[Papervision3D] BUG GreatWhite (and previous versions) - Rotation issue solution. DisplayObject3D

[Chris Maloney]

Hello everyone,

 

I've been beating my head against the wall the last few days trying to
figure out why my rotations were changing when they should never be
changing.  So, over the last few hours this morning I tracked down the
bug in the GreatWhite source code. Also, with browsing the repository I
see this same issue in previous versions and I've also proven it with
the 1.5 code download from the google code site.  

 

In DisplayObject3D the function updateTransform() is called when the
transformation is flagged as dirty.

 

The line:

transform.copy(m);

 

Should actually be:

transform.calculateMultiply3x3(this.transform, m);

 

Because, any changes I make to the transformation matrix prior to
updateTransform() is called is overwritten by using the
transform.copy(m); and results in some serious hair pulling.

 

If you need to see code that proves this, see my previous post entitled
"GreatWhite rotation issues"

 

Best regards,

Chris Maloney

 

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