User Guide

296 Chapter 12: Methods

dotProduct()

Usage

vector1.dotProduct(vector2)

Description

3D vector method; returns the sum of the products of the x, y, and z components of two vectors.

If both vectors are normalized, the

dotproduct is the cosine of the angle between the two vectors.

To manually arrive at the dot of two vectors, multiply the x component of

vector1 by the x

component of

vector2, then multiply the y component of vector1 by the y component of

vector2, then multiply the z component of vector1 by the z component of vector2, and finally

add the three products together.

This method is identical to

dot() function.

Parameters

vector2

Required. The second vector from which a sum is returned.

Example

In this example, the angle between the vectors pos5 and pos6 is 45°. The getNormalized

function returns the normalized values of

pos5 and pos6, and stores them in the variables norm1

and

norm2. The dotProduct of norm1 and norm2 is 0.7071, which is the cosine of 45°.

pos5 = vector(100, 100, 0)

pos6 = vector(0, 100, 0)

put pos5.angleBetween(pos6)

-- 45.0000

norm1 = pos5.getNormalized()

put norm1

-- vector( 0.7071, 0.7071, 0.0000 )

norm2 = pos6.getNormalized()

put norm2

-- vector( 0.0000, 1.0000, 0.0000 )

put norm1.dotProduct(norm2)

-- 0.7071