From fcd9a9c0ac5bcec4bfef3fa553607f19de914803 Mon Sep 17 00:00:00 2001
From: lukemckinstry <lukemckinstry@gmail.com>
Date: Wed, 15 Jan 2025 16:37:51 -0500
Subject: [PATCH] add tile visible event

---
 packages/engine/Source/Scene/VoxelPrimitive.js | 16 ++++++++++++++++
 packages/engine/Source/Scene/VoxelTraversal.js |  1 +
 2 files changed, 17 insertions(+)

diff --git a/packages/engine/Source/Scene/VoxelPrimitive.js b/packages/engine/Source/Scene/VoxelPrimitive.js
index ad825eaf598..54c9f529bf1 100644
--- a/packages/engine/Source/Scene/VoxelPrimitive.js
+++ b/packages/engine/Source/Scene/VoxelPrimitive.js
@@ -478,6 +478,22 @@ function VoxelPrimitive(options) {
    */
   this.tileLoad = new Event();
 
+  /**
+   * This event fires once for each visible tile in a frame.
+   * <p>
+   * This event is fired during the traversal while the frame is being rendered.
+   *
+   * @type {Event}
+   * @default new Event()
+   *
+   * @example
+   * tileset.tileVisible.addEventListener(function() {
+   *     console.log('A tile is visible.');
+   * });
+   *
+   */
+  this.tileVisible = new Event();
+
   /**
    * The event fired to indicate that a tile's content failed to load.
    * <p>
diff --git a/packages/engine/Source/Scene/VoxelTraversal.js b/packages/engine/Source/Scene/VoxelTraversal.js
index 6835e1811b7..91260dbf544 100644
--- a/packages/engine/Source/Scene/VoxelTraversal.js
+++ b/packages/engine/Source/Scene/VoxelTraversal.js
@@ -968,6 +968,7 @@ function generateOctree(that, sampleCount, levelBlendFactor) {
     } else {
       // Store the leaf node information instead
       // Recursion stops here because there are no renderable children
+      that._primitive.tileVisible.raiseEvent();
       if (useLeafNodes) {
         const baseIdx = leafNodeCount * 5;
         const keyframeNode = node.renderableKeyframeNodePrevious;