Added terrain and basic terrain textures

Assets/Filamented/FilamentCommonLighting.cginc

@@ -0,0 +1,79 @@
+#ifndef FILAMENT_COMMON_LIGHTING
+#define FILAMENT_COMMON_LIGHTING
+
+struct Light {
+    float4 colorIntensity;  // rgb, pre-exposed intensity
+    float3 l;
+    half attenuation;
+    half NoL;
+    float3 worldPosition;
+};
+
+struct PixelParams {
+    half3  diffuseColor;
+    half perceptualRoughness;
+    half perceptualRoughnessUnclamped;
+    half3  f0;
+    half roughness;
+    half3  dfg;
+    half3  energyCompensation;
+
+#if defined(MATERIAL_HAS_CLEAR_COAT)
+    half clearCoat;
+    half clearCoatPerceptualRoughness;
+    half clearCoatRoughness;
+#endif
+
+#if defined(MATERIAL_HAS_SHEEN_COLOR)
+    half3  sheenColor;
+#if !defined(SHADING_MODEL_CLOTH)
+    half sheenRoughness;
+    half sheenPerceptualRoughness;
+    half sheenScaling;
+    half sheenDFG;
+#endif
+#endif
+
+#if defined(MATERIAL_HAS_ANISOTROPY)
+    half3  anisotropicT;
+    half3  anisotropicB;
+    half anisotropy;
+#endif
+
+#if defined(SHADING_MODEL_SUBSURFACE) || defined(HAS_REFRACTION)
+    half thickness;
+#endif
+#if defined(SHADING_MODEL_SUBSURFACE)
+    half3  subsurfaceColor;
+    half subsurfacePower;
+#endif
+
+#if defined(SHADING_MODEL_CLOTH) && defined(MATERIAL_HAS_SUBSURFACE_COLOR)
+    half3  subsurfaceColor;
+#endif
+
+#if defined(HAS_REFRACTION)
+    half etaRI;
+    half etaIR;
+    half transmission;
+    half uThickness;
+    half3 absorption;
+#endif
+
+#if defined(MATERIAL_HAS_GLINT)
+    float2 uv;
+    float2 ddx_uv;
+    float2 ddy_uv;
+    float  glintAlpha;
+    float  glintDensity;
+#endif
+};
+
+half computeMicroShadowing(half NoL, half visibility) {
+    // Chan 2018, "Material Advances in Call of Duty: WWII"
+    half aperture = rsqrt(1.0 - visibility);
+    half microShadow = saturate(NoL * aperture);
+    return microShadow * microShadow;
+};
+
+#endif // FILAMENT_COMMON_LIGHTING