docs: Reorganize 3D.md and integrate tasks

- Moved 3D.md into the doc/ directory to centralize documentation.
- Updated README.md to reflect the new location of 3D.md.
- Captured the action items from 3D.md (visual debug mode, Blender exporter) and added them as a new task (#18) in the PROJECT_CONTEXT.md roadmap.

3 files changed, 4 insertions, 0 deletions

diff --git a/PROJECT_CONTEXT.md b/PROJECT_CONTEXT.md
index d21d5d5..ee22a89 100644
--- a/PROJECT_CONTEXT.md
+++ b/PROJECT_CONTEXT.md
@@ -35,6 +35,9 @@ Style:
 - **Task #5: Implement Spectrogram Editor**
     - [ ] Develop a web-based tool (`tools/editor`) for creating and editing `.spec` files visually.
     - [ ] The tool should support generating `.spec` files from elementary shapes (lines, curves) for extreme compression.
+- **Task #18: 3D System Enhancements**
+    - [ ] **Visual Debug Mode**: Implement a debug overlay (removable with `STRIP_ALL`) to render wireframe bounding volumes, object trajectories, and light source representations.
+    - [ ] **Blender Exporter**: Create a tool to convert simple Blender scenes into the demo's internal asset format.
 - **Phase 2: Advanced Size Optimization**
     - [x] PC+Windows (.exe binary) via MinGW
     - [ ] Task #4a: Linux Cross-Compilation
diff --git a/README.md b/README.md
index bfeaf6f..bd11057 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,7 @@ This is a C++ project aiming to create a cross-platform (Windows, macOS, Linux)
 - `PROCEDURAL.md`: Details on the procedural texture generation system.
 - `PROJECT_CONTEXT.md`: A comprehensive overview of the project's architecture, features, and current state.
 - `SPEC_EDITOR.md`: Plans for a future web-based spectrogram editor tool.
+- `3D.md`: Overview of the 3D rendering pipeline and future enhancements.
 - `TODO.md`: A list of immediate, small-scale tasks.
 
 ## Source Code Layout
diff --git a/3D.md b/doc/3D.md
index e944cbe..e944cbe 100644
--- a/3D.md
+++ b/doc/3D.md