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-rw-r--r--2ner.cginc19
-rw-r--r--2ner.shader32
-rw-r--r--features.cginc9
-rw-r--r--fog.cginc136
-rw-r--r--globals.cginc18
5 files changed, 113 insertions, 101 deletions
diff --git a/2ner.cginc b/2ner.cginc
index 3bec555..e6d2433 100644
--- a/2ner.cginc
+++ b/2ner.cginc
@@ -230,23 +230,20 @@ float4 frag(v2f i, uint facing : SV_IsFrontFace
FogParams fog_params = {
_Raymarched_Fog_Color.rgb,
_Raymarched_Fog_Steps,
- _Raymarched_Fog_Density,
_Raymarched_Fog_Y_Cutoff,
_Raymarched_Fog_Dithering_Noise,
_Raymarched_Fog_Dithering_Noise_TexelSize,
_Raymarched_Fog_Density_Noise,
_Raymarched_Fog_Density_Noise_Scale,
_Raymarched_Fog_Velocity.xyz,
- #if defined(_RAYMARCHED_FOG_DENSITY_EXPONENT)
- _Raymarched_Fog_Density_Exponent,
- #endif
- #if defined(_RAYMARCHED_FOG_HEIGHT_DENSITY)
- _Raymarched_Fog_Height_Density_Start,
- _Raymarched_Fog_Height_Density_Half_Life,
- #endif
- #if defined(_CUSTOM30_FOG_HEIGHT_DENSITY_MINIMUM)
- _Custom30_Fog_Height_Density_Minimum,
- #endif
+ _Raymarched_Fog_Mean_Free_Path,
+ _Raymarched_Fog_Albedo,
+ _Raymarched_Fog_G,
+ _Raymarched_Fog_Height_Scale,
+ _Raymarched_Fog_Height_Offset,
+ _Raymarched_Fog_Turbulence,
+ _Raymarched_Fog_Step_Size,
+ _Raymarched_Fog_Step_Growth,
#if defined(_RAYMARCHED_FOG_EMITTER_TEXTURE)
_Raymarched_Fog_Emitter_Texture,
_Raymarched_Fog_Emitter_Texture_TexelSize,
diff --git a/2ner.shader b/2ner.shader
index 3dffe34..3472187 100644
--- a/2ner.shader
+++ b/2ner.shader
@@ -830,35 +830,19 @@ Shader "yum_food/2ner"
[ThryToggle(_RAYMARCHED_FOG)] _Raymarched_Fog_Enabled("Enable", Float) = 0
_Raymarched_Fog_Steps("Steps", Range(1, 32)) = 32
_Raymarched_Fog_Color("Color", Color) = (0.3, 0.3, 0.3, 1)
- _Raymarched_Fog_Density("Density", Float) = 1.0
_Raymarched_Fog_Dithering_Noise("Dithering noise", 2D) = "black" {}
_Raymarched_Fog_Density_Noise("Density noise", 3D) = "black" {}
_Raymarched_Fog_Density_Noise_Scale("Density noise scale", Vector) = (1, 1, 1, 0)
_Raymarched_Fog_Y_Cutoff("Y cutoff", Float) = -1000
_Raymarched_Fog_Velocity("Velocity", Vector) = (1, -.2, 0, 0)
-
- //ifex _Raymarched_Fog_Density_Exponent_Enabled==0
- [HideInInspector] m_start_Raymarched_Fog_Density_Exponent("Density exponent", Float) = 0
- [ThryToggle(_RAYMARCHED_FOG_DENSITY_EXPONENT)] _Raymarched_Fog_Density_Exponent_Enabled("Enable", Float) = 0
- _Raymarched_Fog_Density_Exponent("Exponent", Float) = 1
- [HideInInspector] m_end_Raymarched_Fog_Density_Exponent("Density exponent", Float) = 0
- //endex
-
- //ifex _Raymarched_Fog_Height_Density_Enabled==0
- [HideInInspector] m_start_Raymarched_Fog_Height_Density("Height density", Float) = 0
- [ThryToggle(_RAYMARCHED_FOG_HEIGHT_DENSITY)] _Raymarched_Fog_Height_Density_Enabled("Enable", Float) = 0
- _Raymarched_Fog_Height_Density_Start("Start elevation", Float) = 0
- _Raymarched_Fog_Height_Density_Half_Life("Half life", Float) = 1
-
