New exporter option: Export only key frames

[oldmanauz]

1. Added an export option to only export key frames of an animation.
2. Updated documentation

[paroj]

Also I just noticed issue #87. I haven't looked yet, but if this code is easily portable, do you want an option for node animation to export only key frames or be the ONLY option when exporting key frames?

an option just like the one you introduced here.

[sercero]

@oldmanauz be careful because the idea of exporting every frame is to have Blender do the interpolation instead of OGRE. That is because there are some complex interpolations that OGRE cannot do.

And even the interpolations that OGRE can do, there is a loss of information because it is possible to tune the interpolation curves in Blender and OGRE would be none the wiser, please take that into account in your modifications.

Thanks!

[oldmanauz]

@sercero I realise it does has limitations but It does solve a purpose. I documented that accordingly.

From what I see, I pretty much did exactly the same as what you started to implement in export_node. Did you try to get any futher with your version or did you just stop at exporting key frames every frame?

[sercero]

@sercero I realise it does has limitations but It does solve a purpose. I documented that accordingly.

From what I see, I pretty much did exactly the same as what you started to implement in export_node. Did you try to get any futher with your version or did you just stop at exporting key frames every frame?

I just stopped at exporting key frames every frame because my approach did not seem good enough, perhaps you came out with something better.