Update instructions for Vulkan + macOS. (#5693)

BUILDING.md

@@ -144,6 +144,9 @@ make sure the command line tools are setup by running:
 $ xcode-select --install
 ```
 
+If you wish to run the Vulkan backend instead of the default Metal backend, you must install
+the LunarG SDK, enable "System Global Components", and reboot your machine.
+
 Then run `cmake` and `ninja` to trigger a build:
 
 ```

filament/README.md

@@ -44,10 +44,8 @@ To link against debug builds of Filament, you must also link against:
 
 - `matdbg`, Support library that adds an interactive web-based debugger to Filament
 
-To use the Vulkan backend on macOS you must also make the following libraries available at runtime:
-- `MoltenVK_icd.json`
-- `libMoltenVK.dylib`
-- `libvulkan.1.dylib`
+To use the Vulkan backend on macOS you must install the LunarG SDK, enable "System Global
+Components", and reboot your machine.
 
 The easiest way to install those files is to use the macOS
 [LunarG Vulkan SDK](https://www.lunarg.com/vulkan-sdk/) installer.

filament/docs/Debugging.md

@@ -1,19 +1,14 @@
 # Filament Debugging
 
-## Debugging Vulkan on macOS
-
-Install the LunarG SDK and allow the installer to include "System Global Components", which should
-be enabled by default.
-
 ## Debugging Vulkan on Linux
 
 ### Enable Validation Logs
 
 Simply install the LunarG SDK (it's fast and easy), then make sure you've got the following
-environment variables set up in your **bashrc** file:
+environment variables set up in your **bashrc** file. For example:
 
 ```
-export VULKAN_SDK='/usr/local/google/home/MY_LDAP/VulkanSDK/1.1.70.1/x86_64'
+export VULKAN_SDK='/path_to_home/VulkanSDK/1.3.216.0/x86_64'
 export VK_LAYER_PATH="$VULKAN_SDK/etc/explicit_layer.d"
 export PATH="$VULKAN_SDK/bin:$PATH"
 ```