model coordinates

Hello,

I created a model with an armature in blender with positive Z up, positive X right, and positive Y into the screen. I then used the chicken egg exporter to obtain an egg file.

I then load the model in to my application where the world coordinates are the same orientation as blender. Everything is all well and good, model is displayed properly, and displayed where I expect it to be.

I then call controlJoint on the models ankle and shin, and then call getPos on the nodePaths returned from controlJoint. For the ankle I get a position of (0,7,0) which the way I understand it is relative to its parent, the shin, which is the correct , but it concerns me that the positive y axis is now pointing downward.

Playing around for a bit I discover that the local model coordinates have positive Z pointing out of the screen, positive X pointing left, and positive Y pointing down.

Does anyone have an idea of what caused the coordinate system to be modified? Any tips on where to look?

I am a experienced programmer, but not so experienced with 3d modeling.

Thanks,
C. David

This is normal.
If you look in Blender at the axis when in Armature Edit mode, you will see the axis different too.

Thats the way ALL blender object local axis are. That confounded me for almost two years when I first started using blender. I seems silly to me now but its just one of those things I have gotten use to. That is why I use show axis on every blender object so I am not confused.