/**
 * Structure for a vector in 3D space.
 */
export declare class Vec3 {
    readonly x: number;
    readonly y: number;
    readonly z: number;
    /**
     * The magnitude/length of the vector
     */
    readonly r: number;
    /**
     * The angle of the vector in radians, measured from the x-axis
     */
    readonly theta: number;
    /**
     * The angle of the vector in radians, measured from the xy-plane
     */
    readonly phi: number;
    /**
     * Create a vector from cartesian coordinates
     * @param x The cartesian x-coordinate
     * @param y The cartesian y-coordinate
     * @param z The cartesian z-coordinate
     */
    constructor(x: number, y: number, z?: number);
    /**
     * Create a vector from polar coordinates
     * @param r The magnitude/length of the vector
     * @param theta The angle of the vector in radians, measured from the x-axis
     * @param phi The angle of the vector in radians, measured from the xy-plane
     * @returns A vector created from polar coordinates
     */
    static fromPolar(r: number, theta: number, phi?: number): Vec3;
    /**
     * Determine if two vectors are equal (or approximately equal)
     * @param other Arbitrary vector
     * @param tolerance Optional absolute tolerance
     * @returns `true` if v1 = v2
     */
    equals(other: Vec3, tolerance?: number): boolean;
    /**
     * Get a unit vector in this direction
     * @returns v1 (with length 1)
     */
    unit(): Vec3;
    /**
     * Scale this vector by a numeric factor
     * @param factor Scaling factor
     * @returns A scaled vector
     */
    scaleBy(factor: number): Vec3;
    /**
     * Add this vector and another vector
     * @param other Arbitrary vector
     * @returns v1 + v2
     */
    plus(other: Vec3): Vec3;
    /**
     * Subtract another vector from this vector
     * @param other Arbitrary vector
     * @returns v1 - v2
     */
    minus(other: Vec3): Vec3;
    /**
     * Compute the dot product between this vector and another vector
     * @param other Arbitrary vector
     * @returns v1 . v2
     */
    dot(other: Vec3): number;
    /**
     * Compute the cross product between this vector and another vector
     * @param other Arbitrary vector
     * @returns v1 x v2
     */
    cross(other: Vec3): Vec3;
    /**
     * Project this vector onto another vector
     * @param other Arbitrary vector
     * @returns proj_v2(v1)
     */
    projectOnto(other: Vec3): Vec3;
}