- //ifex _Custom30_Fog_Height_Density_Minimum_Enabled==0
- [HideInInspector] m_start_Custom30_Fog_Height_Density_Minimum("Minimum", Float) = 0
- [ThryToggle(_CUSTOM30_FOG_HEIGHT_DENSITY_MINIMUM)] _Custom30_Fog_Height_Density_Minimum_Enabled("Enable", Float) = 0
- _Custom30_Fog_Height_Density_Minimum("Minimum factor", Float) = 0
- [HideInInspector] m_end_Custom30_Fog_Height_Density_Minimum("Minimum", Float) = 0
- //endex
- [HideInInspector] m_end_Raymarched_Fog_Height_Density("Height density", Float) = 0
- //endex
-
+ _Raymarched_Fog_Mean_Free_Path("Mean free path", Float) = 1
+ _Raymarched_Fog_Albedo("Albedo", Float) = 1
+ _Raymarched_Fog_G("G", Float) = 1
+ _Raymarched_Fog_Height_Scale("Height scale", Float) = 10
+ _Raymarched_Fog_Height_Offset("Height offset", Float) = 0
+ _Raymarched_Fog_Turbulence("Turbulence", Float) = 1
+ _Raymarched_Fog_Step_Size("Step size", Float) = 0.8
+ _Raymarched_Fog_Step_Growth("Step growth", Float) = 1.25
//ifex _Raymarched_Fog_Emitter_Texture_Enabled==0
[HideInInspector] m_start_Raymarched_Fog_Emitter_Texture("Emitter texture", Float) = 0
[ThryToggle(_RAYMARCHED_FOG_EMITTER_TEXTURE)] _Raymarched_Fog_Emitter_Texture_Enabled("Enable", Float) = 0
diff --git a/features.cginc b/features.cginc
index 589e4cf..b46c97e 100644
--- a/features.cginc
+++ b/features.cginc
@@ -317,15 +317,6 @@
#pragma shader_feature_local _RAYMARCHED_FOG
//endex
-//ifex _Raymarched_Fog_Height_Density_Enabled==0
-#pragma shader_feature_local _RAYMARCHED_FOG_HEIGHT_DENSITY
-#pragma shader_feature_local _CUSTOM30_FOG_HEIGHT_DENSITY_MINIMUM
-//endex
-
-//ifex _Raymarched_Fog_Density_Exponent_Enabled==0
-#pragma shader_feature_local _RAYMARCHED_FOG_DENSITY_EXPONENT
-//endex
-
//ifex _Raymarched_Fog_Emitter_Texture_Enabled==0
#pragma shader_feature_local _RAYMARCHED_FOG_EMITTER_TEXTURE
//endex
diff --git a/fog.cginc b/fog.cginc
index 6e471e9..6057f36 100644
--- a/fog.cginc
+++ b/fog.cginc
@@ -5,29 +5,28 @@
#include "cnlohr.cginc"
#include "interpolators.cginc"
#include "globals.cginc"
+#include "LightVolumes.cginc"
#if defined(_RAYMARCHED_FOG)
struct FogParams {
float3 color;
float steps;
- float density;
float y_cutoff;
texture2D dithering_noise;
float4 dithering_noise_texelsize;
texture3D density_noise;
float4 density_noise_scale;
float3 velocity;
-#if defined(_RAYMARCHED_FOG_DENSITY_EXPONENT)
- float density_exponent;
-#endif
-#if defined(_RAYMARCHED_FOG_HEIGHT_DENSITY)
- float height_density_start;
- float height_density_half_life;
-#endif
-#if defined(_CUSTOM30_FOG_HEIGHT_DENSITY_MINIMUM)
- float height_density_minimum;
-#endif
+ // Physical description of the medium (all in metres or unit-less)
+ float mean_free_path; // ⟨s⟩ = 1 / σ_t
+ float albedo; // ω = σ_s / σ_t (0 … 1)
+ float g; // Henyey-Greenstein anisotropy (−1 … 1)
+ float height_scale; // H where ρ(y)=ρ₀·exp(−y/H)
+ float height_offset;
+ float turbulence; // Strength of noise modulation (0 … 1)
