"Chris B" <nom### [at] nomailcom> wrote:
> "melo" <mel### [at] coxnet> wrote in message
> news:web.47a3eb67e148a5763c0d56f20@news.povray.org...
> >I am new to POV-RAY and animation, I have managed to create a H-ANIM
> >complaint
> > CSG based pov-ray Humanoid model and managed to provide AVARs (Animation
> > control
> > variables) to define control frame poses,  POV-RAY does animate each frame
> > wonderfully on its own.
> >
>
> Hi Melo,
>
> It's very brave to start with human animation as this is normally something
> of an advanced topic.
> I hope you mean you're new to animation with POV-Ray and not new to both
> animation and POV-Ray. Otherwise you may find the learning curve a bit
> steep.
> The wording you've used below is not totally clear to me, so forgive me if
> I've misunderstood anything;
>
> > I had placed each of my control frames in its own block using multi-stage
> > animation setup.
> >
> > What's missing is figuring out how to tie my frames smoothly.  Each pose
> > in each
> > frame involve quite a number of joint object (represented by spheres)
> > rotations
> > to take place.  The next frame needs to start off where the previous frame
> > left
> > off.  What I see instead my humanoid jumping all over the screen from
> > stage to
> > stage.
> >
>
> If I understand your code sample below correctly you already have a variable
> defined for the default position of each object - effectively an anatomical
> definition, based upon the default pose for H-Anim forms -  and a variable
> for each individual joint rotation (the pose). Presumably the unions in your
> CSG correspond to the anatomy so that successive rotations correctly adjust
> the ultimate position and orientation of any body parts that are affected by
> a succession of rotations by virtue of the fact that they are connected to
> other moving parts.
>
> If I understand your problem correctly you need some way of calculating
> intermediary sets of joint rotations so that you can engineer a smooth
> transition from one pose to another;
>
> > Is there a way to query coordinates of my AVAR joint objects from a nested
> > CSG
> > Object, which is what my Humanoid is, so I can transform my Humanoid to
> > where
> > the previous movements had left him at the beginning of the each new
> > stage?
> >
>
> I think what you're asking is to be able to do is to make a macro call from
> within the CSG definition that will look up two values for the same
> variable, from different pose files, and return an intermediary set of
> rotations. Conceptually it is possible and I can think of a number of
> approaches, but they all get pretty messy given the way your variables are
> defined. So you could have one macro per joint that reads one pose file,
> copies the required value into a temporary variable then reads the other
> pose file and returns the results of processing the two values, but this is
> extremely cumbersome and involves a lot of unnecessary IO. You could have a
> single macro and pass it some indication of which variable you want, but
> this is difficult and will also get very messy very quickly.
>
> The approach I took for POV-Person was to assign all of the rotations to an
> array, recording the array index into a variable with a real-world joint
> name, so I could access an individual rotation as
> JointRotations[L_Elbow_Ref], but it also meant that I could process the
> whole array by using a #while loop to loop through the array elements. To
> calculate intemediary poses I then used a macro to:
> 1. read one pose file
> 2. copy all elements into a temporary array
> 3. read a second pose file
> 4. copy all elements into a second temporary array
> 5. calculate the intermediary rotations (based on the desired interpolation
> methods -  linear, sinusoidal etc.) and write them back into the main array
> which the SDL could subsequently use to create the figure.
>
> This only had to process the two pose files once and could be run before
> building the CSG. From within the CSG you could then access the individual
> rotations using the 'JointRotations[L_Elbow_Ref]' notation.
>
> > After he walks he can learn TaiChi and Yoga with me.
> >
>
> There are already quite a few BVH files about, so he may be able to learn
> quicker than you. :-)
>
> > This is too much detail but the variable name declared for one joint
> > object
> > center is like
> >
> > #declare JOC_l_elbow = <a, b, c>; // These are from H-ANIM ISO standard
> > #declare JOC_l_wrist = <d, e, f>;
> >
> > #declare joint_radius_arm = 0.3; // These are some values I picked
> >
> > #declare l_elbow_ctl = <x, y, z>; // a rotation control vector  All my
> > AVARs
> >                            // have _ctl suffix, for an example I show one
> > here.
> >
> > then in my Humanoid CSG definition is something like
> >
> > #declare Humanoid =
> > Union {
> >  sphere{
> >  cone{..
> >  union{
> >    sphere{
> >    cone{
> >    sphere{
> >    cone{
> >    union{
> >      sphere{ JOC_l_elbow, joint_radius_arm }
> >      cone{ JOC_l_elbow, joint_radius_arm, JOC_l_wrist, 0.0 }
> >      #if ( VZero(r_elbow_ctl) )
> >      #else
> >         Rotate_Around_Trans( rl_elbow_ctl, JOC_l_elbow )
> >         //Rotate_Around_Trans( l_elbow_ctl, vtransform( JOC_l_elbow,
> > Human_Trans ) )
> >      #end
> >     }
> >      }
> >    }
> >  };
> >
>
> I hope I've understood your question correctly and that the answer helps in
> some way.
>
> Regards,
> Chris B.

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