Re: [TuxKart-devel] Getting Started.

[Steve B. <sjb...@ai...>]

Ingo Ruhnke wrote:

> I don't have experience with ODE and it seems pretty nice for boxes
> that bounce around and such. However for Tuxkart I think all we need
> is basically a 2D physics model, I don't want to see Karts crashing
> realistically and go upside down and such, I want the Kart to stay
> flat on the ground and allow nice drifts in the curves and I am not
> sure how difficult it would be to get this drifting right with ODE.

2D definitely won't work - we need ramps and jumps and banked tracks,
you can't do that in 2D.   If you want to simulate drift, you *need*
banked tracks on some of the courses.

I'm suprised you don't like the idea of being able to go upside-down.
There are some really neat effects like that in some other Kart games.

> Beside the lack of drift and some lack of precision in the collision
> detection (easy to push other players through a wall) the current
> physics seem already be quite useable.

They are *very* crude...we aren't talking a small change here.

If it's not ODE, it's still a pretty big change.

>>It's not clear whether we have to improve TuxKart's handling of '.ac', improve
>>Blender's exporter, or write an entire new '.blend' loader for AC3D.  Comments
>>please?
> 
> 
> A .blend loader is unrealistic I think, unless things changed
> recently.blend file format is still more or less a memory dump of
> internal Blender structures and not meant to be read by other apps.

Ack.  I didn't know that.  So it probably changes over time too.

OK - so no blender loader  :-(

> There his however a .xml based fileformat planed, but that isn't
> present in the current version.

Could we contribute to that - or try to push the blender community
to get their act together?

 > A custom exporter is needed and
> shouldn't be too difficult to create in the long run, for the time
> being the standard .ac exporter seems to be enough.

That's certainly my hope - but it's not my expectation.  :-(

There are an awful lot of things AC3D can't represent.  No vertex
colours (which are useful for track design), no animation whatever
(useful for...well...everything really), no LOD control.

I've kinda kludged around those things where I can - but it's not
a pretty sight!

* I use the texture filename as a key to a 'material properties table'
   that allows me to add per-texture data like friction and 'zipperness'.

* I recognise comment fields in the AC3D file for some kinds of effects
   such as objects that spin or slide in a repetitive manner, moving
   texture (nice for water, lava, electrical sparks and arcs, etc).

   Dunno if comments can be entered in Blender - and I don't know whether
   they survive being written to AC3D format intact.

* Some effects (such as the spinning herring) are hard-coded into the game.

---------------------------- Steve Baker -------------------------
HomeEmail: <sjb...@ai...>    WorkEmail: <sj...@li...>
HomePage : http://www.sjbaker.org
Projects : http://plib.sf.net    http://tuxaqfh.sf.net
            http://tuxkart.sf.net http://prettypoly.sf.net
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