[Question] How to properly use math.cos and math.sin to set positions

[kieran]

I'll be straight up, took the following code straight off another topic from a while back where the guy was getting a ramp to spawn in front of the player, I modified it to move the player, but it moves them forwards and I want to move them backwards....  I am not the best at math but I am trying to learn from scripting, code to move player forwards is below.

local x, y, z = getElementPosition ( localPlayer ) 
local r = getPedRotation ( localPlayer ) 
x = x + math.sin ( math.rad ( r ) ) * 1.5 --What does this actually do?
y = y - math.cos ( math.rad ( r ) ) * 1.5 --And this? 
setElementPosition ( localPlayer, x, y, z ) 
setElementRotation ( localPlayer, 0, 0, r ) 

Can someone explain what's actually happening?  It works but my problem is dealing with: math.sin, math.cos and math.rad.  Any info would be greatly appreciated.

[NeXuS™]

I'd rather start using OOP, as math.sin and math.cos are taught in school.

[kieran]

12 minutes ago, NeXuS™ said:

I'd rather start using OOP, as math.sin and math.cos are taught in school.

I've never touched OOP...  What would I need to know for this?  Only reason I ask is that I have made a script for a friend where the player climbs up a ladder, that part works fine, but when they go down the ladder (even if I spin  them 180 degrees) they glitch through walls and it's horrible.

[NeXuS™]

Read this page.

[kieran]

3 hours ago, NeXuS™ said:

Read this page.

Ah thanks, I should of payed attention instead of drawing triangles in class.

[IIYAMA]

 

The value 1.5 represents the offset.

 

Math.sin and math.rad used on the rotation, represents a sort of vector direction of an axis. Which you can multiply by the offset to extend the range. (The original offset is 1 unit.)

 

You should start calculating from the ladder and not from the ped. Else indeed it might causes glitches like that.

Edited February 4, 2018 by IIYAMA