前言
【本文持续更新中】
终于把一直想做一做的仿原神渲染做了一下。
原神出来也有段时间了，各路大佬的逆向早就做完了，所以最近做的其实复刻大佬们的工程，难度并不大。
废话不多说，先看效果。
Unity
UE
（UE的边缘光老是闪就关了）
两个版本都没有加上雾效，泛光之间的后处理效果，本篇随笔也不会讲述相关内容，有能力的可以自己加上，效果应该会上一个档次
UE最近一段时间才开始用起来，材质蓝图比我想象的要简单一些，但是UE的PBR渲染几乎是高度封装的，导致几乎相同的流程UE会和Unity效果差异很明显。
这次的UE版本效果也就差强人意吧，后续继续做UE项目的话可能会改进。
贴图、模型什么的网上一找就能找到，实在找不到就评论区或者私信问我吧，本随笔默认已经准备好所有模型贴图。
概念
- Matcap
- ILM
- Ramp
- Rim
- fresnel
实现流程
源码
1 Shader "Custom/Cel_Base"
2 {
3 Properties
4 {
5 _AmbientColor ("Ambient Color", Color) = (1,1,1,1)
6 _AmbientFac("Ambient Fac", Range(0, 1)) = 0
7 _SphereTex("Sphere Tex", 2D) = "white" {}
8 _SphereTexFac("Sphere Fac", Range(0, 1)) = 0
9 _OutlineOffset("Outline Offset", Float) = 0.01
10 _OutlineShadowColor("Outline Shadow", Color) = (1, 1, 1, 1)
11 _BaseTex ("Base Tex", 2D) = "white" {}
12 [Toggle(_True)]_IsSkin("Is Skin", Float) = 1
13 _ToonTex ("Toon Tex", 2D) = "white" {}
14 _SkinTex ("Skin Tex", 2D) = "white" {}
15 _MatcapFac("Matcap Fac", Range(0, 1)) = 0
16 _MetalTex("Metal Tex", 2D) = "white" {}
17 _ILM_Tex("ILM Tex", 2D) = "white" {}
18 _ILM_R_TMP("ILM R", 2D) = "white" {}
19 [Toggle(_True)]_IsEye("Is Eye", Float) = 1
20 _Eye_Mask_Tex("Eye Mask Tex", 2D) = "white" {}
21 _Gloss("Gloss", Float) = 50
22 _KsNonMetallic("Non Metallic", Float) = 1
23 _KsMetallic("Metallic", Float) = 1
24 _KsHairMetallic("Hair Metallic", Float) = 1
25 [Toggle(_True)]_IsHair("Is Hair", Float) = 1
26 _RampTex ("Ramp Tex", 2D) = "white" {}
27 _ShadowColor ("Shadow Color", Color) = (1, 1, 1, 1)
28 _RimColor ("Rim Color", Color) = (1, 1, 1, 1)
29 _RimFac ("Rim Fac", Float) = 0
30
31 }
32 SubShader
33 {
34 Tags {"LightMode" = "ForwardBase" "RenderType" = "Opaque" }
35 Pass
36 {
37 Cull Off
38 CGPROGRAM
39 #include "UnityCG.cginc"
40 #include "Lighting.cginc"
41 #include "AutoLight.cginc"
42
43 #pragma vertex vert
44 #pragma fragment frag
45 #pragma multi_compile_fwdbase
46
47 sampler2D _CameraDepthTexture;
48
49 sampler2D _BaseTex;
50 sampler2D _ToonTex;
51 sampler2D _RampTex;
52 sampler2D _SkinTex;
53 sampler2D _SphereTex;
54 sampler2D _ILM_Tex;
55 sampler2D _ILM_R_TMP;
56 sampler2D _MetalTex;
57 float4 _AmbientColor;
58 float4 _ShadowColor;
59 float4 _RimColor;
60 float _MatcapFac;
61 float _AmbientFac;
62 float _SphereTexFac;
63 float _Gloss;
64 float _KsNonMetallic;
65 float _KsMetallic;
66 float _KsHairMetallic;
67 float _IsHair;
68 float _IsSkin;
69 float _RimFac;
70
71 struct a2v
72 {
73 float4 vertex : POSITION;
74 float3 normal : NORMAL;
75 float2 texcoord : TEXCOORD0;
76 };
77
78 struct v2f
79 {
80 float4 pos : SV_POSITION;
81 float4 scrPos : TEXCOORD3;
82 float4 worldPos : TEXCOORD2;
83 float3 worldNormal : TEXCOORD1;
84 float2 uv : TEXCOORD0;
85 SHADOW_COORDS(4)
86 };
87
88 v2f vert(a2v v)
89 {
90 v2f o;
