Fixed a crash in the PBR shader when adding a light map.

jme3-core/src/main/resources/Common/MatDefs/Light/PBRLighting.frag

@@ -148,6 +148,16 @@ void main(){
       vec3 normal = normalize(wNormal);            
     #endif
 
+    float specular = 0.5;
+    #ifdef SPECGLOSSPIPELINE
+          vec4 specularColor = texture2D(m_SpecularMap, newTexCoord);
+          vec4 diffuseColor = albedo;
+          Roughness = 1.0 - texture2D(m_GlossMap, newTexCoord).r;          
+    #else      
+        float nonMetalSpec = 0.08 * specular;
+        vec4 specularColor = (nonMetalSpec - nonMetalSpec * Metallic) + albedo * Metallic;
+        vec4 diffuseColor = albedo - albedo * Metallic;
+    #endif
 
     #ifdef LIGHTMAP
        vec3 lightMapColor;
@@ -160,17 +170,6 @@ void main(){
        albedo.rgb  *= lightMapColor;
     #endif
 
-    float specular = 0.5;
-    #ifdef SPECGLOSSPIPELINE
-          vec4 specularColor = texture2D(m_SpecularMap, newTexCoord);
-          vec4 diffuseColor = albedo;
-          Roughness = 1.0 - texture2D(m_GlossMap, newTexCoord).r;          
-    #else      
-        float nonMetalSpec = 0.08 * specular;
-        vec4 specularColor = (nonMetalSpec - nonMetalSpec * Metallic) + albedo * Metallic;
-        vec4 diffuseColor = albedo - albedo * Metallic;
-    #endif
-
     gl_FragColor.rgb = vec3(0.0);
     float ndotv = max( dot( normal, viewDir ),0.0);
     for( int i = 0;i < NB_LIGHTS; i+=3){