Prevent decorative elements from casting shadows.

PiperOrigin-RevId: 837112208
Change-Id: I4ecc110eec1a2166df7a07d8bb9ec37df36b7c89

src/experimental/filament/filament/drawable.cc

@@ -72,6 +72,10 @@ static constexpr int kArrow2BottomConeDisk = 4;
 Drawable::Drawable(ObjectManager* object_mgr, const mjvGeom& geom)
     : material_(object_mgr),
       renderables_(object_mgr->GetEngine()) {
+  if (geom.category == mjCAT_DECOR) {
+    renderables_.DisableShadows();
+  }
+
     switch ((mjtGeom)geom.type) {
     case mjGEOM_MESH:
       AddMesh(geom.dataid);

src/experimental/filament/filament/renderables.cc

@@ -103,7 +103,7 @@ utils::Entity Renderables::CreateEntity(const FilamentBuffers& buffers) {
   }
   builder.boundingBox(buffers.bounds)
       .culling(false)
-      .castShadows(true)
+      .castShadows(cast_shadows_)
       .receiveShadows(true)
       .layerMask(1, visible_ ? 1 : 0)
       .screenSpaceContactShadows(true);
@@ -197,4 +197,12 @@ void Renderables::Show() {
   }
 }
 
+void Renderables::DisableShadows() {
+  filament::RenderableManager& rm = engine_->getRenderableManager();
+  for (utils::Entity& entity : entities_) {
+    rm.setCastShadows(rm.getInstance(entity), false);
+  }
+  cast_shadows_ = false;
+}
+
 }  // namespace mujoco

src/experimental/filament/filament/renderables.h

@@ -61,6 +61,9 @@ class Renderables {
   // Returns true if the entities are visible.
   bool IsVisible() const { return visible_; }
 
+  // Disables the renderables from casting shadows.
+  void DisableShadows();
+
   // Adds all managed entities to the given filament Scene.
   void AddToScene(filament::Scene* scene);
 
@@ -84,6 +87,7 @@ class Renderables {
   std::vector<utils::Entity> entities_;
   std::vector<std::optional<FilamentBuffers>> owned_buffers_;
   bool visible_ = true;
+  bool cast_shadows_ = true;
 };
 
 }  // namespace mujoco