192 lines
7.1 KiB
Plaintext
192 lines
7.1 KiB
Plaintext
Shader "IndianOcean/WaterReflection"
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{
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// 水面倒影 Shader
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// 上方 (1-R) 正常显示原图，下方 R 区域为原图整体垂直翻转 + 扰动 + 淡出，
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// 分界线处绘制一条水面亮线。
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Properties
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{
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_MainTex ("主贴图", 2D) = "white" {}
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_Waterline ("水面线位置（UV.y）", Range(0.05, 0.95)) = 0.7
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_DistortStrength("水平扰动强度", Range(0, 0.08)) = 0.015
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_DistortSpeed ("扰动速度", Range(0, 5)) = 1.5
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_DistortFreq ("扰动频率", Range(1, 20)) = 8.0
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_ReflDarken ("倒影变暗系数", Range(0, 1)) = 0.5
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_ReflFadeLen ("倒影向下淡出长度", Range(0, 0.5)) = 0.25
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_LineBrightness ("水面线亮度", Range(0, 3)) = 1.5
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_LineThickness ("水面线粗细", Range(0, 0.02)) = 0.004
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_WaveAmplitude ("水面线波浪振幅", Range(0, 0.05)) = 0.012
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_WaveFreq ("水面线波浪频率", Range(1, 15)) = 4.0
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_WaveSpeed ("水面线波浪速度", Range(0, 5)) = 1.0
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}
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SubShader
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{
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Tags
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{
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"RenderType" = "Transparent"
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"Queue" = "Transparent"
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"RenderPipeline" = "UniversalPipeline"
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}
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Blend SrcAlpha OneMinusSrcAlpha
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ZWrite Off
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Cull Off
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Pass
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{
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Name "WaterReflection"
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HLSLPROGRAM
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#pragma vertex vert
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#pragma fragment frag
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#pragma multi_compile_instancing
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#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
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struct Attributes
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{
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float4 positionOS : POSITION;
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float2 uv : TEXCOORD0;
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float4 color : COLOR;
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UNITY_VERTEX_INPUT_INSTANCE_ID
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};
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struct Varyings
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{
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float4 positionCS : SV_POSITION;
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float2 uv : TEXCOORD0;
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float4 color : COLOR;
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UNITY_VERTEX_INPUT_INSTANCE_ID
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};
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CBUFFER_START(UnityPerMaterial)
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float4 _MainTex_ST;
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float _Waterline;
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float _DistortStrength;
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float _DistortSpeed;
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float _DistortFreq;
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float _ReflDarken;
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float _ReflFadeLen;
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float _LineBrightness;
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float _LineThickness;
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float _WaveAmplitude;
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float _WaveFreq;
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float _WaveSpeed;
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CBUFFER_END
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TEXTURE2D(_MainTex);
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SAMPLER(sampler_MainTex);
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/* ---------- noise ---------- */
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float hash(float n)
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{
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return frac(sin(n) * 43758.5453);
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}
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float noise1D(float x)
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{
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float i = floor(x);
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float f = frac(x);
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f = f * f * (3.0 - 2.0 * f);
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return lerp(hash(i), hash(i + 1.0), f);
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}
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// 多层叠加 → 类随机水面波纹，返回 [-1, 1]
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float waterNoise(float x, float t)
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{
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float n = 0.0;
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n += noise1D(x * _DistortFreq + t * _DistortSpeed) * 0.50;
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n += noise1D(x * _DistortFreq * 2.3 - t * _DistortSpeed * 1.7) * 0.25;
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n += noise1D(x * _DistortFreq * 4.7 + t * _DistortSpeed * 0.8) * 0.125;
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return n * 2.0 - 1.0;
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}
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// 计算某 uv.x 处的局部水面线 Y 坐标（波浪起伏）
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// 多层正弦叠加 + noise，产生自然的不规则波形
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float localWaterline(float x, float t)
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{
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float wave = 0.0;
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wave += sin(x * _WaveFreq * 6.2832 + t * _WaveSpeed) * 0.50;
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wave += sin(x * _WaveFreq * 6.2832 * 2.3 - t * _WaveSpeed * 1.4) * 0.25;
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wave += sin(x * _WaveFreq * 6.2832 * 4.1 + t * _WaveSpeed * 0.7) * 0.15;
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wave += noise1D(x * _WaveFreq * 3.0 + t * _WaveSpeed * 0.5) * 0.10;
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return _Waterline + wave * _WaveAmplitude;
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}
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Varyings vert(Attributes input)
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{
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Varyings output;
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UNITY_SETUP_INSTANCE_ID(input);
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UNITY_TRANSFER_INSTANCE_ID(input, output);
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output.positionCS = TransformObjectToHClip(input.positionOS.xyz);
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output.uv = TRANSFORM_TEX(input.uv, _MainTex);
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output.color = input.color;
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return output;
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}
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half4 frag(Varyings input) : SV_Target
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{
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float2 uv = input.uv;
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float time = _Time.y;
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// ========== 1. 原图采样（上方区域直接使用） ==========
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half4 baseColor = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, uv);
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// ========== 2. 局部水面线（波浪起伏） ==========
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float wl = localWaterline(uv.x, time);
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// ========== 3. 判断是否在倒影区 ==========
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float inRefl = 1.0 - step(wl, uv.y);
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// ========== 4. 倒影 UV：整体垂直翻转 ==========
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float2 reflUV = uv;
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reflUV.y = 2.0 * wl - uv.y; // 以局部水面线为轴镜像
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// 水平扰动
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float distort = waterNoise(uv.x, time) * _DistortStrength;
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// 越远离水面线（越往下）扰动越大
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float depthRatio = 1.0 - uv.y / wl; // 0=水面, 1=最底
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depthRatio = clamp(depthRatio, 0.0, 1.0);
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distort *= (0.3 + 0.7 * depthRatio);
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reflUV.x += distort;
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// 夹紧，防止越界
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reflUV = clamp(reflUV, 0.0, 1.0);
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half4 reflColor = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, reflUV);
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// ========== 5. 倒影衰减 ==========
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// 5a. 整体变暗
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reflColor.rgb *= (1.0 - _ReflDarken);
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// 5b. 从水面线往下逐渐淡出（消散）
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float fadeStart = wl - _ReflFadeLen;
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float fadeFactor = smoothstep(fadeStart, wl, uv.y);
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reflColor.a *= fadeFactor;
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// ========== 6. 水面亮线（沿波浪曲线绘制） ==========
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float distToLine = abs(uv.y - wl);
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float lineFactor = 1.0 - smoothstep(0.0, _LineThickness, distToLine);
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// ========== 7. 合成 ==========
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half3 finalRGB = baseColor.rgb;
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// 倒影区：用倒影色替换
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finalRGB = lerp(finalRGB, reflColor.rgb, inRefl);
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// 水面线：叠加高亮
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finalRGB += lineFactor * _LineBrightness * half3(0.7, 0.85, 1.0);
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float finalA = baseColor.a;
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// 倒影区 alpha 也跟随淡出
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finalA = lerp(finalA, reflColor.a, inRefl);
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half4 finalColor = half4(finalRGB, finalA);
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finalColor *= input.color;
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return finalColor;
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}
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ENDHLSL
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}
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}
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FallBack Off
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}
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