Add fallback cubemap feature

1 files changed, 19 insertions, 3 deletions

diff --git a/yum_lighting.cginc b/yum_lighting.cginc
index 8570488..759eee6 100644
--- a/yum_lighting.cginc
+++ b/yum_lighting.cginc
@@ -100,7 +100,7 @@ float3 getDirectLightDirection(v2f i) {
 }

 

 float GetLodRoughness(float roughness) {

-	return (1.0 / UNITY_SPECCUBE_LOD_STEPS) * roughness * (1.7 - 0.7 * roughness);

+	return roughness * (1.7 - 0.7 * roughness);

 }

 

 float3 getIndirectSpecular(v2f i, YumPbr pbr, float3 view_dir) {

@@ -122,8 +122,24 @@ float3 getIndirectSpecular(v2f i, YumPbr pbr, float3 view_dir) {
   data.boxMin[1] = unity_SpecCube1_BoxMin;

   data.probePosition[1] = unity_SpecCube1_ProbePosition;

 #endif

-  return UnityGI_prefilteredRadiance(data, pbr.roughness_perceptual,

-      reflect_dir);

+

+#if defined(_FALLBACK_CUBEMAP)

+  // Check if there's no valid scene cubemap

+  if (!SceneHasReflections() || _Fallback_Cubemap_Force) {

+    // Set up data for fallback sampling similar to Unity's system

+    half3 reflectVector = reflect(-view_dir, pbr.normal);

+    

+    #ifdef UNITY_SPECCUBE_BOX_PROJECTION

+      reflectVector = BoxProjectedCubemapDirection(reflectVector, data.worldPos, data.probePosition[0], data.boxMin[0], data.boxMax[0]);

+    #endif

+

+    half mip = roughness * UNITY_SPECCUBE_LOD_STEPS;

+    float4 envSample = UNITY_SAMPLE_TEXCUBE_LOD(_Fallback_Cubemap, reflectVector, mip);

+    return DecodeHDR(envSample, _Fallback_Cubemap_HDR) * _Fallback_Cubemap_Brightness;

+  }

+#endif

+

+  return UnityGI_prefilteredRadiance(data, roughness, reflect_dir);

 }

 

 float4 getIndirectDiffuse(v2f i, float4 vertexLightColor) {