diff --git a/src/renderer.js b/src/renderer.js
index 5f7a92cf..7dc193f8 100644
--- a/src/renderer.js
+++ b/src/renderer.js
@@ -436,6 +436,9 @@ class gltfRenderer
         case(DebugOutput.WORLDSPACENORMAL):
             fragDefines.push("DEBUG_WORLDSPACE_NORMAL 1");
             break;
+        case(DebugOutput.GEOMETRYNORMAL):
+            fragDefines.push("DEBUG_GEOMETRY_NORMAL 1");
+            break;
         case(DebugOutput.TANGENT):
             fragDefines.push("DEBUG_TANGENT 1");
             break;
diff --git a/src/rendering_parameters.js b/src/rendering_parameters.js
index 904926e5..e47c3e1e 100644
--- a/src/rendering_parameters.js
+++ b/src/rendering_parameters.js
@@ -50,6 +50,7 @@ const DebugOutput =
     ROUGHNESS: "Roughness",
     NORMAL: "Normal",
     WORLDSPACENORMAL: "Worldspace Normal",
+    GEOMETRYNORMAL: "Geometry Normal",
     TANGENT: "Tangent",
     BITANGENT: "Bitangent",
     BASECOLOR: "Base Color",
diff --git a/src/shaders/pbr.frag b/src/shaders/pbr.frag
index 001220c3..c114f9fe 100644
--- a/src/shaders/pbr.frag
+++ b/src/shaders/pbr.frag
@@ -124,10 +124,12 @@ NormalInfo getNormalInfo(vec3 v)
     #endif
 
     // For a back-facing surface, the tangential basis vectors are negated.
-    float facing = step(0.0, dot(v, ng)) * 2.0 - 1.0;
-    t *= facing;
-    b *= facing;
-    ng *= facing;
+    if (gl_FrontFacing == false)
+    {
+        t *= -1.0;
+        b *= -1.0;
+        ng *= -1.0;
+    }
 
     // Compute pertubed normals:
     #ifdef HAS_NORMAL_MAP
@@ -330,6 +332,13 @@ void main()
     #endif
 #endif
 
+    float ao = 1.0;
+    // Apply optional PBR terms for additional (optional) shading
+#ifdef HAS_OCCLUSION_MAP
+    ao = texture(u_OcclusionSampler,  getOcclusionUV()).r;
+    f_diffuse = mix(f_diffuse, f_diffuse * ao, u_OcclusionStrength);
+#endif
+
 #ifdef USE_PUNCTUAL
     for (int i = 0; i < LIGHT_COUNT; ++i)
     {
@@ -406,13 +415,6 @@ void main()
 
     color = (f_emissive + f_diffuse + f_specular + (1.0 - reflectance) * f_sheen) * (1.0 - clearcoatFactor * clearcoatFresnel) + f_clearcoat * clearcoatFactor;
 
-    float ao = 1.0;
-    // Apply optional PBR terms for additional (optional) shading
-#ifdef HAS_OCCLUSION_MAP
-    ao = texture(u_OcclusionSampler,  getOcclusionUV()).r;
-    color = mix(color, color * ao, u_OcclusionStrength);
-#endif
-
 #ifndef DEBUG_OUTPUT // no debug
 
 #ifdef ALPHAMODE_MASK
@@ -445,8 +447,12 @@ void main()
         #endif
     #endif
 
+    #ifdef DEBUG_GEOMETRY_NORMAL
+        g_finalColor.rgb = (normalInfo.ng + 1.0) / 2.0;
+    #endif
+
     #ifdef DEBUG_WORLDSPACE_NORMAL
-            g_finalColor.rgb = (n + 1.0) / 2.0;
+        g_finalColor.rgb = (n + 1.0) / 2.0;
     #endif
 
     #ifdef DEBUG_TANGENT