Matrix: Difference between revisions
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local positionBelow = vehicle.position - vehicle.matrix.up | local positionBelow = vehicle.position - vehicle.matrix.up | ||
</syntaxhighlight> | </syntaxhighlight> | ||
===Methods=== | ===Methods=== | ||
Revision as of 19:05, 22 November 2014
Matrices are one of the most powerful features of MTA OOP. We did have a presence of Matrices before with getElementMatrix, but we were given an ugly disgusting table to play with. Now, with the new Matrix class, we can make and magically manipulate Matrices.
Using Matrices
Say you wanted to create a bin - object 1337 - two units in front of a player. You don't want to manually do trigonometry and you don't want to play with the complicated tables. You just want to get the position two units in front of the player whilst taking into account the rotation of the player. You only need to use Matrix.getForward. Matrix.getPosition and getElementMatrix. It's just:
Object ( 1337, player.matrix.position + player.matrix.forward * 2 )
Why not stick to the good ol' tables?
Say you'd like to get find the position underneath a vehicle. This is the position at any rotation. So if it was upside down, the Z value would be higher than the vehicle Z value. If the vehicle was the right way round, the Z value for underneath car would be less than the Z value for the car.
--
-- Instead of:
--
local matrix = getElementMatrix(vehicle)
local offX = 0 * matrix[1][1] + 0 * matrix[2][1] - 1 * matrix[3][1] + matrix[4][1]
local offY = 0 * matrix[1][2] + 0 * matrix[2][2] - 1 * matrix[3][2] + matrix[4][2]
local offZ = 0 * matrix[1][3] + 0 * matrix[2][3] - 1 * matrix[3][3] + matrix[4][3]
local pX, pY, pZ = getElementPosition(vehicle)
local positionBelow = {offX-pX, offY-pY, offZ-pZ}
--
-- You only have to do:
--
local positionBelow = vehicle.position - vehicle.matrix.up