Motion Builder - exporting an animation to an .mb
Note: Currently it's not advised to animate in MotionBuilder anymore, it's too complex and has too many points of failure. There are animation layers in Maya with a plugin, so there shouldn't be any need to animate in MotionBuilder.
Load the AnimRef_idle.fbx of the character you want, into Motion Builder, and animate with that. Currently we are using the "citywatch" for all base animations (that can be applied to other characters). This rig should already be facing along the X axis, but just ensure this is the case. Motion Builder defaults to the Z axis with a new model.
Before exporting, you have to do this ritual; up on the top right where the picture of the man is, there are some drop down menus... Click on "Edit", then "Plot Character", then click "Skeleton", then "Plot". DO NOT SAVE THE FILE. You definetly don't want to save after plotting to skeleton - you lose all your layer and keyframe data. Everything gets flattened to one layer with a key frame every frame for the entire body.
Click File, export, and from the file-type selector, choose "Kaydara FBX (Animation only)". Like it says, this will just be the animation only, and no cameras or models you may have in the scene. Now do "New" , "Don't Save" and then "Open" to re-open your file.
In Maya, open the fbx_import.mb. Then go File, Import, and choose your FBX file. If it says "Unrecognised File Type", just try it again... sometimes I try it 3 times in a row before it suddenly works. Also you may need to install the latest FBX importer plugin. Choose the Merge(Exclusive Merge) option on the importer dialogue.
The animation should play correctly in Maya at this point.
Now save as walk.mb or whatever animation name you want for Doom 3 to use. If you get some error about "No Disk In Drive" you'll find you won't be able to recover from this. You have to CTRL+ALT+DEL and end task Maya, click End Program in the dialogue, and then click Cancel on Maya's error dialogue till it closes. Start Maya again, and to avoid this error, click File, then click the box next to Save As, and then set all the radio buttons to "Never", and try saving again, it should work from now on.
After that you may have to close and re-open Maya to do another file, otherwise you get that crash.
From here on, use the Getting_Characters_and_their_Anims_into_Doom instructions to get it into Doom 3.