add shader for LWRP

Proc Gen E21/Assets/Scripts/TerrainFragment.shader

@@ -0,0 +1,122 @@
+Shader "Custom/TerrainFragment" {
+
+		SubShader
+	{
+		Tags { "RenderType" = "Opaque" }
+		LOD 200
+
+		Pass
+		{
+			Tags{"LightMode" = "LightweightForward"}
+
+			CGPROGRAM
+			#pragma vertex vert
+			#pragma fragment frag
+			#pragma target 3.0
+			#pragma glsl
+		#pragma multi_compile_fog
+
+		#include "UnityCG.cginc"
+		#include "Lighting.cginc"
+
+	// compile shader into multiple variants, with and without shadows
+	// (we don't care about any lightmaps yet, so skip these variants)
+	#pragma multi_compile_fwdbase nolightmap nodirlightmap nodynlightmap novertexlight
+	// shadow helper functions and macros
+	#include "AutoLight.cginc"
+
+	const static int maxLayerCount = 8;
+	const static float epsilon = 1E-4;
+
+	int layerCount;
+	float3 baseColors[maxLayerCount];
+	float baseStartHeights[maxLayerCount];
+	float baseBlends[maxLayerCount];
+	float baseColorStrength[maxLayerCount];
+	float baseTextureScales[maxLayerCount];
+
+	float minHeight;
+	float maxHeight;
+
+	UNITY_DECLARE_TEX2DARRAY(baseTextures);
+
+	struct v2f
+	{
+		float4 vertex : SV_POSITION;
+		float3 worldPos : TEXCOORD0;
+		half3 worldNormal : TEXCOORD1;
+		fixed4 diff : COLOR0; // diffuse lighting color
+		fixed3 ambient : COLOR1;
+		UNITY_FOG_COORDS(1)
+	};
+
+	float inverseLerp(float a, float b, float value) {
+
+		return saturate((value - a) / (b - a));
+	}
+
+	float3 triplanar(float3 worldPos, float scale, float3 blendAxes, int textureIndex) {
+
+		float3 scaledWorldPos = worldPos / scale;
+		float3 xProjection = UNITY_SAMPLE_TEX2DARRAY(baseTextures, float3(scaledWorldPos.y, scaledWorldPos.z, textureIndex)) * blendAxes.x;
+		float3 yProjection = UNITY_SAMPLE_TEX2DARRAY(baseTextures, float3(scaledWorldPos.x, scaledWorldPos.z, textureIndex)) * blendAxes.y;
+		float3 zProjection = UNITY_SAMPLE_TEX2DARRAY(baseTextures, float3(scaledWorldPos.x, scaledWorldPos.y, textureIndex)) * blendAxes.z;
+		return xProjection + yProjection + zProjection;
+	}
+
+	float getDrawStrength(int index, float heightPercent) {
+
+		float lerpA = -baseBlends[index] / 2.0 - epsilon;
+		float lerpB = baseBlends[index] / 2.0;
+		float lerpC = heightPercent - baseStartHeights[index];
+
+		return  inverseLerp(lerpA, lerpB, lerpC);
+	}
+
+	v2f vert(float4 vertex : POSITION, float3 normal : NORMAL)
+	{
+		v2f o;
+		o.worldPos = mul(unity_ObjectToWorld, vertex);
+		o.vertex = UnityObjectToClipPos(vertex);
+		o.worldNormal = UnityObjectToWorldNormal(normal);
+
+		half nl = max(0, dot(o.worldNormal, _WorldSpaceLightPos0.xyz));
+		// factor in the light color
+		o.diff = nl * _LightColor0;
+		o.ambient = ShadeSH9(half4(o.worldNormal, 1));
+		TRANSFER_SHADOW(o)
+		UNITY_TRANSFER_FOG(o, o.vertex);
+		return o;
+	}
+
+	fixed4 _Color;
+	fixed4 frag(v2f IN) : SV_Target
+	{
+		float heightPercent = inverseLerp(minHeight,maxHeight, IN.worldPos.y);
+		float3 blendAxes = abs(IN.worldNormal);
+		blendAxes /= dot(blendAxes, 1.0);
+
+		for (int i = 0; i < layerCount; i++) {
+			float drawStrength = getDrawStrength(i, heightPercent);
+
+			float3 baseColor = baseColors[i] * baseColorStrength[i];
+			float3 textureColor = triplanar(IN.worldPos, baseTextureScales[i], blendAxes, i) * (1 - baseColorStrength[i]);
+			_Color.rgb = _Color.rgb * (1 - drawStrength) + (baseColor + textureColor) * drawStrength;
+		}
+
+		// compute shadow attenuation (1.0 = fully lit, 0.0 = fully shadowed)
+		fixed shadow = SHADOW_ATTENUATION(IN);
+		// darken light's illumination with shadow, keep ambient intact
+		fixed3 lighting = IN.diff * shadow + IN.ambient;
+		_Color.rgb *= lighting;
+		UNITY_APPLY_FOG(i.fogCoord, _Color);
+
+		// UNITY_APPLY_FOG(IN.fogCoord, _Color);
+		return _Color;
+	}
+	ENDCG
+}
+UsePass "Legacy Shaders/VertexLit/SHADOWCASTER"
+	}
+		FallBack "Diffuse"
+}