Currently if you prefer working Y-up in Maya you will have to create a SceneRoot node which encapsulates your skeleton, then rotated to be standing up in Y-axis (this means your default orientation should be set with Z-up.) What this means is that it allows you to export your assets technically as Z up. The reason for this is that the exporter does not convert joint orientations from y to z so you can use this node to get the best of both orientations. Correct joint orientations are necessary in order to get proper ragdoll simulation in Sandbox.

• Any rotations etc that are on the SceneRoot node will be ignored. I.e. The 90 you have there will not go through to the game. If you set the rotations on the SceneRoot node to 0. The scene will look the same as the game.
• The SceneRoot node is used to transform the space under it to be the same as the game, z-up. You then export with `export as z-up` checked to make sure RC doesn't try to fix the rotations that you have already handled using the SceneRoot node.

Here is an example of how SceneRoot effects joints:

This is a character setup in Maya

This is the same character in Sandbox

In Sandbox but exported with Z up checked and SceneRoot group node