PiConverter is used to convert assets or shots from Maya to Unreal formats.
In the “Asset Converter” pane, the two buttons are for different conversion options:
Use Full Precision UVs: Turned this on to use 32 bit UVs, or left to save memory, thereby using 16 bit UVs.
Update Mesh: Convert and update only the meshes of the asset. It is useful when you modified the materials of the asset in Unreal Editor, and later you want to reimport the mesh but keep the materials intact.
Convert: Convert the currently opened asset to the Unreal asset format (.uasset).
In the “Shot Converter” pane, there are 3 inputs:
Sample By: The frequency with which PiConverter will generate a keyframe. Greater values decrease the frequency of generated keys, and smaller values increase the frequency. For example, a value of 1 creates a key per frame, 0.5 creates 2 keys per frame and 2 creates 1 key every 2 frames. Using larger values may introduce slight differences in animation curves between Maya and Unreal.
Start Frame, End Frame: Set the export range here. The default values are the same as Maya’s playback range settings.
The following buttons are for converting and partially updating shots
Update Selection: Add or update the selected actors in Maya to the existing Unreal level (.umap). This is for adding new characters or updating animations of existing actors to the map but keeping the other parts intact.
Update All: Update all actors in a Maya shot. This is used in case you have added additional objects (e.g. particle emitters) to the map in Unreal Editor, “Update All” will convert all Maya only actors without touching the Unreal actors. The difference between “Update”/”Update All” and “Convert” is that “Convert” will create a new .umap file while “Update” will only update an existing one.
Convert: Convert everything from Maya and replace the previous map.