feat: implement gltf loader

src/common/mesh.rs

@@ -81,7 +81,7 @@ impl MeshRegistry {
             let obj_num_idx = obj.indices.len();
             buf_indices.extend(obj.indices);
 
-            println!("Loaded mesh {} with {} vertices and {} indices", id, obj_num_verts, obj_num_idx);
+            println!("Loaded mesh \"{}\" with {} vertices and {} indices", id, obj_num_verts, obj_num_idx);
 
             // TODO Create bounding boxes for each mesh and associate them with the struct.
             mesh_list.insert(

src/common/render_batch.rs

@@ -21,7 +21,7 @@ impl RenderBatch {
         instance_registry: Arc<InstanceRegistry>
     ) -> Vec<Self> {
         mesh_registry.meshes.iter()
-            .map(|(id, mesh)| {
+            .filter_map(|(id, mesh)| {
                 let instances = instance_registry.get_instances_for(id);
 
                 let gpu_instances = instances.iter()
@@ -31,6 +31,10 @@ impl RenderBatch {
                     })
                     .collect::<Vec<GpuInstance>>();
 
+                if gpu_instances.is_empty() {
+                    return None;
+                }
+
                 // Build instances into a RenderBatch
                 let instance_buffer = Buffer::from_iter(
                     allocator.clone(),
@@ -46,11 +50,11 @@ impl RenderBatch {
                     gpu_instances
                 ).expect("Couldn't allocate instance buffer");
 
-                Self {
+                Some(Self {
                     mesh_id: id.clone(),
                     instance_buffer,
                     instance_count: instances.len() as u32,
-                }
+                })
             }).collect()
     }
 }