Fixed an issue with parallax mapping thanks to this thread http://hub.jmonkeyengine.org/forum/topic/parallax-mapping-fundamental-bug/#post-256898

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@10993 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/core-data/Common/MatDefs/Light/Lighting.frag

@@ -211,11 +211,14 @@ void main(){
     // ***********************
     #if defined(NORMALMAP) && !defined(VERTEX_LIGHTING)
       vec4 normalHeight = texture2D(m_NormalMap, newTexCoord);
-      vec3 normal = normalize((normalHeight.xyz * vec3(2.0) - vec3(1.0)));
+      //Note the -2.0 and -1.0. We invert the green channel of the normal map, 
+      //as it's complient with normal maps generated with blender.
+      //see http://hub.jmonkeyengine.org/forum/topic/parallax-mapping-fundamental-bug/#post-256898
+      //for more explanation.
+      vec3 normal = normalize((normalHeight.xyz * vec3(2.0,-2.0,2.0) - vec3(1.0,-1.0,1.0)));
       #ifdef LATC
         normal.z = sqrt(1.0 - (normal.x * normal.x) - (normal.y * normal.y));
       #endif      
-      //normal.y = -normal.y;
     #elif !defined(VERTEX_LIGHTING)
       vec3 normal = vNormal;
       #if !defined(LOW_QUALITY) && !defined(V_TANGENT)

engine/src/core-data/Common/MatDefs/Light/Lighting.vert

@@ -171,7 +171,7 @@ void main(){
      vec3 wvTangent = normalize(g_NormalMatrix * modelSpaceTan);
      vec3 wvBinormal = cross(wvNormal, wvTangent);
 
-     mat3 tbnMat = mat3(wvTangent, wvBinormal * -inTangent.w,wvNormal);
+     mat3 tbnMat = mat3(wvTangent, wvBinormal * inTangent.w,wvNormal);
      
      //vPosition = wvPosition * tbnMat;
      //vViewDir  = viewDir * tbnMat;