diff --git a/Assignments/Assignment1/Application1.cpp b/Assignments/Assignment1/Application1.cpp
index 1b1c7d6..2c8a86d 100644
--- a/Assignments/Assignment1/Application1.cpp
+++ b/Assignments/Assignment1/Application1.cpp
@@ -161,9 +161,9 @@ Vec3fa Application1::renderPixelNextEventEstimation(float x, float y, const ISPC
             
         /* sample BRDF at hit point */
         Vec2f uv = RandomSampler_get2D(sampler);
-        Sample3f wi = cosineSampleHemisphere(uv.x, uv.y, sample.Ng);
+        Sample3f wi;
         
-        Vec3fa diffuse = Material__eval(material_array, matId, brdf, wo, sample, wi.v);
+        Vec3fa diffuse = Material__sample(material_array, matId, brdf, Lw, wo, sample, wi, uv);
 
         Lw *= M_PI * diffuse;
 
@@ -226,9 +226,9 @@ Vec3fa Application1::renderPixelPathTracer(float x, float y, const ISPCCamera& c
         /* sample BRDF at hit point */
 
         Vec2f uv = RandomSampler_get2D(sampler);
-        Sample3f wi = cosineSampleHemisphere(uv.x, uv.y, sample.Ng);
+        Sample3f wi;
         
-        Vec3fa diffuse = Material__eval(material_array, matId, brdf, wo, sample, wi.v);
+        Vec3fa diffuse = Material__sample(material_array, matId, brdf, Lw, wo, sample, wi, uv);
 
         Lw *= M_PI * diffuse;