Function spawnPrefabEntity

src/world/loader.ts:222–280

(
  entity: EntityData,
  ctx: InstantiateContext,
  warnings: string[],
)

}

function spawnPrefabEntity(
  entity: EntityData,
  ctx: InstantiateContext,
  warnings: string[],
): SceneNodeHandle {
  if (!ctx.prefabRegistry) {
    warnings.push(
      'entity ' + entity.id + ' references prefab "' + entity.prefabRef + '" but no PrefabRegistry was provided — skipped',
    );
    return 0;
  }

  // Create a root group node at the entity's transform. Expanded leaves are
  // parented to this root so the editor gizmo can move the whole prefab as
  // one unit.
  const root = createSceneNode();
  const rootMatrix = trsToMat4(entity.transform);
  setSceneNodeTransform(root, rootMatrix);
  setSceneNodeVisible(root, true);

  // Expand the prefab into its leaf glbs and spawn one scene node per leaf.
  // `expandPrefab` accumulates leaves into `leaves` and any errors into a
  // local list which we fold into the top-level warnings.
  const leaves: PrefabLeaf[] = [];
  const expandErrors: string[] = [];
  const visited = new Set<string>();
  expandPrefab(
    ctx.prefabRegistry,
    entity.prefabRef as string,
    mat4Identity(),
    entity.tint,
    entity.tags,
    leaves,
    expandErrors,
    visited,
    'world.entities[' + entity.id + ']',
  );

  for (let i = 0; i < expandErrors.length; i++) warnings.push(expandErrors[i]);

  for (let i = 0; i < leaves.length; i++) {
    const leaf = leaves[i];
    const modelHandle = ctx.getModelHandle(leaf.modelRef);
    if (modelHandle === 0) {
      warnings.push(
        'prefab leaf ' + leaf.sourcePath + ' references unknown model "' + leaf.modelRef + '" — skipped',
      );
      continue;
    }
    const leafNode = createSceneNode();
    attachModelToNode(leafNode, modelHandle, 0);
    setSceneNodeTransform(leafNode, leaf.worldMatrix);
    if (leaf.tint !== null) applyTint(leafNode, leaf.tint);
    setSceneNodeParent(leafNode, root);
    setSceneNodeVisible(leafNode, true);
  }

  return root;