random fixes of raymarching shaders

Author: tiye

vr-dive/Demos/Floreus/FloreusShaders.metal

@@ -38,9 +38,9 @@ struct FloreusVertexOut {
 
 static constant float3 FL_BOX_HALF = float3(1.0f);
 static constant float FL_TRACE_EPSILON = 0.0015f;
-static constant int FL_STEPS = 100;
+static constant int FL_STEPS = 140;
 static constant int FL_INNER_STEPS = 5;
-static constant float FL_SCENE_SCALE = 8.0f;
+static constant float FL_SCENE_SCALE = 2.4f;
 
 vertex FloreusVertexOut floreusVertex(
     ushort amplificationID [[amplification_id]],
@@ -140,7 +140,7 @@ fragment float4 floreusFragment(
         accum += float4(3.0f, 2.0f, 1.0f, 1.0f) * 20.0f * d / max(s, 1.0e-4f);
     }
 
-    float4 color = tanh(accum / 1.0e7f);
+    float4 color = tanh(accum / 3.5e6f);
     float2 q = flFaceUV(hit);
     float vignette = 1.0f - 0.35f * dot(q * 2.0f - 1.0f, q * 2.0f - 1.0f);
     color.rgb *= vignette;

vr-dive/Demos/Fractal49Gaz/Fractal49GazShaders.metal

@@ -41,6 +41,10 @@ static float3 hue(float h) {
     return cos(h * 6.3f + float3(0.0f, 23.0f, 21.0f)) * 0.5f + 0.5f;
 }
 
+static float3 fgTonemap(float3 color) {
+    return color / (1.0f + color);
+}
+
 static float3 rotateAroundAxis(float3 p, float3 axis, float angle) {
     float c = cos(angle);
     float s = sin(angle);
@@ -107,8 +111,8 @@ static FractalAccum traceFractal(float3 ro, float3 rd, float time) {
         lastError = length(cross(p, FG_EQ)) / s - 5.0e-4f;
         float3 tint = mix(float3(1.0f), hue(log(max(s, 1.0e-4f)) * 0.3f), 0.8f);
         float falloff = exp(-12.0f * iteration * iteration * max(lastError, 0.0f));
-        accum.color += 0.1f * tint * falloff;
-        accum.glow += 0.015f / (0.0005f + lastError * lastError);
+        accum.color += 0.03f * tint * falloff;
+        accum.glow += min(0.04f, 0.0016f / (0.002f + lastError * lastError));
 
         g += lastError;
         if (g > 18.0f) {
@@ -176,18 +180,18 @@ fragment float4 fractal49GazFragment(
         float3(0.03f, 0.02f, 0.06f),
         float3(0.24f, 0.08f, 0.32f),
         horizon);
-    background += hue(uniforms.time * 0.08f + swirl * 0.25f) * (0.08f + 0.22f * facing);
-    background += float3(0.14f, 0.28f, 0.1f) * swirl * 0.3f;
+    background += hue(uniforms.time * 0.08f + swirl * 0.25f) * (0.025f + 0.08f * facing);
+    background += float3(0.14f, 0.28f, 0.1f) * swirl * 0.08f;
 
     float2 faceUV = fgFaceUV(surfacePos) * 2.0f - 1.0f;
     float vignette = 1.0f - 0.16f * dot(faceUV, faceUV);
 
-    float glow = accum.glow * 0.007f;
-    float3 color = background * 0.75f + accum.color;
+    float glow = min(accum.glow, 6.0f) * 0.02f;
+    float3 color = background * 0.22f + accum.color;
     color += glow * float3(0.45f, 0.82f, 0.52f);
     color *= vignette;
 
-    color = clamp(color, 0.0f, 1.0f);
-    color = pow(color, float3(0.92f));
+    color = fgTonemap(max(color, 0.0f));
+    color = pow(color, float3(0.96f));
     return float4(color, 1.0f);
 }

vr-dive/Demos/Fractal77Gaz/Fractal77GazShaders.metal

@@ -39,6 +39,10 @@ static float3 hue77(float h) {
     return cos(h * 6.3f + float3(0.0f, 23.0f, 21.0f)) * 0.5f + 0.5f;
 }
 
