Camera-Relative Vector Math Inspector (3D Three.js WebGL)

Transforming 2D Input (WASD) relative to Camera Orbit Yaw

CAMERA ORBIT YAW

Camera Yaw Angle: 45°

KEYBOARD INPUT (WASD)

C# VECTOR MATH DECONSTRUCTION

// 1. Read flattened camera basis vectors
Vector3 camFwd = cameraTransform.forward;
camFwd.y = 0f; camFwd.Normalize();
Vector3 camRight = cameraTransform.right;
camRight.y = 0f; camRight.Normalize();

// 2. Construct move vector from inputs (0, 1)
Vector3 move = (camFwd * 1f + camRight * 0f).normalized;
// Resulting World Vector: (0.71, 0.00, 0.71) at Cam Yaw 45°

LAB MODE STUDY GUIDE: DEEP DIVE

VECTOR MATHEMATICS

Mental Model:

When a player pushes the 'W' key, their intuitive expectation is "Move in the direction the camera is currently looking". Pushing 'D' means "Move right relative to the camera screen". To translate this into 3D world coordinates, we project the camera's forward and right basis vectors onto the horizontal XZ plane.

Why Flatten Y (camFwd.y = 0f):

Cameras in 3rd-person games tilt downward (pitch > 0). If you do not zero out camFwd.y, pressing 'W' tries to push the character diagonally down into the ground, losing speed to floor friction.

Diagonal Normalization:

Pressing 'W' and 'D' simultaneously gives an input vector of (1, 1) with magnitude 1.414. Calling .normalized clamps diagonal movement to 1.0, preventing diagonal speed exploiting.

# PlayerMovement3D • Camera Reference & Vector Pipeline

Inspector Configuration

Camera Transform MainCamera (Transform)

Move Speed / Sprint Multiplier 6.00 m/s / 1.50x

Rotation Smooth Time (Slerp) 0.10 s

Flatten Y Basis Vectors [X] True (camFwd.y = 0; camRight.y = 0)

Common Trap and Why It Breaks:

Transforming move vectors using transform.TransformDirection instead of the Camera's basis vectors. The character ends up moving relative to their own forward heading, making orbital camera navigation completely uncontrollable.

Golden Rule for Your Project: Always cache Camera.main.transform, zero out its Y component, normalize it, and construct world move vectors using camera-relative basis math.

HR Teacher Mode Access

Keyboard Shortcuts

Teacher Speaker Notes [N]