Unity Shader实现素描风格的渲染

本文实例为大家分享了unity shader实现素描风格的具体代码，供大家参考，具体内容如下

原理

使用6张素描纹理进行渲染，在渲染阶段，在顶点着色阶段计算逐顶点的光照，根据光照结果决定6张纹理的混合权重，并传递给片元着色器。在片元着色器中根据这些权重来混合6张纹理的采样结果

shader实现

shader "hatching" 
{
 properties {
 _color ("color tint", color) = (1, 1, 1, 1)//颜色
 _tilefactor ("tile factor", float) = 1//纹理的平铺系数，数值越大素描线条越密
 _outline ("outline", range(0, 1)) = 0.1
 _hatch0 ("hatch 0", 2d) = "white" {}
 _hatch1 ("hatch 1", 2d) = "white" {}
 _hatch2 ("hatch 2", 2d) = "white" {}
 _hatch3 ("hatch 3", 2d) = "white" {}
 _hatch4 ("hatch 4", 2d) = "white" {}
 _hatch5 ("hatch 5", 2d) = "white" {}//对应的6张素描纹理
 }
 
 subshader {
 tags { "rendertype"="opaque" "queue"="geometry"}
 
 
 pass {
 tags { "lightmode"="forwardbase" }
 
 cgprogram
 
 #pragma vertex vert
 #pragma fragment frag 
 
 #pragma multi_compile_fwdbase
 
 #include "unitycg.cginc"
 #include "lighting.cginc"
 #include "autolight.cginc"
 #include "unityshadervariables.cginc"
 
 fixed4 _color;
 float _tilefactor;
 sampler2d _hatch0;
 sampler2d _hatch1;
 sampler2d _hatch2;
 sampler2d _hatch3;
 sampler2d _hatch4;
 sampler2d _hatch5;
 
 struct a2v {
 float4 vertex : position;
 float4 tangent : tangent; 
 float3 normal : normal; 
 float2 texcoord : texcoord0; 
 };
 
 struct v2f {
 float4 pos : sv_position;
 float2 uv : texcoord0;
 fixed3 hatchweights0 : texcoord1;//
 fixed3 hatchweights1 : texcoord2;// 6个混合权重，存在两个fixed3变量中
 float3 worldpos : texcoord3;
 shadow_coords(4)
 };
 
 v2f vert(a2v v) {
 v2f o;
 
 o.pos = unityobjecttoclippos(v.vertex);
 
 o.uv = v.texcoord.xy * _tilefactor;
 
 fixed3 worldlightdir = normalize(worldspacelightdir(v.vertex));
 fixed3 worldnormal = unityobjecttoworldnormal(v.normal);
 fixed diff = max(0, dot(worldlightdir, worldnormal));//漫反射系数
 
 o.hatchweights0 = fixed3(0, 0, 0);
 o.hatchweights1 = fixed3(0, 0, 0);
 
 float hatchfactor = diff * 7.0;//把diff缩放到[0,7]范围
 
 //纯白
 if (hatchfactor > 6.0) 
 {
 
 } else if (hatchfactor > 5.0) {
  o.hatchweights0.x = hatchfactor - 5.0;
 } else if (hatchfactor > 4.0) {
  o.hatchweights0.x = hatchfactor - 4.0;
  o.hatchweights0.y = 1.0 - o.hatchweights0.x;
 } else if (hatchfactor > 3.0) {
  o.hatchweights0.y = hatchfactor - 3.0;
  o.hatchweights0.z = 1.0 - o.hatchweights0.y;
 } else if (hatchfactor > 2.0) {
  o.hatchweights0.z = hatchfactor - 2.0;
  o.hatchweights1.x = 1.0 - o.hatchweights0.z;
 } else if (hatchfactor > 1.0) {
  o.hatchweights1.x = hatchfactor - 1.0;
  o.hatchweights1.y = 1.0 - o.hatchweights1.x;
 } else {
  o.hatchweights1.y = hatchfactor;
  o.hatchweights1.z = 1.0 - o.hatchweights1.y;
 }
 
 o.worldpos = mul(unity_objecttoworld, v.vertex).xyz;
 
 transfer_shadow(o);
 
 return o; 
 }
 
 fixed4 frag(v2f i) : sv_target 
 { //根据相应的权重进行采样
 fixed4 hatchtex0 = tex2d(_hatch0, i.uv) * i.hatchweights0.x;
 fixed4 hatchtex1 = tex2d(_hatch1, i.uv) * i.hatchweights0.y;
 fixed4 hatchtex2 = tex2d(_hatch2, i.uv) * i.hatchweights0.z;
 fixed4 hatchtex3 = tex2d(_hatch3, i.uv) * i.hatchweights1.x;
 fixed4 hatchtex4 = tex2d(_hatch4, i.uv) * i.hatchweights1.y;
 fixed4 hatchtex5 = tex2d(_hatch5, i.uv) * i.hatchweights1.z;
 fixed4 whitecolor = fixed4(1, 1, 1, 1) * (1 - i.hatchweights0.x - i.hatchweights0.y - i.hatchweights0.z - 
  i.hatchweights1.x - i.hatchweights1.y - i.hatchweights1.z);
 
 fixed4 hatchcolor = hatchtex0 + hatchtex1 + hatchtex2 + hatchtex3 + hatchtex4 + hatchtex5 + whitecolor;
 
 unity_light_attenuation(atten, i, i.worldpos);
  
 return fixed4(hatchcolor.rgb * _color.rgb * atten, 1.0);
 }
 
 endcg
 }
 }
 fallback "diffuse"
}

效果如下：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。