91 o.pos = UnityObjectToClipPos(v.vertex);
92 o.scrPos = ComputeScreenPos(o.pos);
93 o.uv = v.texcoord;
94 o.worldPos = mul(unity_ObjectToWorld, v.vertex);
95 o.worldNormal = mul(unity_ObjectToWorld, v.normal);
96 TRANSFER_SHADOW(o);
97 return o;
98 }
99
100 float4 frag(v2f i) : SV_Target
101 {
102 UNITY_LIGHT_ATTENUATION(atten, i, i.worldPos);
103 //Context
104 float3 LightDir = normalize(_WorldSpaceLightPos0);
105 float3 ViewDir = normalize(_WorldSpaceCameraPos);
106 float3 viewNormal = mul(unity_WorldToCamera, i.worldNormal);
107 float NOL = dot(i.worldNormal, LightDir);
108 float NOV = dot(i.worldNormal, ViewDir);
109
110 //Lambert HalfLambert
111 float Lambert = max(0, NOL);
112 float HalfLambert = pow((NOL * 0.5 + 0.5), 1);
113
114 //Ramp采样用 HalfLambert_Ramp
115
116 float HalfLambert_Ramp = smoothstep(0.0, 0.5, HalfLambert);
117
118 //DarkRamp平滑用 LambertStep
119 float LambertStep = smoothstep(0.423, 0.465, HalfLambert);
120
121 //BaseColor
122 float4 BaseTexColor = tex2D(_BaseTex, i.uv);
123 //return float4(BaseTexColor.rgb, 1);
124
125 //MatcapUV
126 float3 ViewDir_CameraSpace = mul(unity_WorldToCamera, i.worldNormal);
127 ViewDir_CameraSpace = ViewDir_CameraSpace * 0.5 + 0.5;
128 float2 MatcapUV = ViewDir_CameraSpace.xy;
129
130 //ToonColor SkinColor
131 float3 ToonColor = tex2D(_ToonTex, MatcapUV);
132 float3 SkinColor = tex2D(_SkinTex, MatcapUV);
133
134 //MatcapColor
135 float3 MatcapColor;
136 if (_IsSkin == 1) MatcapColor = SkinColor;
137 else MatcapColor = ToonColor;
138
139 //BaseColor
140 float3 BaseColor = lerp(BaseTexColor, BaseTexColor * MatcapColor, _MatcapFac);
141 BaseColor = lerp(BaseColor, BaseColor * _AmbientColor, _AmbientFac);
142 float3 SphereColor = tex2D(_SphereTex, MatcapUV);
143 BaseColor = lerp(BaseColor, BaseColor * SphereColor, _SphereTexFac);
144
145 //ILM
146 float4 ILM_RGBA = tex2D(_ILM_Tex, i.uv);
147 float ILM_R = ILM_RGBA.x;
148 float ILM_G = ILM_RGBA.y;
149 float ILM_B = ILM_RGBA.z;
150 float ILM_A = ILM_RGBA.w;
151
152 //NightRamp_V
153 float ILM_Alpha_0 = 0.15;
154 float ILM_Alpha_1 = 0.40;
155 float ILM_Alpha_2 = 0.60;
156 float ILM_Alpha_3 = 0.85;
157 float ILM_Alpha_4 = 1.0;
158 float ILM_Value_0 = 1.0;
159 float ILM_Value_1 = 4.0;
160 float ILM_Value_2 = 3.0;
161 float ILM_Value_3 = 5.0;
162 float ILM_Value_4 = 2.0;
163 ILM_Value_0 = 0.55 - ILM_Value_0 / 10;
164 ILM_Value_1 = 0.55 - ILM_Value_1 / 10;
165 ILM_Value_2 = 0.55 - ILM_Value_2 / 10;
166 ILM_Value_3 = 0.55 - ILM_Value_3 / 10;
167 ILM_Value_4 = 0.55 - ILM_Value_4 / 10;
168 float NightRamp_V = lerp(ILM_Value_4, ILM_Value_3, step(ILM_A, ILM_Alpha_3));
169 NightRamp_V = lerp(NightRamp_V, ILM_Value_2, step(ILM_A, ILM_Alpha_2));
170 NightRamp_V = lerp(NightRamp_V, ILM_Value_1, step(ILM_A, ILM_Alpha_1));
