2025-06-08 00:39:11 +09:00

134 lines
3.7 KiB
Plaintext

Shader "Hidden/VolumetricFog2/DistantFog"
{
Properties
{
[HideInInspector] _MainTex("Main Texture", 2D) = "white" {}
[HideInInspector] _Color("Color", Color) = (1,1,1)
[HideInInspector] _DistantFogData("Distant Fog Data", Vector) = (100,0.1,400,0.5)
[HideInInspector] _DistantFogData2("Base Altitude", Vector) = (0, 1, 0, 0)
[HideInInspector] _LightColor("Light Color", Color) = (1,1,1)
[HideInInspector] _LightDiffusionData("Sun Diffusion Data", Vector) = (32, 0.4, 100)
[HideInInspector] _SunDir("Sun Direction", Vector) = (1,0,0)
}
SubShader
{
Tags { "RenderType" = "Transparent" "Queue" = "Transparent-1" "DisableBatching" = "True" "IgnoreProjector" = "True" "RenderPipeline" = "UniversalPipeline" }
Blend SrcAlpha OneMinusSrcAlpha
ZTest Always
Cull Off
ZWrite Off
ZClip False
Pass
{
Name "Distant Fog"
Tags { "LightMode" = "UniversalForward" }
HLSLPROGRAM
#pragma prefer_hlslcc gles
#pragma exclude_renderers d3d11_9x
#pragma target 3.0
#pragma vertex vert
#pragma fragment frag
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/DeclareDepthTexture.hlsl"
#include "CommonsURP.hlsl"
#include "Input.hlsl"
#include "Primitives.cginc"
#include "Raymarch2D.cginc"
float4 _DistantFogData;
#define START_DISTANCE _DistantFogData.x
#define DISTANCE_DENSITY _DistantFogData.y
#define MAX_HEIGHT _DistantFogData.z
#define HEIGHT_DENSITY _DistantFogData.w
float4 _DistantFogData2;
#define BASE_ALTITUDE _DistantFogData2.x
#define MIN_ALTITUDE _DistantFogData2.y
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
UNITY_VERTEX_INPUT_INSTANCE_ID
};
struct v2f
{
float4 pos : SV_POSITION;
float4 scrPos : TEXCOORD0;
UNITY_VERTEX_INPUT_INSTANCE_ID
UNITY_VERTEX_OUTPUT_STEREO
};
v2f vert(appdata v)
{
v2f o;
UNITY_SETUP_INSTANCE_ID(v);
UNITY_TRANSFER_INSTANCE_ID(v, o);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
o.pos = TransformObjectToHClip(v.vertex.xyz);
o.scrPos = ComputeScreenPos(o.pos);
#if defined(UNITY_REVERSED_Z)
o.pos.z = o.pos.w * UNITY_NEAR_CLIP_VALUE * 0.99995; // 0.99999 avoids precision issues on some Android devices causing unexpected clipping of light mesh
#else
o.pos.z = o.pos.w - 0.000005;
#endif
return o;
}
half4 frag(v2f i) : SV_Target {
UNITY_SETUP_INSTANCE_ID(i);
UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX(i);
float2 uv = i.scrPos.xy / i.scrPos.w;
#if UNITY_REVERSED_Z
float depth = GetRawDepth(uv);
#else
float depth = GetRawDepth(uv);
depth = depth * 2.0 - 1.0;
#endif
uv.y = VF2_FLIP_DEPTH_TEXTURE ? 1.0 - uv.y : uv.y;
float3 wpos = ComputeWorldSpacePosition(uv, depth, unity_MatrixInvVP);
float3 rayStart = GetRayStart(wpos);
float3 ray = wpos - rayStart;
float t1 = length(ray);
float3 rayDir = ray / t1;
float3 hitPos = t1 * rayDir;
float maxZ = _ProjectionParams.z - 10;
float startDistance = min(maxZ, START_DISTANCE);
float d = (t1 - startDistance) * DISTANCE_DENSITY;
float hitPosY = max(MIN_ALTITUDE, hitPos.y + rayStart.y - BASE_ALTITUDE);
float h = (hitPosY != 0 ? MAX_HEIGHT / abs(hitPosY) : MAX_HEIGHT) * HEIGHT_DENSITY;
float f = min(d, h);
f = max(f, 0);
half sum = exp2(-f);
sum = 1.0 - saturate(sum);
half4 color = half4(_Color.rgb, sum * _Color.a);
if (t1 > maxZ) { // skybox
half diffusionIntensity = GetDiffusionIntensity(rayDir);
color.rgb += diffusionIntensity;
}
color.rgb *= _LightColor.rgb;
return color;
}
ENDHLSL
}
}
}