New to 3D stuff have a question about object origins

[Cratermaker]

This isn't necessarily a flight sim question. I'm trying to make a 3D object, whose destination is a DirectX object (.x file). My question is, either specific to this or any 3D object designing, how do I specify the origin of the object? This is the center of the object that it will rotate around.

I am using Google sketchup and a plug-in to export to DirectX objects.

 

[Milton Shupe]

In teh 3D design world, there should always be a center of the universe usually represented by a grid and a intersection at x,y,z coordinates of 0,0,0.

Also each object created has a gizmo or pivot represented by x,y,z coordinates. This can usually be adjusted for each object to align with the object, with the world, etc. Once you center the object's pivot to the object, then you can center the object to the scene or universe 0,0,0 coordnates.

 

[Cratermaker]

Sometimes it is the simple things you overlook. By sliding the whole model to center over the world origin before exporting, it made the center of the object where it needed to be. My routines rotate it around that point now.

 

[Milton Shupe]

Sometimes it is the simple things you overlook. By sliding the whole model to center over the world origin before exporting, it made the center of the object where it needed to be. My routines rotate it around that point now.

Keep in mind that by default, the origin is the FS Reference point unless you alter it in the aircraft.cfg.
You might set the crosshairs of the origin so that they match up with aircraft centerline, the thrustline, and the wing at 25% MAC. This basically sets the aircraft at approximate center of gravity and simplifies the aircraft.cfg setup.