More tangent changes

res/shaders/lib/LightEnv.slang

@@ -14,8 +14,8 @@ struct DirectionalLight : ILightEnv
 
     float3 illuminate<B:IBRDF>(LightingParameter params, B brdf)
     {
-        float3 dir_TS = mul(params.worldToTangent, -normalize(direction.xyz));
-        return brdf.evaluate(params.viewDir_TS, dir_TS, color.xyz);
+        float3 dir_WS = normalize(direction.xyz);
+        return brdf.evaluate(params.tangentToWorld, params.viewDir_WS, dir_WS, color.xyz);
     }
 };
 
@@ -26,11 +26,10 @@ struct PointLight : ILightEnv
     
     float3 illuminate<B:IBRDF>(LightingParameter params, B brdf)
     {
-        float3 pos_TS = mul(params.worldToTangent, position_WS.xyz);
-        float3 lightDir_TS = pos_TS.xyz - params.position_TS;
-        float d = length(lightDir_TS);
+        float3 lightDir_WS = position_WS.xyz - params.position_WS;
+        float d = length(lightDir_WS);
         float illuminance = max(1 - d / colorRange.w, 0);
-        return illuminance * brdf.evaluate(params.viewDir_TS, normalize(lightDir_TS), colorRange.xyz);
+        return illuminance * brdf.evaluate(params.tangentToWorld, params.viewDir_WS, normalize(lightDir_WS), colorRange.xyz);
     }
 
     bool insidePlane(Plane plane, float3 position)