feat: add scene graph with spatial indexing and object placement

[ViTeXFTW]

Summary

This PR introduces a complete scene graph system with spatial indexing capabilities, along with utilities for object placement and resolution. The implementation provides efficient spatial queries for rendering and includes comprehensive test coverage.

Key Changes

Scene Graph Infrastructure

• SceneNode: Base class for all scene objects with transform (position, rotation, scale), visibility, and bounding box support
• SceneGraph: Container managing scene nodes with quadtree-based spatial indexing for efficient frustum and region queries
• Quadtree: Spatial partitioning data structure supporting:
  • Recursive subdivision with configurable depth and node capacity
  • Rectangular region queries
  • Frustum-based visibility queries
  • Automatic node placement based on world bounds

Object Placement & Resolution

• ObjectResolver: Caches and resolves W3D model files from template names using asset registry and archive manager
• ObjectNode: Scene node subclass wrapping HLodModel with skeleton pose support for animated objects
• ObjectPlacementUtils: Static utility functions for:
  • Template name to W3D filename conversion
  • Map coordinate to Vulkan coordinate transformation
  • Road/bridge point and render flag detection

Testing

• Comprehensive unit tests for SceneNode (transforms, bounds, visibility)
• Quadtree tests covering insertion, queries, and spatial operations
• SceneGraph tests for node management and visibility filtering
• ObjectPlacementUtils tests for coordinate conversion and flag detection

Implementation Details

• Quadtree uses center-point containment check first, then fallback to intersection for entries spanning multiple quadrants
• World bounds calculation transforms all 8 corners of local bounding box through world matrix
• Scene nodes without explicit bounds use 1-unit fallback bounds centered at position
• Frustum queries convert 2D rectangles to 3D bounding boxes with infinite Y range for intersection testing
• Model cache in ObjectResolver uses template name as key for efficient lookup

https://claude.ai/code/session_01JKxTAtdKkNECTCaiVV5Ywz

[ViTeXFTW]

@greptileai

[greptile-apps]

Greptile Summary

Implemented scene graph system with spatial indexing for efficient object placement and rendering queries. The PR adds a quadtree-based SceneGraph with SceneNode base class, ObjectNode for W3D models, and ObjectResolver for template-to-model caching.

Major Changes:

• SceneNode base class with position/rotation/scale transforms and world/local bounding boxes
• Quadtree spatial partitioning for rectangular and frustum-based queries
• SceneGraph container managing nodes with visibility filtering
• ObjectNode wrapping HLodModel with skeleton pose support
• ObjectResolver caching W3D models resolved from map template names
• ObjectPlacementUtils for coordinate conversion and flag detection
• Comprehensive test coverage for all scene graph components

Issues Found:

• Critical bug in quadtree.cpp:94 where depth parameter is hardcoded to 1 during subdivision, breaking depth tracking for multi-level trees
• Minor inconsistency between ObjectPlacementUtils::shouldRender() and MapObject::shouldRender() implementations

Confidence Score: 3/5

• Contains a depth tracking bug in quadtree subdivision that could cause incorrect spatial indexing behavior
• The quadtree subdivision bug at line 94 is a logical error that will cause incorrect depth tracking when nodes subdivide beyond depth 1. This could lead to excessive subdivision or failure to subdivide when expected, potentially affecting rendering performance and correctness. The rest of the implementation is solid with good test coverage.
• src/lib/scene/quadtree.cpp requires fixing the depth parameter bug in the subdivide function

Important Files Changed

Filename	Overview
src/lib/scene/scene_node.cpp	Added base SceneNode class with position, rotation, scale transforms and bounding box calculations - clean implementation
src/lib/scene/quadtree.cpp	Quadtree spatial indexing with potential depth tracking bug in subdivide function
src/lib/scene/scene_graph.cpp	SceneGraph container managing nodes with quadtree-based visibility queries - straightforward implementation
src/render/object_placement_utils.cpp	Utility functions for template name parsing and coordinate conversion - has inconsistency with MapObject::shouldRender
src/render/object_resolver.cpp	Model caching and W3D file resolution from template names - correct implementation

_{Last reviewed commit: d741f30}

[greptile-apps]

_{17 files reviewed, 2 comments}

_{Edit Code Review Agent Settings | Greptile}

[ViTeXFTW]

@greptileai

[greptile-apps]

Greptile Summary

This PR implements a complete scene graph system with spatial indexing for efficient object management in the map viewer. The implementation addresses previous review feedback and maintains consistency across the codebase.

• Scene Graph Core: SceneNode base class provides transforms (position, Y-rotation, scale), bounding boxes, and visibility. SceneGraph manages nodes with quadtree-based spatial indexing for efficient frustum culling.
• Quadtree Spatial Indexing: Recursive subdivision with configurable depth/capacity, supporting both rectangular region and frustum-based queries. Previous depth tracking bug has been fixed.
• Object Placement: ObjectResolver caches W3D models by template name, loading from BIG archives. ObjectNode wraps HLodModel with skeleton pose support. ObjectPlacementUtils handles template name parsing and coordinate conversion (map Y/Z swap to Vulkan Y/Z).
• Render Filtering: shouldRender() logic now consistent between MapObject::shouldRender() and ObjectPlacementUtils::shouldRender() - both exclude FLAG_DONT_RENDER, road points, and bridge points.
• Test Coverage: Comprehensive unit tests cover scene nodes, quadtree operations (including depth tracking regression test), scene graph queries, and object placement utilities.

Confidence Score: 5/5

• This PR is safe to merge with no issues found
• All previous review feedback has been addressed, implementation follows project patterns, comprehensive test coverage validates correctness, and no bugs or inconsistencies were found
• No files require special attention

Important Files Changed

Filename	Overview
src/lib/scene/scene_node.cpp	Transform and bounding box computation - correctly transforms all 8 corners
src/lib/scene/quadtree.cpp	Quadtree implementation with correct depth tracking after addressing previous feedback
src/lib/scene/scene_graph.cpp	Scene graph implementation with visibility filtering for queries
src/render/object_placement_utils.cpp	Template name parsing, coordinate conversion, and render flag filtering - consistent with types.hpp
src/render/object_resolver.cpp	W3D model loading from BIG archives with template-based caching
src/lib/formats/map/types.hpp	Updated MapObject::shouldRender to exclude road/bridge points, now consistent with ObjectPlacementUtils

_{Last reviewed commit: f20af65}