# 2026-01-28 - Documentation Update for Relative Rendering

## Changes Made

Updated rendering documentation to accurately reflect the actual implementation of the relative rendering system. The original planning document (`docs/planning/local_rendering_frame.md`) described a dual-frame local rendering system that was not implemented. The actual solution was simpler: relative rendering with linear scaling and child indicators.

## Commits

1. `2b68e2e` - Update rendering documentation to reflect relative rendering implementation

## Documentation Updates

### `docs/rendering.md` (+46 lines, updated)

**Updated sections:**
- **Overview**: Changed from "logarithmic distance scaling" to "linear distance scaling, relative rendering with child indicators"
- **RenderState struct**:
  - Removed: `previous_selected_body`, `was_following_body`
  - Added: `last_target_index`, `camera_target_enabled`
- **Scaling Factors**:
  - Changed from logarithmic scaling with separate size scale (0.02)
  - To linear scaling with unified distance/size scale (1e-9 for both)
  - Removed `scale_radius()` log10 formula
- **Camera System**: Added documentation for `get_initial_camera_distance()` function
- **Child Indicators**: New section added:
  - NASA Eyes-style hollow circles (20px radius, 2px thickness)
  - Text label centered inside
  - White for bodies, cyan for spacecraft
  - Only shown when body selected
  - Uses `GetWorldToScreen()` after `EndMode3D()`
- **Relative Rendering**: New section added:
  - Body selected: body at origin, children relative, full float precision
  - Spacecraft selected: parent relative to spacecraft, no siblings
  - Benefits: improved visibility, better precision, auto camera positioning
- **Render Order**: Added child indicators at position 6
- **Module Functions**: Added `get_initial_camera_distance()` to Camera section
- **TODO Items**: Added 2 items from planning doc:
  1. Distant Bodies (indicators for non-children)
  2. Smooth Frame Transitions (interpolation)

### `docs/planning/local_rendering_frame.md` (deleted, -596 lines)

Removed the original planning document as it described an unimplemented dual-frame system. Relevant TODO items were preserved in rendering.md.

## Net Line Count

**Total changes: +46, -610 lines**

## Remaining Issues

None. Documentation now accurately reflects the actual implementation.

## Next Steps

Ready to merge `render-fix` branch back to `main`.

## Technical Reference Update

The `docs/technical_reference.md` file does not need updates - it correctly references `docs/rendering.md` for complete rendering documentation and does not contain conflicting information.