Added print bed models for mk2 and mk3 printers to 3D scene

src/libslic3r/Technologies.hpp

@@ -42,8 +42,10 @@
 //====================
 #define ENABLE_1_42_0_ALPHA2 1
 
+// Improves navigation between sidebar fields
 #define ENABLE_IMPROVED_SIDEBAR_OBJECTS_MANIPULATION (1 && ENABLE_1_42_0_ALPHA2)
-
+// Adds print bed models to 3D scene
+#define ENABLE_PRINT_BED_MODELS (1 && ENABLE_1_42_0_ALPHA2)
 #endif // _technologies_h_