L155 CrossProduct Clarification

[John78]

I know this is quite a dumb question. But why isit that the Z axis is the value to pass in for the IntentTurnRight() function. From my understanding the cross product is a vector that is perpendicular to the 2 vector TankForward and AIForwardIntention. Why isit that using the Z value of the new vector will result the tank to rotate towards the player direction.

[ben]

We are just thinking of the time turns in terms of a rotation around the Z axis, does that help?

[John78]

Thanks for the reply.

Ah, so we are just thinking the amount of rotation around the Z axis. In another words the value of Z is the new position of a perpendicular vector.
But also the value is the amount we need to turn the tank to have the “TankForward” align with “AIForwardIntention” value.

After trying out on a cross product calculator. I think i see the relationship.

e.g

X means Cross Product Function

(1,1,1) X (1,1,1) = (0,0,0)
(1,2,1) X (1,1,1) = (1,0,-1) <— the Z is -1 hence we need to turn -1 on the Z axis. So that both the forward and turn right vector can align.

( 1,3,1) X (1,1,1) = ( 2,0,-2) <-- the Z is -2 hence we need to turn -2 on the Z axis. So that both the forward and turn right vector can align.

Please let me know if I am still not understanding it correctly.

[Nacapa_Alberto]

I wrote a post about a similar concept, I don’t know if it helps:

Why using CrossProduct.Magnitude instead of Z doesn't work at all

I don’t know if this will help anyone, or if everyone already knows this, but here it is. I was wondering why we are using CrossProduct.Z instead of the magnitude of the CrossProduct : CrossProduct(a, b).Size() I actually used the magnitude in the challenge, and according to the cross product diagram it should have the same results (except from the fact that the tank would always turn right, because magnitude would always be positive): [image] To my surprise, while using Z worked fine, usin…