Print Page - How to set a matrix x angle to zero ?

Title: How to set a matrix x angle to zero ?
Post by: gamenewer on October 20, 2014, 11:19:10 AM

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

Title: Re: How to set a matrix x angle to zero ?
Post by: EgonOlsen on October 20, 2014, 11:23:55 AM

I don't get the question... ???

Title: Re: How to set a matrix x angle to zero ?
Post by: gamenewer on October 20, 2014, 11:41:19 AM

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

Title: Re: How to set a matrix x angle to zero ?
Post by: EgonOlsen on October 20, 2014, 12:25:51 PM

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

Title: Re: How to set a matrix x angle to zero ?
Post by: gamenewer on October 20, 2014, 01:57:06 PM

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);

Title: Re: How to set a matrix x angle to zero ?
Post by: EgonOlsen on October 20, 2014, 02:06:43 PM

posAhead.x=0!?

Title: Re: How to set a matrix x angle to zero ?
Post by: gamenewer on October 20, 2014, 02:09:13 PM

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

Title: Re: How to set a matrix x angle to zero ?
Post by: EgonOlsen on October 20, 2014, 02:25:02 PM

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

Title: Re: How to set a matrix x angle to zero ?
Post by: gamenewer on October 20, 2014, 02:33:20 PM

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

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jPCT-AE - a 3d engine for Android => Support => Topic started by: gamenewer on October 20, 2014, 11:19:10 AM