Re: [JAVA3D] non-uniform scale interpolation - esp. to the author of the KBRotPosScaleSplinePathInterpolator CLASS

[J. Lee Dixon]

I hit this exact same piece of code several months back and sent a
message as well.  I thought they had fixed it by now.  Here's what I
did:

I had to make my own package using their code, but changed that area of
code to:

            // TODO: Vijay - Handle Non-Uniform scale
            // Currently this interpolator does not handle non uniform
scale
            // We cheat by just taking the x scale component
//          sMat.set((double)iScale.x);
            tMat.set(iQuat);
//          tMat.mul(sMat);

            // Set the translation components.
            tMat.m03 = iPos.x;
            tMat.m13 = iPos.y;
            tMat.m23 = iPos.z;
            rotation.set(tMat);

            // construct a Transform3D from:  axis * rotation *
axisInverse
            temp.mul(axis, rotation);
     temp.setScale(new Vector3d(iScale));
            temp.mul(temp, axisInverse);
            target.setTransform(temp);

Seemed to work for me.  I just looked in my code though, and with their
latest release I stopped using my "fixed" version of their code because
I thought they had fixed their version.... can't remember now.  I'll
have to check.

-Lee

-----Original Message-----
From: Liming CHEN [mailto:[EMAIL PROTECTED]]
Sent: Monday, January 15, 2001 12:03 PM
To: [EMAIL PROTECTED]
Subject: [JAVA3D] non-uniform scale interpolation - esp. to the author
of the KBRotPosScaleSplinePathInterpolator CLASS


 Dear all,

The core class RotPosScalePathInterpolator does not support non-uniform
interpolation. The RotPosScaleTCBSplinePathInterpolator or
KBRotPosScaleSplinePathInterpolator  classes in the Utility pack do not
support
such function too. I have checked the souce code of the above classes.
Here is what
they said:

            // TODO: Vijay - Handle Non-Uniform scale
            // Currently this interpolator does not handle non uniform
scale
            // We cheat by just taking the x scale component

           // Scale the transformation matrix
     sMat.set((double)iScale.x);
     tMat.mul(sMat);

     // Set the translation components.
     tMat.m03 = iPos.x;
     tMat.m13 = iPos.y;
     tMat.m23 = iPos.z;
     rotation.set(tMat);

My question is if I replace the  sMat.set((double)iScale.x) with
rotation.setScale(iScale), (that means that the Transform3D contains a
non-form
information), then the class will support the non-uniform scale
onterpolation. I
doubt if it is so simple.

Could someone or the author of these Util classes give me a clue? Are
there other
options?

Thanks

liming

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