171 NightRamp_V = lerp(NightRamp_V, ILM_Value_0, step(ILM_A, ILM_Alpha_0));
172
173 //DayRamp_V
174 float DayRamp_V = NightRamp_V + 0.5;
175
176 //IsDay
177 float IsDay = (LightDir.y + 1) / 2;
178
179 //RampColor
180 //采样Ramp时，HalfLmabert * AO可以得到带 AO的 RampColor
181 float3 DayRampColor = tex2D(_RampTex, float2(HalfLambert_Ramp, DayRamp_V));
182 float3 DayDarkRampColor = tex2D(_RampTex, float2(0.003, DayRamp_V));
183 float3 NightRampColor = tex2D(_RampTex, float2(HalfLambert_Ramp, NightRamp_V));
184 float3 NightDarkRampColor = tex2D(_RampTex, float2(0.003, NightRamp_V));
185 float3 RampColor = lerp(NightRampColor, DayRampColor, IsDay);
186 float3 DarkRampColor = lerp(NightDarkRampColor, DayDarkRampColor, IsDay);
187
188 //Diffuse
189 //使用 LambertStep平滑
190 float3 Diffuse = lerp(BaseColor * RampColor * _ShadowColor, BaseColor, LambertStep);
191 Diffuse = lerp(BaseColor * DarkRampColor * _ShadowColor, Diffuse, 1);
192 //使用 ILM_G增加AO，同时AO使用Ramp图最左侧颜色
193 //ILM_G范围为 0-0.5，大于等于0.5的部分为非AO部分，故映射为 0-1
194 Diffuse = lerp(BaseColor * DarkRampColor * _ShadowColor, Diffuse, ILM_G * 2);
195
196
197 //BlinnPhong
198 float3 HalfDir = normalize(ViewDir + LightDir);
199 float NOH = dot(i.worldNormal, HalfDir);
200 float BlinnPhong = step(0, NOL) * pow(max(0, NOH), _Gloss);
201
202 //IsMetallic
203 float IsMetallic = step(0.95, ILM_R);
204 float ILM_Hair_R = tex2D(_ILM_R_TMP, i.uv).r;
205
206 //Specular
207 float NonMetallic_Specular = step(1.04 - BlinnPhong, ILM_B) * ILM_R * _KsNonMetallic;
208 float3 HairMetallic_Specular = 0;
209 if (_IsHair == 1) HairMetallic_Specular = ILM_B * LambertStep * BaseColor * ILM_Hair_R * _KsHairMetallic;
210 float3 KsMetallic_Specular = BlinnPhong * ILM_B * (LambertStep * 0.8 + 0.2) * BaseColor * _KsMetallic;
211 float3 Specular = lerp(NonMetallic_Specular + HairMetallic_Specular, KsMetallic_Specular, IsMetallic);
212
213 //Metallic
214 float3 Metallic = lerp(0, tex2D(_MetalTex, MatcapUV).r * BaseColor, IsMetallic);
215
216 //Albedo
217 float3 Albedo = Diffuse + Specular + Metallic;
218
219 float rimOffset = 13;
220 float rimThreshold = 0.08;
221 float rimStrength = 0.6;
222 float rimMax = 0.3;
223
224 float rawDepth = SAMPLE_DEPTH_TEXTURE_PROJ(_CameraDepthTexture, i.scrPos);
225
226 float linearDepth = LinearEyeDepth(rawDepth);
227 float Offset = lerp(-1, 1, step(0, viewNormal.x)) * rimOffset / _ScreenParams.x;
228 //float Offset = lerp(-1, 1, step(0, viewNormal.x)) * rimOffset / _ScreenParams.x / max(1, pow(linearDepth, 0.5));
229 float4 screenOffset = float4(Offset, 0, 0, 0);
230 float offsetDepth = SAMPLE_DEPTH_TEXTURE_PROJ(_CameraDepthTexture, i.scrPos + screenOffset);
231 float offsetLinearDepth = LinearEyeDepth(offsetDepth);
232
