Previously, exports of block rigs made using the Rig Builder plugin could be exported such that all of the limbs remain separate poseable parts. However, an update made after April 25th has broken this feature and caused studio to export the entire rig as a single part.
This is an OBJ for an overseer rig exported from studio on 4/25/2020 in Cinema 4D
As you can see, all of the limbs are displayed as separate parts on the top right object viewer
Now here is the same rig from the same studio file exported today
The rig is no longer being separated at all and limbs cannot be moved without editing the mesh faces.
Steps for replication
-Create an R15 Block Rig using the Rig Builder plugin
-Export the rig as an OBJ by right clicking it from the explorer
-Import into Cinema 4D
Import settings seem to have no effect on this issue, though I have uploaded a picture of the specific settings I used for both models below.
Exported OBJs can be downloaded here
test.obj (782.9 KB)
Overseer Magic.obj (783.4 KB)
Overseer.rbxm (12.7 KB)