Animate Bones and Markers : Importing mesh models into Maya from Horos
    In Maya, select imp on the MayaTool Shelf
    Click on impObjs, select the file and click OK
    Repeat for each model
    Hover mouse over models and press number key 5 for "smooth shade."
    Press number key 4 to toggle back to mesh view, and then 5 again
    Placing each model into a separate layer makes it easy to turn visibility off and on.
      Select the object you wish to create a layer for.
      On the right side of the screen, click on the Channel Box/Layer Editor tab.
      Click Layers -> Create Layer from Selected
      Double click on the "Layer1" and rename the layer to the name of the bone.
      Clicking on the left box (highlighted in green) will make the object visible or invisible.
      Clicking on the right box will (highlighted in yellow)
        T- Make the object transparent
        R- Make the object fully visible but unable to be selected

Correcting models from Horos

Models created in Horos have two issues when imported into Maya:

    they are in units of mm, so they 10x too large for the cm scale in Maya (see how small and far away the reference grid is in the image below?)
    they have irregular polygon normals, so the surface reflects light incorrectly in Maya smooth shade mode
To scale models down to 0.1x size:
    Shift-select all imported models in the scene (bone and marker models)
    Press button in farthest right top corner of the Maya window to open Channel Box/Layer Editor (if it is not already open)
    Set all of the 1s to the right of Scale X, Y, Z, to the value 0.1 (see image above). The grid is now large relative to the model (image below).
    Shift-select the three Scale attribute names (the words Scale X, Scale Y, Scale Z), then right click and Select Freeze/Scale (image below). This will set the scale back to 1 without changing the size of the models. This effectively sets the scale for your models to cm, which are the units we use for XROMM.

To correct the normals:

    Select the Polygons menu set from the far left top of Maya window
    Select one of your bones (best to do them one at a time)
    Select Normals/Set to Face from the top menu bar (image below)
    Wait. Setting normals to face can take a while, depending on how dense the polygons are on your model. It is a good idea to reduce the number of polygons coming out of Horos with the decimate function. When finished, your model will look smooth (image below)