+static float3 f77Tonemap(float3 color) {
+    return color / (1.0f + color);
+}
+
 static float3 rotateAroundAxis77(float3 p, float3 axis, float angle) {
     float c = cos(angle);
     float s = sin(angle);
@@ -98,16 +102,16 @@ static Fractal77Accum traceFractal77(float3 ro, float3 rd, float time) {
         e = length(p.xz) / max(s, 1.0e-4f);
         float3 tint = mix(float3(0.09f, 0.12f, 0.18f), hue77(log(max(s, 1.0e-4f))), 0.7f);
         float falloff = exp(-iteration * iteration * e);
-        accum.color += tint * 0.08f * falloff;
-        accum.energy += 0.018f / (0.002f + e * e * 12.0f);
+        accum.color += tint * 0.04f * falloff;
+        accum.energy += min(0.03f, 0.008f / (0.01f + e * e * 14.0f));
 
         g += e;
         if (g > 18.0f) {
             break;
         }
     }
 
-    accum.color = pow(clamp(accum.color, 0.0f, 3.0f), float3(5.0f));
+    accum.color = pow(f77Tonemap(clamp(accum.color, 0.0f, 4.0f)), float3(3.2f));
     return accum;
 }
 
@@ -165,15 +169,15 @@ fragment float4 fractal77GazFragment(
         float3(0.015f, 0.02f, 0.04f),
         float3(0.16f, 0.08f, 0.23f),
         horizon);
-    background += hue77(uniforms.time * 0.1f + axisFacing * 0.3f) * (0.05f + 0.18f * axisFacing);
-    background += float3(0.28f, 0.34f, 0.5f) * accum.energy * 0.03f;
+    background += hue77(uniforms.time * 0.1f + axisFacing * 0.3f) * (0.025f + 0.08f * axisFacing);
+    background += float3(0.28f, 0.34f, 0.5f) * accum.energy * 0.012f;
 
     float2 faceUV = f77FaceUV(surfacePos) * 2.0f - 1.0f;
     float vignette = 1.0f - 0.16f * dot(faceUV, faceUV);
 
-    float3 color = background * 0.8f + accum.color;
-    color += accum.energy * float3(0.55f, 0.78f, 1.05f) * 0.01f;
+    float3 color = background * 0.35f + accum.color;
+    color += accum.energy * float3(0.55f, 0.78f, 1.05f) * 0.004f;
     color *= vignette;
-    color = clamp(color, 0.0f, 1.0f);
+    color = f77Tonemap(max(color, 0.0f));
     return float4(color, 1.0f);
 }

vr-dive/Demos/SaturdayWeirdness/SaturdayWeirdnessShaders.metal

@@ -71,12 +71,9 @@ static float2 swRotate2D(float2 p, float a) {
     return float2(c * p.x - s * p.y, s * p.x + c * p.y);
 }
 
-static float3 swFold(float3 p, float time) {
-    p.xz = swRotate2D(p.xz, time * 0.22f + p.y * 0.08f);
-    p.xy = swRotate2D(p.xy, time * -0.17f + sin(p.z * 0.5f) * 0.6f);
-    p = abs(p) - float3(1.15f, 0.85f, 1.15f);
-    p.yz = swRotate2D(p.yz, 0.75f + sin(time * 0.33f) * 0.4f);
-    return p;
+static float swRoundBox(float3 p, float3 b, float r) {
+    float3 q = abs(p) - b;
+    return length(max(q, 0.0f)) + min(max(q.x, max(q.y, q.z)), 0.0f) - r;
 }
 
 static float swGyroid(float3 p) {
@@ -114,23 +111,18 @@ static float2 swFaceUV(float3 p) {
 static SWHit swMap(float3 p, float time) {
     SWHit hit;
 
-    float3 q = p * 2.35f;
-    q = swFold(q, time);
+    float3 q = p * 1.55f;
+    q.xz = swRotate2D(q.xz, time * 0.2f);
+    q.yz = swRotate2D(q.yz, 0.65f + sin(time * 0.33f) * 0.25f);
 
-    float gyroid = swGyroid(q * 1.55f + time * 0.7f);
-    float bandsA = sin(q.x * 6.0f + sin(q.z * 2.0f - time * 1.6f) * 1.6f);
-    float bandsB = sin(q.y * 7.0f - cos(q.x * 2.6f + time * 1.2f) * 1.4f);
-    float bandsC = sin(q.z * 6.8f + q.x * 1.8f - time * 0.9f);
-    float ribbons = abs(bandsA + bandsB * 0.75f + bandsC * 0.6f + gyroid * 0.55f) - 0.24f;
+    float core = swRoundBox(q, float3(0.7f), 0.28f);
+    float gyroid = swGyroid(q * 3.1f + time * 0.7f);
+    float grooves = sin(q.x * 7.0f) + sin(q.y * 7.6f) + sin(q.z * 6.8f);
+    float detail = (abs(gyroid) - 0.24f) * 0.045f + grooves * 0.012f;
+    float sdf = core + detail;
 
