0), 0.0, 1.0)).r;
+    float Fx2 = texture(volumeTexture, clamp(UVW - vec3(H.x, 0.0, 0.0), 0.0, 1.0)).r;
 
-    float Fy1 = texture(volumeTexture, clamp(UVW + vec3(0.0, H.y, 0.0), 0.0, 1.0)).r; // +y Probe
-    float Fy2 = texture(volumeTexture, clamp(UVW - vec3(0.0, H.y, 0.0), 0.0, 1.0)).r; // -y Probe
+    float Fy1 = texture(volumeTexture, clamp(UVW + vec3(0.0, H.y, 0.0), 0.0, 1.0)).r;
+    float Fy2 = texture(volumeTexture, clamp(UVW - vec3(0.0, H.y, 0.0), 0.0, 1.0)).r;
 
-    float Fz1 = texture(volumeTexture, clamp(UVW + vec3(0.0, 0.0, H.z), 0.0, 1.0)).r; // +z Probe
-    float Fz2 = texture(volumeTexture, clamp(UVW - vec3(0.0, 0.0, H.z), 0.0, 1.0)).r; // -z Probe
+    float Fz1 = texture(volumeTexture, clamp(UVW + vec3(0.0, 0.0, H.z), 0.0, 1.0)).r;
+    float Fz2 = texture(volumeTexture, clamp(UVW - vec3(0.0, 0.0, H.z), 0.0, 1.0)).r;
 
-    return normalize(-vec3(Fx1 - Fx2, Fy1 - Fy2, Fz1 - Fz2)); // Zentraldiff, Negation
+    vec3 grad = vec3(
+        (Fx1 - Fx2) / (2.0 * H.x),
+        (Fy1 - Fy2) / (2.0 * H.y),
+        (Fz1 - Fz2) / (2.0 * H.z)
+    );
+    return grad; // nthält auch die stärke über die Länge
 }
 
-vec4 TransferFunction(float F, float gradientMagnitude) {
+vec4 TransferFunction(float F, float gradientMagnitude)
+{
     const float huAir    = -750.0;
     const float huTissue =   50.0;
     const float huBone   =  700.0;
@@ -185,36 +191,41 @@ vec4 TransferFunction(float F, float gradientMagnitude) {
     const float alphaBone   = 1.0;
 
     const vec3 colorAir    = vec3(0.0);
-    const vec3 colorTissue = vec3(0.9, 0.7, 0.6);
-    const vec3 colorBone   = vec3(1.0, 1.0, 0.95);
-
-    float alpha = 0.0;
-    vec3 Color = colorAir;
-
-    if (F >= huAir && F <= huTissue) {
-        float T = (F - huAir) / (huTissue - huAir); // Air >Tissue Mix
-        alpha = mix(alphaAir, alphaTissue, T);
-        Color = mix(colorAir, colorTissue, T);
-    } else if (F >= huTissue && F <= huBone) {
-        float T = (F - huTissue) / (huBone - huTissue); // Tissue > Bone Mix
-        alpha = mix(alphaTissue, alphaBone, T);
-        Color = mix(colorTissue, colorBone, T);
-    } else if (F > huBone) {
-        alpha = alphaBone; // Bone+
-        Color = colorBone;
+    const vec3 colorTissue = vec3(0.929, 0.675, 0.522);
+    const vec3 colorBone   = vec3(0.949, 0.898, 0.643);
+
+    float alpha;
+    vec3  color;
+    if (F <= huAir) {
+        alpha = alphaAir;
+        color = colorAir;
+    } 
+    else if (F < huTissue) {
+        float t = (F - huAir) / (huTissue - huAir);
+        alpha = mix(alphaAir, alphaTissue, t);
+        color = mix(colorAir, colorTissue, t);
+    } 
+    else if (F < huBone) {
+        float t = (F - huTissue) / (huBone - huTissue);
+        alpha = mix(alphaTissue, alphaBone, t);
+        color = mix(colorTissue, colorBone, t);
+    } 
+    else {
+        alpha = alphaBone;
+        color = colorBone;
     }
 
-    // hermit Interpolation zwischen 0 und 1, lower bound, upper bound, source Wert
-    alpha *= smoothstep(0.05, 0.2, gradientMagnitude); // Übergang mit Gradient verstärken
+    // Gewichtung mit Gradient um die Kanten zwischen Oberflächen deutlich zu machen
+    alpha *= 1.0 - exp(-5.0 * clamp(gradientMagnitude / 8.0, 0.0, 1.0)); // 0 -> flat region, 1 -> sharp edge
 
-    return vec4(Color, alpha);
+    return vec4(color, alpha);
 }
 
 vec3 PhongShade(vec3 N, vec3 BaseColor, vec3 ViewDir, vec3 lightDir) {
-    const vec3 Ka = vec3(0.5); // Ambient
-    const vec3 Kd = vec3(0.5); // Diffus
-    const vec3 Ks = vec3(1.0); // Spekular
-    const float NExp = 20.0; // Rauheit
+    const vec3 Ka = vec3(0.01); // Ambient
+    const vec3 Kd = vec3(1.0); // Diffus
+    const vec3 Ks = vec3(0.3); // Spekular
+    const float NExp = 120.0; // Rauheit
 
     vec3 H = normalize(ViewDir + lightDir); // Halfvector
     float Diff = max(dot(N, lightDir), 0.0); // Diffus
@@ -243,7 +254,7 @@ vec4 SampleVolume(vec3 UVW, vec3 rayDir) {
     float gradientMagnitude = length(Grad);
 
     vec4 Mat = TransferFunction(F, gradientMagnitude); // Materialdaten
-    vec3 Shaded = PhongShade(normalize(Grad), Mat.rgb, normalize(-rayDir), lightDir); // Beleuchtung
+    vec3 Shaded = PhongShade(normalize(-Grad), Mat.rgb, normalize(-rayDir), lightDir); // Beleuchtung
 
     return vec4(Shaded, Mat.a); // Farbe + alpha
 }
@@ -252,7 +263,7 @@ void main() {
     vec3 rayOrigin, rayDir;
     GenerateRay(rayOrigin, rayDir); // Strahl erzeugen
 
-    float TNear = 0.01; // Start
+    float TNear = 0.001; // Start
     float TFar = 2.0;   // Ende
 
     vec3 ColorAccum = vec3(0.0); // Farbspeicher