feat: Implement 3D system and procedural texture manager

- Extended mini_math.h with mat4 multiplication and affine transforms.
- Implemented TextureManager for runtime procedural texture generation and GPU upload.
- Added 3D system components: Camera, Object, Scene, and Renderer3D.
- Created test_3d_render mini-demo for interactive 3D verification.
- Fixed WebGPU validation errors regarding depthSlice and unimplemented WaitAny.

1 files changed, 22 insertions, 0 deletions

diff --git a/src/3d/scene.h b/src/3d/scene.h
new file mode 100644
index 0000000..6793975
--- /dev/null
+++ b/src/3d/scene.h
@@ -0,0 +1,22 @@
+// This file is part of the 64k demo project.
+// It defines the Scene container.
+// Manages a collection of objects and lights.
+
+#pragma once
+
+#include "3d/object.h"
+#include <vector>
+
+class Scene {
+ public:
+  std::vector<Object3D> objects;
+  // std::vector<Light> lights; // Future
+
+  void add_object(const Object3D& obj) {
+    objects.push_back(obj);
+  }
+
+  void clear() {
+    objects.clear();
+  }
+};