diff --git a/Scene/Terrain.cpp b/Scene/Terrain.cpp
index ffede70..00c8cef 100644
--- a/Scene/Terrain.cpp
+++ b/Scene/Terrain.cpp
@@ -73,7 +73,8 @@ Terrain::Terrain(vk::PhysicalDevice phys_dev, vk::Device dev, Texture& tex) : ph
 				- moores_heights[0][2] - 2.0f * moores_heights[1][2] - moores_heights[2][2]
 			);
 			/* fill in missing component, first scalar scales bump */
-			normal.y = 0.25 * glm::sqrt(1.0 -glm::dot(normal, normal));
+			normal.y = 0.25 * glm::sqrt(glm::abs(1.0 - normal.x*normal.x - normal.z*normal.z));
+
 			
 			vertices[x + y * patch_size].norm = glm::normalize(normal * glm::vec3(2.0f, 1.0f, 2.0f));
 		}
diff --git a/UI/UI.cpp b/UI/UI.cpp
index dc3accc..8a84fb4 100644
--- a/UI/UI.cpp
+++ b/UI/UI.cpp
@@ -92,7 +92,7 @@ void UI::newFrame() {
 	ImGui::Text("FPS: %f", info.fps);
 	ImGui::Text("Time: %f", info.time);
 	ImGui::Checkbox("Fly Camera", &info.flycam);
-	ImGui::SliderFloat("Tessellation Factor", &info.tess_factor, 0.0, 20.0);
+	ImGui::SliderFloat("Tessellation Factor", &info.tess_factor, 0.0, 100.0);
 	ImGui::SliderFloat("Edge Size", &info.tess_edge_size, 0.0, 40.0);
 
 	ImGui::End();
diff --git a/assets/shaders/terrain.frag b/assets/shaders/terrain.frag
index c5bd585..333da3b 100644
--- a/assets/shaders/terrain.frag
+++ b/assets/shaders/terrain.frag
@@ -18,5 +18,10 @@ layout (set = 0, binding = 0) uniform Matrices {
 layout (set = 0, binding = 1) uniform sampler2D tex;     
 
 void main() {
-	FragColor = vec4(1.0);
+	vec3 light_pos = normalize(vec3(cos(time), sin(time), 0.0))*10.0;
+	vec3 L = normalize(light_pos-pos);
+	float r = length(light_pos-pos);
+	float t = clamp(dot(L, norm), 0.0, 1.0) * 20.0/(r*r);
+
+	FragColor = vec4(vec3(t * 0.8) + vec3(0.2, 0.0, 0.1), 1.0);
 }
\ No newline at end of file
diff --git a/assets/shaders/terrain.frag.spv b/assets/shaders/terrain.frag.spv
index 13e9814..ee0651b 100644
Binary files a/assets/shaders/terrain.frag.spv and b/assets/shaders/terrain.frag.spv differ
diff --git a/assets/shaders/terrain.tese b/assets/shaders/terrain.tese
index 614c8b3..3d4813f 100644
--- a/assets/shaders/terrain.tese
+++ b/assets/shaders/terrain.tese
@@ -23,6 +23,7 @@ layout (location = 0) out vec3 _norm;
 layout (location = 1) out vec2 _texCoord;
 layout (location = 2) out vec3 _pos;
 
+
 void main() {
 	/* interpolation of UV coordinates */
 	vec2 uv1 = mix(texCoord[0], texCoord[1], gl_TessCoord.x);
@@ -39,7 +40,7 @@ void main() {
 	vec4 pos2 = mix(gl_in[3].gl_Position, gl_in[2].gl_Position, gl_TessCoord.x);
 
 	vec4 fpos = mix(pos1, pos2, gl_TessCoord.y);
-	fpos.y += 5.0 * textureLod(heightmap, _texCoord, 0.0).r;
+	fpos.y += 5.0 * textureLod(heightmap, _texCoord, 0.0).r + cos(fpos.x*fpos.y);
 
 	_pos = fpos.xyz;
 	gl_Position = proj * view * fpos;
diff --git a/assets/shaders/terrain.tese.spv b/assets/shaders/terrain.tese.spv
index 2c6ff04..12f4f3c 100644
Binary files a/assets/shaders/terrain.tese.spv and b/assets/shaders/terrain.tese.spv differ