233 float rim = saturate(offsetLinearDepth - linearDepth);
234 rim = step(rimThreshold, rim) * clamp(rim * rimStrength, 0, rimMax);
235
236 float fresnelPower = 6;
237 float fresnelClamp = 0.8;
238 float fresnel = 1 - saturate(NOV);
239 fresnel = pow(fresnel, fresnelPower);
240 fresnel = fresnel * fresnelClamp + (1 - fresnelClamp);
241
242 Albedo = 1 - (1 - rim * fresnel * _RimColor * BaseTexColor * _RimFac) * (1 - Albedo);
243
244 float4 FinalColor = float4(Albedo, BaseTexColor.a);
245 return FinalColor;
246 }
247
248 ENDCG
249 }
250
251 Pass
252 {
253 Name "DrawOutline"
254 Tags {"RenderPipeline" = "UniversalPipeline" "RenderType" = "Opaque"}
255 Cull Front
256
257 CGPROGRAM
258
259 #pragma vertex vert
260 #pragma fragment frag
261 #pragma multi_compile_fog
262 #include "UnityCG.cginc"
263
264 sampler2D _BaseTex;
265 sampler2D _ILM_Tex;
266 sampler2D _RampTex;
267 sampler2D _Eye_Mask_Tex;
268
269 float4 _OutlineShadowColor;
270 float _OutlineOffset;
271 float _IsEye;
272
273 float GetCameraFOV()
274 {
275 //https://answers.unity.com/questions/770838/how-can-i-extract-the-fov-information-from-the-pro.html
276 float t = unity_CameraProjection._m11;
277 float Rad2Deg = 180 / 3.1415;
278 float fov = atan(1.0f / t) * 2.0 * Rad2Deg;
279 return fov;
280 }
281 float ApplyOutlineDistanceFadeOut(float inputMulFix)
282 {
283 //make outline "fadeout" if character is too small in camera's view
284 return saturate(inputMulFix);
285 }
286 float GetOutlineCameraFovAndDistanceFixMultiplier(float positionVS_Z)
287 {
288 float cameraMulFix;
289 if(unity_OrthoParams.w == 0)
290 {
291 ////////////////////////////////
292 // Perspective camera case
293 ////////////////////////////////
294
295 // keep outline similar width on screen accoss all camera distance
296 cameraMulFix = abs(positionVS_Z);
297
298 // can replace to a tonemap function if a smooth stop is needed
299 cameraMulFix = ApplyOutlineDistanceFadeOut(cameraMulFix);
300
301 // keep outline similar width on screen accoss all camera fov
302 cameraMulFix *= GetCameraFOV();
303 }
304 else
305 {
306 ////////////////////////////////
307 // Orthographic camera case
308 ////////////////////////////////
309 float orthoSize = abs(unity_OrthoParams.y);
310 orthoSize = ApplyOutlineDistanceFadeOut(orthoSize);
311 cameraMulFix = orthoSize * 50; // 50 is a magic number to match perspective camera's outline width
312 }
313
314 return cameraMulFix * 0.00005; // mul a const to make return result = default normal expand amount WS
315 }
316
317 float3 TransformPositionWSToOutlinePositionWS(float3 positionWS, float positionVS_Z, float3 normalWS)
318 {
319 //you can replace it to your own method! Here we will write a simple world space method for tutorial reason, it is not the best method!
