The original fix only applied 4D rotation to Q/E (ana/kata) movement. W/A/S/D movement was still projected to XZ plane only, stripping the W component even after 4D rotation. Now all movement directions (forward, right, ana) are projected to the XZW hyperplane, keeping their W components. This means: - After 4D rotation, W/S affects W coordinate (not just X/Z) - After 4D rotation, A/D affects W coordinate (not just X/Z) - After 4D rotation, Q/E affects X/Z coordinates (not just W) All movement now correctly rotates with the camera's 4D orientation. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>