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There are a number of ways to manipulate and combine vectors with simple operations (vector maths).
Addition and Subtraction
If you add to vectors together, the resulting vector is the equivalent of stacking the vectors end to end. Adding vectors together can be used to simulate simple physics like the effect of wind or gravity, so for every step forward a game character might have a wind vector added to their movement vector. If a character in a game jumps while moving forward, then we also want to add the vectors of the upward movement with the forward motion, and then in reverse when they fall back down.
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Diagram 4. Vector addition
Subtraction
Subtracting two vectors
Scaler Multiplication
Scaler Multiplication only effects the magnitude of the vector, leaving the direction unchanged... However, if the vector is multiplied by a negative, then the direction is reversed! Multiplying vectors could Scaler Multiplication can be used to control the acceleration of space ship , ot to simulate wind resistance or drag. If an object in a game collides with wall for example, we may want to multiply the objects vector by -1, to reverse it's direction so that it bounces off the surface.
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