320 float outlineExpandAmount = _OutlineOffset * GetOutlineCameraFovAndDistanceFixMultiplier(positionVS_Z);
321 return positionWS + normalWS * outlineExpandAmount;
322 }
323
324 struct a2v
325 {
326 float4 vertex : POSITION;
327 float3 normal : NORMAL;
328 float4 tangent : TANGENT;
329 float2 uv : TEXCOORD0;
330 float4 uv7 : TEXCOORD7;
331 };
332
333 struct v2f
334 {
335 float4 position : SV_POSITION;
336 float2 uv : TEXCOORD0;
337 };
338
339 v2f vert(a2v v)
340 {
341 v2f o;
342
343 /*float3 worldPos = mul(UNITY_MATRIX_M, v.vertex).xyz;
344 float3 worldNormal = UnityObjectToWorldNormal(v.normal);
345 float3 worldTangent = UnityObjectToWorldDir(v.tangent);
346 float3 worldBinormal = cross(worldNormal, worldTangent) * v.tangent.w;
347 float3 ViewPos = mul((float3x3)UNITY_MATRIX_IT_MV, v.vertex);
348
349 float3x3 tbn = float3x3(worldTangent, worldBinormal, worldNormal);
350 float3 normalWS = mul(v.normal.rgb, tbn);
351
352 float EyeMask = 1;
353 if (_IsEye == 1) EyeMask = tex2Dlod(_Eye_Mask_Tex, float4(v.uv, 0, 0)).a;
354 _OutlineOffset = lerp(0, _OutlineOffset, EyeMask);
355
356 float3 positionWS = TransformPositionWSToOutlinePositionWS(
357 worldPos, ViewPos.z, normalWS);
358
359 o.position = UnityObjectToClipPos(positionWS);
360 o.uv = v.uv;*/
361
362 float4 pos = UnityObjectToClipPos(v.vertex);
363 //float3 viewNormal = mul((float3x3)UNITY_MATRIX_IT_MV, v.uv7.xyz);
364 float3 viewNormal = mul((float3x3)UNITY_MATRIX_IT_MV, v.tangent.xyz);
365 float3 ndcNormal = normalize(TransformViewToProjection(viewNormal.xyz)) * pos.w;//将法线变换到NDC空间
366 float4 nearUpperRight = mul(unity_CameraInvProjection, float4(1, 1, UNITY_NEAR_CLIP_VALUE, _ProjectionParams.y));//将近裁剪面右上角的位置的顶点变换到观察空间
367 float aspect = abs(nearUpperRight.y / nearUpperRight.x);//求得屏幕宽高比
368 ndcNormal.x *= aspect;
369 pos.xy += 0.001 * clamp(_OutlineOffset * ndcNormal.xy, -50, 50);
370
371 o.position = pos;
372 o.uv = v.uv;
373
374 return o;
375 }
376 float4 frag(v2f i) : SV_Target
377 {
378
379 //Context
380 float3 LightDir = normalize(_WorldSpaceLightPos0);
381
382 //BaseColor
383 float4 BaseTexColor = tex2D(_BaseTex, i.uv);
384
385 float4 ILM_RGBA = tex2D(_ILM_Tex, i.uv);
386 float ILM_A = ILM_RGBA.w;
387
388 //NightRamp_V
389 float ILM_Alpha_0 = 0.15;
390 float ILM_Alpha_1 = 0.40;
391 float ILM_Alpha_2 = 0.60;
392 float ILM_Alpha_3 = 0.85;
393 float ILM_Alpha_4 = 1.0;
394 float ILM_Value_0 = 1.0;
395 float ILM_Value_1 = 4.0;
396 float ILM_Value_2 = 3.0;
397 float ILM_Value_3 = 5.0;
398 float ILM_Value_4 = 2.0;
399 ILM_Value_0 = 0.55 - ILM_Value_0 / 10;
400 ILM_Value_1 = 0.55 - ILM_Value_1 / 10;
401 ILM_Value_2 = 0.55 - ILM_Value_2 / 10;
402 ILM_Value_3 = 0.55 - ILM_Value_3 / 10;
403 ILM_Value_4 = 0.55 - ILM_Value_4 / 10;
404 float NightRamp_V = lerp(ILM_Value_4, ILM_Value_3, step(ILM_A, ILM_Alpha_3));
405 NightRamp_V = lerp(NightRamp_V, ILM_Value_2, step(ILM_A, ILM_Alpha_2));
406 NightRamp_V = lerp(NightRamp_V, ILM_Value_1, step(ILM_A, ILM_Alpha_1));
407 NightRamp_V = lerp(NightRamp_V, ILM_Value_0, step(ILM_A, ILM_Alpha_0));
408
409 //DayRamp_V
410 float DayRamp_V = NightRamp_V + 0.5;
411
412 //IsDay
413 float IsDay = (LightDir.y + 1) / 2;
414
415 //RampColor
416 float3 DayDarkRampColor = tex2D(_RampTex, float2(0.003, DayRamp_V));
417 float3 NightDarkRampColor = tex2D(_RampTex, float2(0.003, NightRamp_V));
418 float3 DarkRampColor = lerp(NightDarkRampColor, DayDarkRampColor, IsDay);
419
420
421 return float4(BaseTexColor * DarkRampColor * _OutlineShadowColor, BaseTexColor.a);
422 }
423 ENDCG
424 }
425 }
426 FallBack "Diffuse"
427 }
标签：仿原,float,lerp,ILM,Value,float4,Unity,UE,float3 From： https://www.cnblogs.com/IslandZ/p/17608128.html