+ float step_size;
+ float step_growth;
#if defined(_RAYMARCHED_FOG_EMITTER_TEXTURE)
texture2D emitter_texture;
float4 emitter_texture_texelsize;
@@ -66,6 +65,16 @@ float3 getEmitterData(FogParams p, float3 pp)
}
#endif
+// ---------------------------------------------------------------------------
+// Henyey–Greenstein phase function
+static const float INV_FOUR_PI = 0.079577471545947667884f; // 1/(4π)
+
+inline float PhaseHG(float cosTheta, float g)
+{
+ float g2 = g * g;
+ return INV_FOUR_PI * (1.0 - g2) / pow(1.0 + g2 - 2.0 * g * cosTheta, 1.5);
+}
+
struct FogResult {
float4 color;
float depth;
@@ -96,7 +105,6 @@ FogResult raymarched_fog(v2f i, FogParams p)
}
}
linearZ = min(linearZ, distance_to_y);
- linearZ = min(linearZ, 1200);
linearZ -= ro_epsilon;
float dither = p.dithering_noise.SampleLevel(point_repeat_s,
@@ -104,54 +112,88 @@ FogResult raymarched_fog(v2f i, FogParams p)
const float frame = ((float) AudioLinkData(ALPASS_GENERALVU + int2(1, 0)).x);
dither = frac(dither + PHI * frame);
- ro += rd * dither;
- linearZ -= dither;
- float step_size = linearZ / p.steps;
+ // Exponential stepping parameters
+ float step_size = p.step_size;
+ float step_growth = p.step_growth;
+
float3 pp = ro;
- float4 color = 0;
+ float max_dist = linearZ;
+
+ float T = 1; // Transmittance
+ float3 L = 0; // Accumulated radiance
+ float traveled = 0;
+
[loop]
- for (uint ii = 0; ii < p.steps; ++ii) {
- pp += step_size * rd;
-
+ for (uint ii = 0; ii < p.steps && traveled < max_dist; ++ii)
+ {
+ // Clamp step size to avoid missing dense features
+ float current_step = min(step_size, 2.0 * p.mean_free_path);
+
+ // Apply dithering to this step
+ float dithered_step = current_step * (1.0 - dither + dither * 2.0);
+
+ // Advance position
+ pp += dithered_step * rd;
+ traveled += dithered_step;
+
+ // --- Density ----------------------------------------------------------
float3 noise_coord = (pp + _Time[0] * p.velocity) * p.density_noise_scale.xyz;
+ float noise_sample = p.density_noise.SampleLevel(bilinear_repeat_s, noise_coord, 0).r;
+ float noise_factor = lerp(1.0 - 0.5 * p.turbulence, 1.0 + 0.5 * p.turbulence, noise_sample);
- float cur_d = p.density_noise.SampleLevel(bilinear_repeat_s,
- noise_coord, 0);
+ float height_factor = exp(-max(pp.y - p.height_offset, 0.0) / p.height_scale);
-#if defined(_RAYMARCHED_FOG_DENSITY_EXPONENT)
- cur_d = pow(cur_d, p.density_exponent);
-#endif
+ float sigma_t = noise_factor * height_factor / max(p.mean_free_path, 1e-4);
+ float sigma_s = sigma_t * p.albedo;
- cur_d *= p.density * step_size;
-
-#if defined(_RAYMARCHED_FOG_HEIGHT_DENSITY)
- float height_clamped = max(pp.y - p.height_density_start, 0);
- // if half_life = 2 and start = 0, then
- // y=2 -> density = 1/2
- // y=4 -> density = 1/4
- // y=6 -> density = 1/8
- // if half_life = 3 and start = 0, then
- // y=3 -> density = 1/2
- // y=6 -> density = 1/4
- // y=9 -> density = 1/8
