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The Left-Hand Rule



Leadwerks uses a left-handed coordinate system. This means that if you hold your left hand as shown below, your middle finger, index finger, and thumb will point in the directions of the X, Y, and Z axes, respectively.




Rotations use the left-handed rotation rule. To predict the direction of positive rotation, curl your fingers on your left hand and point your thumb in the direction of the rotational axis. Your fingers will curl in the direction of positive rotation along that axis.




This will help you remember how your rotation values affect objects in 3D space.


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Question, why did you/your team decide to use Y as up while other applications and engines use Z? Is it because Y is easier to remember as up because of all 2D Graphs? Just curious.

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+Y = up is more commonly used in games. I find it a lot more intuitive as well, since z often means depth.


I kept the left-hand rule for rotation simply because it was easier to remember to use the same hand.


This is all in the documentation, but I was just using this and thought it was worth noting, and it would be interesting to see if everyone knew this already.

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That solves nothing and only introduces problems when people try to apply math concepts that are "handedness" dependent in Leadwerks as right handed systems are the default in all of math and physics unless explicitly stated otherwise.. Is there any good reason why you did it? +Y can be easily achieved in right handed systems as well, as you just rotate the system as a whole.


EDIT: Here Unity is left-handed too, I don't get why engine devs do this silly thing on purpose.

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If there is a standard for games, it is the left-hand coordinate system, since this is what DirectX uses. I find it much more intuitive that up, right, and forward would all be positive directions.

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about Y

if u look at the monitor it shows a plane with x,y , same a paper have.

the depth with z came later.

i think this left-handed system is perfect.

but it make sense to name the axis as people want via config.

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