Split out the compatibility classes from the filament renderer.

The filament library provides APIs for creating the low-level
objects such as meshes and textures. The compat library provides
the high-level compatibility layer between mjvScene and the core
library.

PiperOrigin-RevId: 904504900
Change-Id: Ida1aecab4b9a8aefbbf6b0a0c4ba7ff164864b8e

src/experimental/filament/compat/scene_geom_util.h

@@ -0,0 +1,34 @@
+// Copyright 2025 DeepMind Technologies Limited
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MUJOCO_SRC_EXPERIMENTAL_FILAMENT_COMPAT_SCENE_GEOM_UTIL_H_
+#define MUJOCO_SRC_EXPERIMENTAL_FILAMENT_COMPAT_SCENE_GEOM_UTIL_H_
+
+#include <memory>
+
+#include <mujoco/mjvisualize.h>
+#include "experimental/filament/compat/model_objects.h"
+#include "experimental/filament/filament/object_manager.h"
+#include "experimental/filament/filament/renderable.h"
+
+namespace mujoco {
+
+// Creates a Renderable from the given mjvGeom.
+std::unique_ptr<Renderable> CreateGeomRenderable(
+    const mjvGeom& geom, const mjvScene* scene, ObjectManager* object_mgr,
+    ModelObjects* model_objs, const float headpos[3]);
+
+}  // namespace mujoco
+
+#endif  // MUJOCO_SRC_EXPERIMENTAL_FILAMENT_COMPAT_SCENE_GEOM_UTIL_H_