Merge pull request #1697 from MackeyK24/master

Master

Exporters/3ds Max/BabylonExport.Entities/BabylonPBRMaterial.cs

@@ -119,10 +119,10 @@ namespace BabylonExport.Entities
         public float[] emissive { get; set; }
 
         [DataMember]
-        public float roughness { get; set; }
+        public float? roughness { get; set; }
 
         [DataMember]
-        public float metallic { get; set; }
+        public float? metallic { get; set; }
 
         [DataMember]
         public bool useRoughnessFromMetallicTextureAlpha { get; set; }
@@ -172,8 +172,9 @@ namespace BabylonExport.Entities
             cameraContrast = 1.0f;
             useEmissiveAsIllumination = false;
 
-            metallic = 0.0f;
-            roughness = 0.0f;
+            // Default Null Metallic Workflow
+            metallic = null;
+            roughness = null;
             useRoughnessFromMetallicTextureAlpha = false;
             useRoughnessFromMetallicTextureGreen = false;
 

src/Materials/babylon.pbrMaterial.ts

@@ -938,7 +938,7 @@
                 this._defines.RADIANCEOVERALPHA = true;
             }
 
-            if (this.metallic !== undefined || this.roughness !== undefined) {
+            if ((this.metallic !== undefined && this.metallic !== null) || (this.roughness !== undefined && this.roughness !== null)) {
                 this._defines.METALLICWORKFLOW = true;
             }