Dedicated server: bake no block models, which only the renderer draws

Co-Authored-By: Claude Opus 5.5 <[email protected]>

crates/horizon-client-render/src/assets.rs

@@ -192,8 +192,9 @@ impl Assets {
     pub fn reload(&self, root: &Path) -> Result<RenderAssets> {
         RenderAssets::load(root, self)
     }
-    /// [`Assets::reload`] for a server, which draws nothing: the models and
-    /// the sprites' layers, without the textures' pixels.
+    /// [`Assets::reload`] for a server, which draws nothing: the item models
+    /// and the sprites' layers, without the block models or the textures'
+    /// pixels.
     pub fn reload_for_server(&self, root: &Path) -> Result<RenderAssets> {
         RenderAssets::load_with(root, self, false)
     }
@@ -202,14 +203,19 @@ impl RenderAssets {
     pub fn load(root: &Path, assets: &Assets) -> Result<Self> {
         Self::load_with(root, assets, true)
     }
-    fn load_with(root: &Path, assets: &Assets, pixels: bool) -> Result<Self> {
+    fn load_with(root: &Path, assets: &Assets, draws: bool) -> Result<Self> {
         let registry = assets.registry;
         let mut sprites = crate::sprites::Sprites::with_disk_cache(root);
         for name in MATERIALS {
             sprites.insert(root, &format!("minecraft:block/{name}"))?;
         }
         let parsed = crate::model_library::ParsedModels::load(root);
-        let models = crate::models::prepare_with_models(root, registry, &mut sprites, &parsed)?;
+        // A server draws no block: its models (about 24 MB baked) stay empty.
+        let models = if draws {
+            crate::models::prepare_with_models(root, registry, &mut sprites, &parsed)?
+        } else {
+            crate::models::PreparedModels::default()
+        };
         let model_library = parsed.into_item_library();
         // Fluids are drawn by the fluid renderer, not block models; breaking
         // progress uses the destroy-stage overlays.
@@ -226,7 +232,7 @@ impl RenderAssets {
             sprites.insert(root, &format!("minecraft:block/destroy_stage_{stage}"))?;
         }
         sprites.save_disk_cache();
-        if pixels {
+        if draws {
             sprites.finish();
         } else {
             sprites.finish_without_pixels();

crates/horizon-client-render/src/models.rs

@@ -45,6 +45,7 @@ pub struct ModelInstance {
     pub layer: u32,
     pub shade: f32,
 }
+#[derive(Default)]
 pub struct PreparedModels {
     pub catalog: StateModels,
     pub placements: Vec<(BlockPos, BlockStateId)>,

crates/horizon-client-render/src/models/catalog.rs

@@ -42,6 +42,9 @@ pub struct BakedModel {
     pub cube: Option<[super::cube::CubeStyle; 6]>,
 }
 type VariantKey = (String, [u8; 3], bool);
+/// Empty by default: no state has a model (a dedicated server, which draws
+/// nothing).
+#[derive(Default)]
 pub struct StateModels {
     /// Each definition's choices, a variant standing as its index in `baked`.
     choices: Vec<CompiledChoices<u32>>,