Before I decided to post, I went on an intensive search for any solution to this problem both internally and on the forums + google with only one post that mentioned this issue but no solution. Frankly, I'm very surprised that this issue hasn't been resolved as it's very important in VFX industry that exported nulls work properly to the rendered plate.
The issue is that when I apply an External compositing tag to scene objects, I am expecting them to line-up pixel-perfect in After Effects but with Octane this doesn't seem to be possible. The nulls slide and it is not a practical solution. I work in NY with several large studios such as the Mill, MPC, etc. and having discovered this problem, I don't think I can recommend Octane for further projects until this issue gets resolved.
As you can see, I imported the rendered backplate (rendered in Octane) back into C4D, the white box constantly slides in position and then out of position (In Frame 62, you will see that the plate slides out from where it should be as indicated by the green arrows.) At frame 92, the plate is back into position.
Again at frame 96, the plate is not aligned but back at the end of the animation F100, the plate aligns again. So it's off and on but not usable in a project where for example screen elements may need to be swapped out in composite.
I suspect the Octane Camera is the issue but I can't confirm this independently.
I've tried everything from constraining the plate to the original animation, attaching it via xpresso and baking the animation frame-by-frame to no good result.
Simply put, Octane doesn't seem to work with the C4D's external compositing tag.
Currently, I'm on a workstation at Powerhouse VFX that works in movies and television and I was the one who urged the VFX supervisors to give Octane a try. This is turning out to be a huge embarassment for me that we're stuck in this part of the process.
The Workstation I'm on is as follows:
Windows 10 64bit
Nvidia RTX 2080 TI
128 GB RAM
NVIDIA Driver 18.104.22.16886 (5/22/19)
Cinema 4D R21.026 (Build RB290015)
Octane Render Enterprise 2019.1 version:6000100 SDK:2019.1
Octane Render for C4D 2019.1 built for: 210 C4D vers: 21026
I am attaching the C4D file to this post. If you render out a basic pass in Octane, and then try to get the External Compositing tags - or even the original Geo used in the C4D project. It will NOT line up with Octanes Render.
Thank you and respectfully,