Try to avoid NaN in dominant direction calculation

1 files changed, 8 insertions, 0 deletions

diff --git a/lighting.cginc b/lighting.cginc
index 0287f51..8b6693c 100755
--- a/lighting.cginc
+++ b/lighting.cginc
@@ -145,7 +145,15 @@ float4 getIndirectDiffuse(v2f i, Pbr pbr, inout LightData light) {
   );
   // Multiply unit vector by L1 matrix to get vector pointing in direction of
   // light.
+  float3 raw_dir = mul(mat, float3(1,1,1));
+  float raw_dir_len = length(raw_dir);
   float3 dom_dir = normalize(mul(mat, float3(1,1,1)));
+  if (abs(raw_dir_len) < 1e-3) {
+    dom_dir = light.direct.dir;
+  } else {
+    dom_dir = raw_dir;
+  }
+  dom_dir = normalize(dom_dir);
   light.indirect.diffuse_dominant_dir = dom_dir;
 #endif