[Plib-devel] Implement ssgAnimTransform?

[Wolfram K. <w_...@rz...>]

As you know, I am working on PPE.
I now need the option to display animations of models to be converted
in PPE. The viewer sample loads animation from *.ase files and
displays it. I have have tweaked the ASE loader to handle a new kind
of animation I need and also I have moved the code "doing" the
animation into PLIB and called it from PPE. It "works" so far, see
below. I have not committed it yet. I am absolutely prepared to share
all code I have, but right now it is not fit to be comitted and it
might just be that I have to kludge things in this insane hurry enough
so that it is of no general interest. This is however just what I want
to avoid.

The animation data consists of different transform matrices for
different times/frames.

=46unctionalitywise, the bad thing about the current implementation is
that the viewer code puts the animation data into the user data field.
Since PPE uses this field when selecting, the animation works till the
first time you select something. Also, the code is very different to
the animation code we did later, for example, it does not use the
animation modes etc. Does it make sense to implement and commit the
following?:

There would be a ssgAnimTransform which is derived from ssgTransform.
It contains a array of "frame" matrices. There will be a global ssg
function "ssgSetAnimTime" with the "time" as parameter that walks the
tree and for each ssgAnimTransform it sets the main transform from
either one of the "frame" matrices (discreet animation) or a
interpolation between two (smooth animation). The app could call this
function before ssgCullAndDraw().

It would be similar to the existing animation, for example with a
float time like in ssgTween instead of a discreet one as in the viewer
example.

Also, there is the exposer demo showing off bones, but I doubt much
code can be shared.

All current apps would not be affected. Only if they load an ase file
with animation will the ssgAnimTransform be created and these would
only be active iff the app calls the ssgSetAnimTime function.

Also, I could implement a global variable saying "Something animated
has been loaded" so that the ssgSetAnimTime function is only called if
needed.=20

This feature would be used in the viewer sample, in PPE and I can well
imagine games authors using it as simple way to get animated objects
into their game.

Bye bye,
Wolfram.