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XYZ coordinates Blender to Oolite

Posted: Sat Dec 08, 2012 1:57 pm
by d8sconz
I can't get the orientation correct when I export from blender to the .obj file, and from there into Oolite. There are options for stipulating which axis is up and which is forward when you export to .obj from Blender. It seems that no matter what I try, the orientation is wrong by the time I get it into the game. Also, the result seems to have nothing in common with my choices in the export options (if I choose 'Z' up, it is facing forward in the game etc.). Can someone advise, what are the correct 'Up' and 'Forward' options in Blender when exporting. Many thanks.

Re: XYZ coordinates Blender to Oolite

Posted: Sat Dec 08, 2012 2:05 pm
by Wildeblood
Y is up, Z is forward.

Re: XYZ coordinates Blender to Oolite

Posted: Mon Dec 10, 2012 5:15 am
by d8sconz
Thanks Wildeblood, but I managed to finally get it done through trial and error. Interestingly, the coordinate choices for export that worked were the opposite of your suggestion (I used 'Y' forward and 'Z' up). That may have something to do with me reorienting the model in Blender as well. Also, for others who may be grappling with this issue, I spent a lot of time aligning the exhaust plume to the model. The wiki says the x,y,z coordinates for that effect are measured from the origin of the model. In fact the coordinates are from the world origin in Blender, which is a whole different kettle of fish. Once I've sorted out these things I'll try to put together a quick tutorial for other Blender users out there.

Re: XYZ coordinates Blender to Oolite

Posted: Mon Dec 10, 2012 7:57 am
by Zieman
Funny thing about the Y - Z switching, in Oolite Z positive is forward (for example, if you increase a subentity's z-coordinate, it will be positioned more forward relative to main entity).

Model origin vs world origin: any models you make for Oolite this should be the same. Having any single object centered already in 3D program makes life a lot easier when fixing the .plist to make said object to appear in Oolite.

Re: XYZ coordinates Blender to Oolite

Posted: Mon Dec 10, 2012 11:36 am
by Commander McLane
d8sconz wrote:
The wiki says the x,y,z coordinates for that effect are measured from the origin of the model. In fact the coordinates are from the world origin in Blender, which is a whole different kettle of fish.
I think that's exactly the same fish. The origin of the coordinate system in your 3D-modeling program automatically becomes the origin of this model in Oolite. That's kinda the point of it all, isn't it?

So, if you for some reason decide to create your model in front of the blue/red/green coordinate arrows in Blender (instead of around them), the origin of your model in Oolite will be behind it.

That's also why it's a good idea to centre your model in your 3D-modeling program.

Re: XYZ coordinates Blender to Oolite

Posted: Mon Dec 10, 2012 12:45 pm
by Smivs
d8sconz wrote:
...I'll try to put together a quick tutorial for other Blender users out there.
There is already a Blender Tutorial here on the BB :)