Fix: CharacterController Slows Going Uphill

Player walks up 30° slope. Visible slowdown. Move vector wasn’t aligned to surface.

The Fix

void Update() {
    if (Physics.Raycast(transform.position, Vector3.down, out var hit, 1.1f)) {
        Vector3 input = new(inputX, 0, inputZ);
        Vector3 projected = Vector3.ProjectOnPlane(input, hit.normal).normalized * speed;
        controller.Move((projected + Vector3.up * gravityY) * Time.deltaTime);
    }
}

ProjectOnPlane keeps motion magnitude consistent across slopes. Combined with gravity for falling.

Verifying

Walk up 30° slope: same speed as flat. Without projection: visibly slower.

“Project on slope. Speed holds.”

Related Issues

For step edge snag, see step snag. For 2D slope, see 2D slope.

Project. Speed steady.