-    float shellRadius = length(q.xz) - (1.35f + 0.22f * sin(q.y * 3.0f - time * 1.1f));
-    float shell = abs(shellRadius) - (0.11f + 0.04f * sin(q.y * 8.0f + time * 1.9f));
-
-    float knots = length(float2(abs(gyroid), ribbons)) - 0.2f;
-    float sdf = min(ribbons * 0.16f, min(shell * 0.24f, knots * 0.22f));
-
-    float edgeSignal = abs(ribbons) + abs(shell) * 0.35f + abs(gyroid) * 0.25f;
-    float colorPhase = 0.16f * q.y + 0.08f * q.z + sin(time * 0.45f) * 0.2f;
+    float edgeSignal = abs(detail) + abs(gyroid) * 0.08f;
+    float colorPhase = 0.14f * q.y + 0.1f * q.z + sin(time * 0.45f) * 0.2f;
 
     hit.distance = 0.0f;
     hit.sdf = sdf;
@@ -179,7 +171,7 @@ fragment float4 saturdayWeirdnessFragment(
     }
 
     float tStart = insideBox ? 0.0f : max(tBox.x, 0.0f);
-    float3 ro = (eye + rd * (tStart + SW_HIT_EPSILON)) * 3.5f;
+    float3 ro = (eye + rd * (tStart + SW_HIT_EPSILON)) * 2.0f;
 
     float travel = 0.0f;
     SWHit state = swMap(ro, uniforms.time);
@@ -189,7 +181,7 @@ fragment float4 saturdayWeirdnessFragment(
         if (abs(state.sdf) < SW_HIT_EPSILON || travel > SW_MAX_DIST) {
             break;
         }
-        travel += clamp(abs(state.sdf), 0.01f, 0.18f);
+        travel += clamp(abs(state.sdf), 0.008f, 0.14f);
     }
 
     if (travel > SW_MAX_DIST || abs(state.sdf) >= 0.02f) {

vr-dive/Demos/SineBud/SineBudShaders.metal

@@ -40,7 +40,7 @@ static constant float3 SB_BOX_HALF = float3(1.0f);
 static constant float SB_TRACE_EPSILON = 0.0015f;
 static constant int SB_STEPS = 200;
 static constant float SB_MAX_DIST = 100.0f;
-static constant float SB_SCENE_SCALE = 18.0f;
+static constant float SB_SCENE_SCALE = 8.0f;
 
 vertex SineBudVertexOut sineBudVertex(
     ushort amplificationID [[amplification_id]],
@@ -144,7 +144,8 @@ fragment float4 sineBudFragment(
     float d = 0.0f;
     float s = 1.0f;
     float3 k = float3(0.0f);
-    float3 c = float3(0.0f, 1.0f, 2.0f) * length(rd.xy);
+    float3 c = float3(0.0f);
+    bool hitBud = false;
 
     for (int step = 0; step < SB_STEPS; ++step) {
         float3 p = ro + rd * d;
@@ -167,13 +168,16 @@ fragment float4 sineBudFragment(
 
         s = min(s, min(k.z, min(k.x, k.y)));
         if (s < 0.001f || d > SB_MAX_DIST) {
+            hitBud = s < 0.001f;
             break;
         }
         d += s * 0.3f;
     }
 
-    c += max(cos(d * SB_PI * 2.0f) - s * sqrt(max(d, 0.0f)) - k, 0.0f);
-    float3 color = c + c.brg + c * c;
+    if (hitBud) {
+        c += max(cos(d * SB_PI * 2.0f) - s * sqrt(max(d, 0.0f)) - k, 0.0f);
+    }
+    float3 color = hitBud ? (c + c.brg + c * c) : float3(0.0f);
 
     float2 q = sbFaceUV(hit);
     float vignette = 1.0f - 0.35f * dot(q * 2.0f - 1.0f, q * 2.0f - 1.0f);