I made this test by creating 2 objects (cube and cylinder) in Modo, setting up a 121 frame camera path animation at 24fps and 720p, rendering this in Modo to create a backplate, and then exporting the scene to fbx. I imported the fbx into Embergen, and made sure that the 24fps frame rate was set in the simulation, imported camera and output etc. I mapped the cube and cylinder to colliders, and brought in the animated backplate in the camera. I rendered this out of Embergen, and then layered this plus the original backplate in AE. I set the original backplate layer to a red transparent color. In spite of carefully setting everything to start at frame 0 and to run for 121 frames, I ended up with a 1-frame offset in the Embergen output render (I had an end frame as frame 0). I slid this layer over by 1 frame, and this lined things up - more or less. As you can see, we see the same periodic slippage between the Embergen backplate objects (in grey) and the overlaid Original backplate (in transparent red) - these have been mentioned in a previous post. The imported objects (in purple) are obviously off by quite a bit. To me it looks like mismatched camera settings (especially focal length) are the problem here - would be great if those type of settings were more advanced, and allowed you to override them after import - or would more accurately reflect the camera parameters from the fbx file. Love Embergen in general so far, but this kind of issue limits how useful it can be for VFX compositing.