Remove separate targets for classic and filament renderer.

The platform::Renderer now supports both implementations at
runtime.

PiperOrigin-RevId: 878427862
Change-Id: I2997c197c6eddbe177c77b435cc5848fd80f1839

CMakeLists.txt

@@ -47,7 +47,8 @@ if(NOT EMSCRIPTEN)
   option(MUJOCO_TEST_PYTHON_UTIL "Build and test utility libraries for Python bindings" ON)
   option(MUJOCO_WITH_USD "Build with OpenUSD" OFF)
   option(MUJOCO_USE_FILAMENT "Use filament rendering" OFF)
-  option(MUJOCO_USE_FILAMENT_VULKAN "Use vulkan backend for filament rendering" OFF)
+  # Allows filament renderer to be used with mjr API; disables src/render to prevent conflicts.
+  option(MUJOCO_USE_FILAMENT_MJR_COMPAT "Use filament mjr compatibility layer" OFF)
 endif()
 
 if(EMSCRIPTEN)
@@ -114,19 +115,15 @@ add_subdirectory(src/engine)
 add_subdirectory(src/user)
 add_subdirectory(src/xml)
 add_subdirectory(src/thread)
-
-if(MUJOCO_USE_FILAMENT AND NOT EMSCRIPTEN)
-  # Note that, by default, the "src/render" and "src/ui" code is added directly
-  # into the "mujoco" target. However, "mujoco::filament" is a separate,
-  # explicit target. Therefore, if you want to use MuJoCo with Filament, you
-  # will need to explicitly add the "mujoco::filament" target as a link
-  # dependency in your project.
-  add_subdirectory(src/experimental/filament)
-elseif(NOT EMSCRIPTEN)
+if(NOT EMSCRIPTEN AND NOT MUJOCO_USE_FILAMENT_MJR_COMPAT)
   add_subdirectory(src/render)
   add_subdirectory(src/ui)
 endif()
 
+if(MUJOCO_USE_FILAMENT AND NOT EMSCRIPTEN)
+  add_subdirectory(src/experimental/filament)
+endif()
+
 if(EMSCRIPTEN)
   add_subdirectory(wasm)
   if(MUJOCO_BUILD_TESTS_WASM)