RE: Change quaternion FCurve interpolation?

["Brent McPherson" <brentmc(at)Softimage.COM>]

Agedito,

 

You should be able to go the scripted operator route as XSI has the math support built in.

 

A few years ago I did a similar operator as a proof-of-concept. The only problem is all I have is some (incomplete?) VB code I found on my disk but maybe it will give you some ideas. Unfortunately I don't remember too much else about how I set things up but I seem to remember I copied the original fcurves to parameters on the scripted operator and removed the original fcurves. I know at some point I switched from a scripted operator to a compiled operator but that may have been for performance and other reasons.

 

Anyway, here is the code I found. It might gives you some ideas on where to start if nothing else...

 

Cheers!

--

Brent

 

if In_UpdateContext.Mute.Value then
  out.value.rotx.value = input.value.rotx.value
  out.value.roty.value = input.value.roty.value
  out.value.rotz.value = input.value.rotz.value
else
  ' Get rotation fcurve info
  dim kine, rotx, roty, rotz, fcx, fcy, fcz
  ' set kine = input.value
  ' set rotx = kine.parameters("rotx")
  ' set roty = kine.parameters("roty")
  ' set rotz = kine.parameters("rotz")
  set rotx = In_UpdateContext.rotx
  set roty = In_UpdateContext.roty
  set rotz = In_UpdateContext.rotz
  set fcx  = getsource(rotx.fullname)(0)
  set fcy  = getsource(roty.fullname)(0)
  set fcz  = getsource(rotz.fullname)(0)

 

  ' Get number of keyframes
  dim xkeys, ykeys, zkeys
  GetFCurveInfo fcx,,, xkeys
  GetFCurveInfo fcy,,, ykeys
  GetFCurveInfo fcz,,, zkeys

 

  ' Make sure fcurves have the same number of keyframes
  if xkeys < 2 or xkeys <> ykeys or xkeys <> zkeys then
    out.value.rotx.value = input.value.rotx.value
    out.value.roty.value = input.value.roty.value
    out.value.rotz.value = input.value.rotz.value
    LogMessage "not enough keyframes"
  else
    dim current

 

    ' TODO: handle different frame rates
    current = In_UpdateContext.currentframe / 29.97

 

    dim i, t, t1, t2, x1, y1, z1, x2, y2, z2

 

    for i = 0 to xkeys - 1
      GetKeyInfo fcx, i, t2, x2

 

      if current < t2 then
        if i = 0 then
          out.value.rotx.value = rotx.value
          out.value.roty.value = roty.value
          out.value.rotz.value = rotz.value
        else
          ' TODO: handle rotorder
          GetKeyInfo fcy, i,  , y2
          GetKeyInfo fcz, i,  , z2
          GetKeyInfo fcy, i-1,, y1
          GetKeyInfo fcz, i-1,, z1

 

          x1 = XSIMath.DegreesToRadians(x1)
          y1 = XSIMath.DegreesToRadians(y1)
          z1 = XSIMath.DegreesToRadians(z1)
          x2 = XSIMath.DegreesToRadians(x2)
          y2 = XSIMath.DegreesToRadians(y2)
          z2 = XSIMath.DegreesToRadians(z2)

 

          ' Interpolate
          r1.SetFromXYZAnglesValues x1, y1, z1
          r1.GetQuaternion q1
          r1.SetFromXYZAnglesValues x2, y2, z2
          r1.GetQuaternion q2
          t = (current - t1) / (t2 - t1)
          q3.SLerp q1, q2, t
          Out.value.quatw.value = q3.w
          Out.value.quatx.value = q3.x
          Out.value.quaty.value = q3.y
          Out.value.quatz.value = q3.z
        end if
        i = xkeys - 1
      elseif i = xkeys - 1 then
        out.value.rotx.value = rotx.value
        out.value.roty.value = roty.value
        out.value.rotz.value = rotz.value
      else
        t1 = t2
        x1 = x2
     end if
    next
  end if
end if

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From: owner-xsi(at)Softimage.COM [mailto:owner-xsi(at)Softimage.COM] On Behalf Of Agedito
Sent: Thursday, September 28, 2006 11:14 PM
To: XSI(at)Softimage.COM
Subject: RE: Change quaternion FCurve interpolation?

Thanks Brent.

 

It’ bad new that it’s impossible to access it L  I need to change it to lineal. L

 

Thanks again

 

---

De: owner-xsi(at)Softimage.COM [mailto:owner-xsi(at)Softimage.COM] En nombre de Brent McPherson
Enviado el: viernes, 29 de septiembre de 2006 0:02
Para: XSI(at)Softimage.COM
Asunto: RE: Change quaternion FCurve interpolation?

 

Sorry, I do not believe it is possible to do this in scripting.

 

The quaternion fcurve is a completely different type of curve in XSI and it has not been exposed through scripting. Also, you need to be careful when using quaternion fcurves since they cannot be exported to different file formats.

 

If you want something like simple spherical linear interpolation might be better to roll you own using a custom operator attached to the rotation parameters. (e.g. grab the fcurves, read the key values, and then do your own slerp)

--

Brent

 

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From: owner-xsi(at)Softimage.COM [mailto:owner-xsi(at)Softimage.COM] On Behalf Of Agedito
Sent: Thursday, September 28, 2006 10:29 PM
To: XSI(at)Softimage.COM
Subject: RV: Change quaternion FCurve interpolation?

Thanks Brent, but I need do  it by scripting.

Any idea?

 

 

 

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De: owner-xsi(at)Softimage.COM [mailto:owner-xsi(at)Softimage.COM] En nombre de Brent McPherson
Enviado el: jueves, 28 de septiembre de 2006 23:23
Para: XSI(at)Softimage.COM
Asunto: RE: Change quaternion FCurve interpolation?

 

Agedito,

 

Open the animation editor, select all three curves (but don't select any keys on the curves) and hit the linear interpolation button in the toolbar.

 

Cheers!

--

Brent

 

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From: owner-xsi(at)Softimage.COM [mailto:owner-xsi(at)Softimage.COM] On Behalf Of Agedito
Sent: Thursday, September 28, 2006 9:30 PM
To: XSI(at)Softimage.COM
Subject: Change quaternion FCurve interpolation?

Hello


I have a rotation animation and I convert it to quaternions with the command: ConvertEulerToQuat();

 

Ok, the quaternions FCurve are spline interpolated and I need to change the interpolation to lineal. I dont found how do it, I'd tryed all the methods but If the FCurve is euler runs but if it's quaternion don't run.

Is posibble to do it by hand in the Animation Editor.  Is there any scripting way?

Thanks in advanced