- float exponent = height_clamped / p.height_density_half_life;
- float factor = pow(2, -exponent);
-#if defined(_CUSTOM30_FOG_HEIGHT_DENSITY_MINIMUM)
- factor = max(factor, p.height_density_minimum);
-#endif
- cur_d *= factor;
-#endif
+ // Analytic integration over the segment
+ float exp_term = exp(-sigma_t * dithered_step);
- cur_d = saturate(cur_d);
+ // If the segment is almost transparent, skip expensive work
+ if (sigma_t < 1e-6)
+ {
+ T *= exp_term;
+ continue;
+ }
+ // --- Incoming radiance ------------------------------------------------
+ float3 L_in;
#if defined(_RAYMARCHED_FOG_EMITTER_TEXTURE)
- float4 cur_c = float4(getEmitterData(p, pp) * cur_d, cur_d);
+ L_in = getEmitterData(p, pp);
#else
- float4 cur_c = float4(p.color * cur_d, cur_d);
+ // Indirect from SH / light volumes
+ float3 l00, l01r, l01g, l01b;
+ LightVolumeSH(pp, l00, l01r, l01g, l01b);
+ float3 indirect = LightVolumeEvaluate(float3(0, 1, 0), l00, l01r, l01g, l01b);
+
+ // Direct from the dominant realtime light
+ float3 to_light = (_WorldSpaceLightPos0.w == 0.0) ? normalize(_WorldSpaceLightPos0.xyz)
+ : normalize(_WorldSpaceLightPos0.xyz - pp);
+ float phase = PhaseHG(dot(to_light, -rd), p.g);
+ float3 direct = _LightColor0.rgb * phase;
+
+ L_in = (direct + indirect) * p.color;
#endif
- color += (1.0f - color.a) * cur_c;
+
+ // --- Accumulate radiance ---------------------------------------------
+ float scattering_integral = (sigma_s / sigma_t) * (1.0 - exp_term);
+ L += T * scattering_integral * L_in;
+
+ // Update transmittance
+ T *= exp_term;
+
+ // Early exit if virtually opaque
+ if (T < 1e-3)
+ break;
+
+ // Grow step size exponentially
+ step_size *= step_growth;
}
+
+ float4 color;
+ color.rgb = L;
+ color.a = 1 - T; // Alpha for proper compositing
FogResult r;
r.color = color;
diff --git a/globals.cginc b/globals.cginc
index 8c11d15..e18e796 100644
--- a/globals.cginc
+++ b/globals.cginc
@@ -563,16 +563,14 @@ texture3D _Raymarched_Fog_Density_Noise;
float4 _Raymarched_Fog_Density_Noise_Scale;
float _Raymarched_Fog_Y_Cutoff;
float3 _Raymarched_Fog_Velocity;
-#if defined(_RAYMARCHED_FOG_DENSITY_EXPONENT)
-float _Raymarched_Fog_Density_Exponent;
-#endif
-#if defined(_RAYMARCHED_FOG_HEIGHT_DENSITY)
-float _Raymarched_Fog_Height_Density_Start;
-float _Raymarched_Fog_Height_Density_Half_Life;
-#endif
-#if defined(_CUSTOM30_FOG_HEIGHT_DENSITY_MINIMUM)
-float _Custom30_Fog_Height_Density_Minimum;
-#endif
+float _Raymarched_Fog_Mean_Free_Path;
+float _Raymarched_Fog_Albedo;
+float _Raymarched_Fog_G;
+float _Raymarched_Fog_Height_Scale;
+float _Raymarched_Fog_Height_Offset;
+float _Raymarched_Fog_Turbulence;
+float _Raymarched_Fog_Step_Size;
+float _Raymarched_Fog_Step_Growth;
#if defined(_RAYMARCHED_FOG_EMITTER_TEXTURE)
texture2D _Raymarched_Fog_Emitter_Texture;
float4 _Raymarched_Fog_Emitter_Texture_TexelSize;
generated by cgit v1.2.3 (git 2.39.1) at 2026-06-01 09:46:00 +0000