How to set a matrix x angle to zero ?

[gamenewer]

Maybe this question is very simple,  but i  don't know how to do so , forgive me

[EgonOlsen]

I don't get the question...

[gamenewer]

I get a matrix  from a vector , I only want to rotate my car by  Y and Z , so I must  set the X angle to 0 , but  I don't know how to set  x angle to 0

[EgonOlsen]

By setting the x-component of the vector to 0 in the first place?

[gamenewer]

Wow,  I perform an  lookat action, 　I get the SimpleVector from a curve , and   get this SimpleVector matrix , then set the car by this matrix ,

                        SimpleVector posAhead = way.PointOnPath(xp);   
         SimpleVector poscur = getTransformedCenter();
         posAhead.sub(poscur);
         rotMatrix=posAhead.getRotationMatrix();

                        //here    must set  X angle to 0
                        ? setXangle = 0
                        //
                        setRotationMatrix(rotMatrix);

[EgonOlsen]

posAhead.x=0!?

[gamenewer]

if  I  set  posAhead.x=0  , the car will rotate  very strange  and not perform a lookat action,  So it's not right

[EgonOlsen]

My bad...i actually meant to 0 y, not x.

[gamenewer]

You are greate !    set Y  = 0  it's OK !