Change item model alpha tests to match values used for rendering (#4490)

src/main/java/net/minecraftforge/client/model/ItemLayerModel.java

@@ -142,7 +142,7 @@ public final class ItemLayerModel implements IModel
                 for(int u = 0; u < uMax; u++)
                 {
                     int alpha = getAlpha(pixels, uMax, vMax, u, v);
-                    boolean t = alpha == 0;
+                    boolean t = alpha / 255f <= 0.1f;
 
                     if (!t && alpha < 255)
                     {

src/main/java/net/minecraftforge/client/model/ItemTextureQuadConverter.java

@@ -206,10 +206,9 @@ public final class ItemTextureQuadConverter
         return quads;
     }
 
-    // true if alpha != 0
     private static boolean isVisible(int color)
     {
-        return (color >> 24 & 255) > 0;
+        return (color >> 24 & 255) / 255f > 0.1f;
     }
 
     /**