Bug: r_dot_e was incorrectly divided by mu instead of r_mag*e_mag,
causing cos_nu values of ~7.5e6 (far outside [-1,1]) which made acos() return NaN.
Fix: Calculate cos_nu correctly as r_dot_e/(r_mag*e_mag) and clamp
to [-1, 1] to handle floating-point precision errors.
This fixes all cartesian <-> orbital elements round-trip conversion tests.
Added 6 test files for Newton-Raphson solver and analytical propagation:
- test_cartesian_to_elements_basic.cpp: Tests state vector ↔ orbital elements conversion
- test_newton_raphson_convergence.cpp: Tests Newton-Raphson solver convergence behavior
- test_analytical_propagation_apsides.cpp: Tests propagation through orbital apsides
- test_analytical_propagation_timesteps.cpp: Tests propagation with various timesteps
- test_extreme_eccentricity.cpp: Tests near-parabolic and hyperbolic orbits
- test_precision_boundaries.cpp: Tests exact boundary value handling
Implemented core orbital mechanics functions:
- solve_kepler_equation(): Newton-Raphson solver with 1e-10 tolerance
- get_initial_trial_value(): Series expansion initial guess
- cartesian_to_orbital_elements(): State vectors to orbital elements conversion
- propagate_orbital_elements(): Analytical propagation using Kepler's equation
Updated test plan document with current progress and remaining tests.
Test status: 66 passed, 14 failed (out of 80 test cases)
- Failing tests are expected: implementation needs debugging
- Config validation issues fixed by adjusting orbital parameters
- Add StabilityResult struct to capture per-body results
- Add print_summary() function that displays formatted test results
- Summary includes:
- Stability criteria explanation
- Per-body results table with stability status
- Overall analysis with recommendations
- Current time step assessment
- Status shows current dt=60s is very stable with good margin
- Can be increased significantly if needed for faster simulation
- Create tests/informational/ for diagnostic/informational tests not in main suite
- Move test_time_step_stability.{cpp,toml} from tests/ to informational/
- Add README.md documenting informational tests purpose and usage
- Add dedicated Makefile for building informational tests separately
- Tests find maximum stable time step for RK4 integration across different orbital regimes
- Limiting factor is Mercury orbiter (12h period): max stable dt = 270s
- Current default 60s is very stable with good margin
- Remove unconditional reset of ui_state.selected_craft_index in render_body_list_ui()
- Only reset ui_state.selected_craft_index to -1 when body is selected
- This prevents panel from disappearing in subsequent frames when spacecraft remains selected
- Ensure camera is always at least INITIAL_DISTANCE_RADIUS_MULTIPLIER (100x) away from target body's radius
- get_initial_camera_distance() returns max(average_children_distance, body_radius * 100) when children exist
- get_initial_camera_distance() returns body_radius * 100 when no children
- Prevents camera clipping when switching from Sun (large radius) to Earth (small radius) with close children
- Remove selected_craft_index from RenderState, move to UIState
- Camera now always targets bodies (directly selected or parent of selected spacecraft)
- UI handles all spacecraft selection logic
- Remove ~30 lines of duplicate/special-case code from renderer
- Update all renderer functions to single body-focused path
- Update UI rendering functions to use ui_state->selected_craft_index
- Add Mat3 struct documentation
- Update OrbitalElements note: 3D now fully implemented
- Document matrix operations in Physics module section
- Update OrbitTracker with new orbital element fields
- Remove deferred status from Orbital Mechanics documentation
- Add orbital element fields to OrbitTracker struct (inclination, RAAN, argument_of_periapsis)
- Create create_orbit_tracker_3d() for initializing with orbital elements
- Modify update_orbit_tracker() to use inverse rotation matrix for angle calculation
- Transform 3D position back to orbital plane before computing angle
- Update Molniya period test to use 3D tracker and relaxed tolerance (30 min)
- Remove remaining [!mayfail] tags
All 47 test cases now pass with 239,431 assertions
- Molniya position tests now pass with 3D rotation implementation
- Generic inclined orbit test passes with proper argument_of_periapsis
- Only orbital period test still fails (orbit tracker needs 3D fix)
- Add plan document for fixing update_orbit_tracker()
- Modify orbital_elements_to_cartesian() to apply z-x-z Euler rotations
- Apply rotation: R_z(Ω) · R_x(i) · R_z(ω) to position and velocity
- Fix generic inclined orbit test: set argument_of_periapsis to π/2
- Molniya position tests now pass with non-zero z-coordinates
- Period test still fails (orbit tracker doesn't handle 3D orbits yet)
- Remove altitude convenience parameter from body and spacecraft config parsing
- Update test configs to use explicit semi_major_axis instead of altitude
- Remove buggy post-processing loop that added parent radius to all spacecraft
- Result: Semi-major axis now used as-is (correct behavior)
- Test results: Molniya position tests now pass (was failing by 1-11M meters)
- Documentation: Remove altitude references from technical reference
- Planning: Document bug fix decision and implementation details
Changes:
- src/config_loader.cpp: Remove altitude parsing and post-processing
- tests/test_maneuver_planning.toml: Use semi_major_axis = 6.771e6
- tests/test_maneuvers.toml: Use semi_major_axis = 6.771e6
- tests/test_orbit_rendering.toml: Use semi_major_axis = 6.771e6
- docs/technical_reference.md: Remove altitude documentation
- docs/planning/molniya-orbit-test-plan.md: Document bug fix approach
- Create test configuration for Molniya orbits with Earth as root body
- Implement test suite for highly inclined orbits:
* Position verification at multiple true anomalies
* Orbital period verification
* Generic inclined orbit test
* Inclination parameter preservation
- Document critical bug in spacecraft initialization:
* Config loader incorrectly adds parent radius to semi_major_axis
* Affects all spacecraft using semi_major_axis directly
* Causes significant position errors (1-11M meters)
* Molniya tests fail due to this bug, not test code
- Change scale_radius() from logarithmic to linear scaling
- Add get_initial_camera_distance() for auto camera positioning
- Implement selected-body-relative rendering (body at origin)
- Add child indicators with hollow circles and text labels
- Restructure render_simulation() with conditional logic
- Fix zoom camera min_distance check for both directions
- Camera automatically positioned based on average child distance
