Implement wrapped lighting (direct & IBL diffuse)

1 files changed, 5 insertions, 4 deletions

diff --git a/math.cginc b/math.cginc
index 02d0fe0..3d7e92e 100755
--- a/math.cginc
+++ b/math.cginc
@@ -32,15 +32,16 @@ float sin_noise_3d_fbm(float3 uvw, uint octaves, float k, float strength) {
   return result;
 }
 
-// Wrap a dot product. Assume it's already clamped.
+// Wrap NoL. Assume it's already clamped.
 // At k=0, you get standard lambertian shading.
 // At k=0.5, you get half-lambertian shading.
 // At k=1.0, you get flat shading.
 // k must be on [0, 1].
 // Energy preserving, within some small bound.
-float wrapDotProduct(float XoY, float k) {
-  float lambertian = XoY;
-  float half_lambertian = pow(max(1e-4, (XoY + 0.5f) / (1.0f + 0.5f)), 2);
+float wrapNoL(float NoL, float k) {
+  float lambertian = NoL;
+  float tmp = (NoL + 0.5f) / (1.0f + 0.5f);
+  float half_lambertian = tmp * tmp;
   float flat = RCP_PI;
 
   if (k < 0.5) {