Small fixes to decor rendering.

Use an unlit material for decorative elements and do not render them
in the reflection pass.

PiperOrigin-RevId: 899560291
Change-Id: I3b035d556432c850ce8240e0c4c4c2d6645d7bf2

src/experimental/filament/CMakeLists.txt

@@ -114,6 +114,7 @@ set(MATERIAL_FILES
     phong_cube_fade.mat
     phong_cube.mat
     phong_cube_reflect.mat
+    unlit_decor.mat
     unlit_depth.mat
     unlit_line.mat
     unlit_segmentation.mat

src/experimental/filament/assets/unlit_decor.mat

@@ -0,0 +1,29 @@
+// 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.
+
+material {
+    name : unlit_decor,
+    shadingModel : unlit,
+    culling: none,
+    parameters : [
+        { type : float4, name : BaseColorFactor }
+    ]
+}
+
+fragment {
+    void material(inout MaterialInputs material) {
+      prepareMaterial(material);
+      material.baseColor = materialParams.BaseColorFactor;
+    }
+}

src/experimental/filament/filament/object_manager.cc

@@ -84,6 +84,7 @@ ObjectManager::ObjectManager(filament::Engine* engine)
   materials_[kPhongCubeReflect] = LoadMaterial("phong_cube_reflect.filamat");
   materials_[kUnlitSegmentation] = LoadMaterial("unlit_segmentation.filamat");
   materials_[kUnlitLine] = LoadMaterial("unlit_line.filamat");
+  materials_[kUnlitDecor] = LoadMaterial("unlit_decor.filamat");
   materials_[kUnlitDepth] = LoadMaterial("unlit_depth.filamat");
   materials_[kUnlitUi] = LoadMaterial("unlit_ui.filamat");
 

src/experimental/filament/filament/object_manager.h

@@ -49,6 +49,7 @@ class ObjectManager {
     kPhongCubeFade,
     kPhongCubeReflect,
     kUnlitSegmentation,
+    kUnlitDecor,
     kUnlitDepth,
     kUnlitLine,
     kUnlitUi,

src/experimental/filament/filament/renderable.cc

@@ -183,7 +183,8 @@ void Renderable::SetMaterialInstance(filament::MaterialInstance* instance) {
   }
 }
 
-void Renderable::SetLayerMask(std::uint8_t mask) {
+std::uint8_t Renderable::SetLayerMask(std::uint8_t mask) {
+  std::uint8_t prev = layer_mask_;
   if (mask != layer_mask_) {
     layer_mask_ = mask;
 
@@ -192,9 +193,11 @@ void Renderable::SetLayerMask(std::uint8_t mask) {
       rm.setLayerMask(rm.getInstance(entity), 0xff, layer_mask_);
     }
   }
+  return prev;
 }
 
-void Renderable::SetPriority(std::uint8_t priority) {
+std::uint8_t Renderable::SetPriority(std::uint8_t priority) {
+  std::uint8_t prev = priority_;
   if (priority != priority_) {
     priority_ = priority;
 
@@ -203,6 +206,7 @@ void Renderable::SetPriority(std::uint8_t priority) {
       rm.setPriority(rm.getInstance(entity), priority_);
     }
   }
+  return prev;
 }
 
 void Renderable::SetCastShadows(bool cast_shadows) {

src/experimental/filament/filament/renderable.h

@@ -57,10 +57,10 @@ class Renderable {
   int GetNumEntities() const { return entities_.size(); }
 
   // Hides all managed entities.
-  void SetLayerMask(std::uint8_t mask);
+  std::uint8_t SetLayerMask(std::uint8_t mask);
 
   // Sets the priority of all managed entities.
-  void SetPriority(std::uint8_t priority);
+  std::uint8_t SetPriority(std::uint8_t priority);
 
   // Disables the renderables from casting shadows.
   void SetCastShadows(bool cast_shadows);

src/experimental/filament/filament/scene_geom_util.cc

@@ -206,6 +206,7 @@ static void SetGeomTransform(Renderable& renderable, const mjvGeom& geom) {
   }
 
   mat4 transform = mat4(ReadMat3(geom.mat), ReadFloat3(geom.pos));
+  renderable.SetLayerMask(geom.category);
 
   float3 size = ReadFloat3(geom.size);
   filament::TransformManager& tm =
@@ -362,6 +363,8 @@ static void UpdateGeomMaterial(Renderable& renderable, const mjvGeom& geom,
   ObjectManager::MaterialType material_type = ObjectManager::kNumMaterials;
   if (geom.type == mjGEOM_LINE || geom.type == mjGEOM_LINEBOX) {
     material_type = ObjectManager::kUnlitLine;
+  } else if (geom.category == mjCAT_DECOR) {
+    material_type = ObjectManager::kUnlitSegmentation;
   } else {
     bool material_assigned = false;
     if (geom.matid >= 0) {

src/experimental/filament/filament/scene_view.cc

@@ -17,6 +17,7 @@
 #include <algorithm>
 #include <array>
 #include <cstddef>
+#include <cstdint>
 #include <memory>
 
 #include <filament/ColorGrading.h>
@@ -135,6 +136,7 @@ SceneView::SceneView(filament::Engine* engine) : engine_(engine) {
     view = engine->createView();
     view->setScene(scene_);
     view->setCamera(camera_);
+    view->setVisibleLayers(0xff, mjCAT_ALL);
   }
 
   reflect_view_ = engine->createView();
@@ -142,6 +144,7 @@ SceneView::SceneView(filament::Engine* engine) : engine_(engine) {
   reflect_view_->setCamera(reflect_camera_);
   reflect_view_->setShadowingEnabled(false);
   reflect_view_->setPostProcessingEnabled(false);
+  reflect_view_->setVisibleLayers(0xff, mjCAT_DYNAMIC | mjCAT_STATIC);
 
   // Disable post processing for the depth and segmentation views to preserve
   // the values.
@@ -260,7 +263,7 @@ void SceneView::Render(filament::Renderer* renderer,
       SetupReflectionCamera(transform, camera_, reflect_camera_);
 
       // Hide reflective surface from its own reflection pass.
-      renderable->SetLayerMask(0x00);
+      std::uint8_t previous_layer_mask = renderable->SetLayerMask(0x00);
 
       // Render the reflection to its render target.
       reflect_view_->setRenderTarget(
@@ -268,7 +271,7 @@ void SceneView::Render(filament::Renderer* renderer,
       renderer->render(reflect_view_);
 
       // Unhide the reflective surface.
-      renderable->SetLayerMask(0x01);
+      renderable->SetLayerMask(previous_layer_mask);
     }
   }