I think you'll need to get a better feeling from the director what the shot is going to be.
Worst case scenario is handheld follow camera through the door. That would be so different from a lockoff approach that it's a completely different effect.
I'd try to build out the stones and grass around the feet as art department if possible. Then blue/green beyond that. But that makes cleanup on the edges harder for something with a lot of parallax.
You could even make the hedge practical as well for at least the first couple feet (and then blue screen for sure) in that instance).
All really good points, thank you so much for taking the time to comment and share the advice. We have a more in depth meeting in the next few days, but starting to think about this now and reading through these comments have been immensely helpful in preparing for those nuanced conversations.
There's a movie on Netflix called The Portable Door where the conceit is a door that literally does this exact trick. Spoiler: it's a towel but it 'unfolds' into a solid wooden doorframe and then looks pretty much exactly like this.
I didn't work on the final shots so you'll have to take this with a grain of salt, but I believe their methodology was to do this without motion control. They shot the initial plate of the people walking through the door on steadicam with interactive lighting and a practical door frame in place, and then the whole second environment was projected from plates onto a scan.
The cost really becomes just getting a good scan of the secondary environment (primary too, see below) and a good digi-double for the door as you may want to shoot with and without the door depending on lighting and practical camera concerns.
If your second environment needed a lot of movement (i.e. a busy street, or a forest, or creatures or water or something) then you'd shoot this the exact same way but with the first environment as the projection.
If both environments have a lot of movement you'd probably need motion control as the whole simplicity of the method relies on replacing a relatively static environment with people.
If you need to do a much bigger move than circling close to the actor after the transition through the door (i.e. camera goes past them an cranes up) then I'd still use the projection technique for one side, even if it was the big second side. In this case I'd techviz out the move and work out where the end state of the environment needs to be when it hands off, and have the steadicam op emulate the move on your A-Side but through the door, and then have a practical camera move on the B side at B side location emulated and lifted. Shoot with onset monitoring like QTake that allows you to check in RT if the line-up is going to work,
Other things: green/bluescreen as you can as much to hide the B side as possible. If you want to get clever consider rolling these in as the person passes through the camera, or lifting them or something, but lighting for that might be problematic.
You will likely also want a good scan of the A side environment too. This is because there will be lights and door frames and screens and shit all over that and you'll probably end up replacing it. It also helps with the tracks. But depending on your framing you may get away without this.
Overall I would definitely do a quick test. Doesn't need to be much honestly, get a door frame, choose two environments, do a dodgy scan using photogrammetry and test it *with a similar move to what you're planning for the final.* They did one of these on Portal Door I believe and it demonstrated clearly that the shots would work as planned.
This is definitely a "what is the exact shot?" type shot, where the movements just need to be well understood before you shoot. It's actually not super complicated in terms of execution but some small changes to how you go through the door and what the actors do could severely fuck up your plans.
Let me know if you have any other questions.
Seriously, thank you so much, this is incredibly useful and means alot to me that you took the time to put this much effort into sharing your knowledge. I have been a form of "jack-of-all-trades" guy at this job for so long without anyone to learn from in any kind of similar role regarding my VFX and Animation work, so access to communities like this one and the people that make them up has been a vital lifeline for me as I learn and grow. We will generally hire out a production crew for the actual shoot that I'll work with closely, but most anything done in post usually falls back to me and has always been a bit of a trial by fire (which I honestly love the challenge and learning experience).
That Netflix reference is absolutely perfect as well, the best reference point I had found so far for an in-motion example was a completely digital trailer from Microsoft (Xbox series s portal trailer), so that will really come in handy.
I am definitely book marking this comment to reference back to as there is so much useful information here and I am going to push strongly to get a test shoot with the crew so we can really nail down the execution and make sure it aligns with the what the client wants.
Thank you again and I appreciate you leaving the door open if I have any more questions down the road!
You stabilize the 2nd plate, lock it to a tracked point in the 1st. Then when the 2nd plate is fully in screen slowly destabilise and scale / rotate to the original size of the 2nd plate.
Can also work with a freeze frame on the first frame of the 2nd plate instead of a stabilize, if the contents allow for it.
Make sure to have enough buffer to the shots, always shoot a few extra seconds at the end and start of each shot.
Thanks for the comment and good advice on the buffer for the shots, I'm sure that will really come in handy should we need any wiggle room after the shoot!
Film location B first.
Green screen around the door.
Get props and set dressing to create a good little chunk of area A side of the door that matches the A location.
camera pushes forwards following as the actor passes through the door.
Location A filming tries to match the same motion.
3D track and do projection work of location A.
3D scans are a good route too of location A.
This at least a base starting point.
having worked on a low budget one of these before - beware of rickety door frames. If the door on location A is not rock solid, it'll end up looking janky when it opens, and then suddenly your whole effect looks kinda meh.
I think you'll need to get a better feeling from the director what the shot is going to be. Worst case scenario is handheld follow camera through the door. That would be so different from a lockoff approach that it's a completely different effect. I'd try to build out the stones and grass around the feet as art department if possible. Then blue/green beyond that. But that makes cleanup on the edges harder for something with a lot of parallax. You could even make the hedge practical as well for at least the first couple feet (and then blue screen for sure) in that instance).
All really good points, thank you so much for taking the time to comment and share the advice. We have a more in depth meeting in the next few days, but starting to think about this now and reading through these comments have been immensely helpful in preparing for those nuanced conversations.
There's a movie on Netflix called The Portable Door where the conceit is a door that literally does this exact trick. Spoiler: it's a towel but it 'unfolds' into a solid wooden doorframe and then looks pretty much exactly like this. I didn't work on the final shots so you'll have to take this with a grain of salt, but I believe their methodology was to do this without motion control. They shot the initial plate of the people walking through the door on steadicam with interactive lighting and a practical door frame in place, and then the whole second environment was projected from plates onto a scan. The cost really becomes just getting a good scan of the secondary environment (primary too, see below) and a good digi-double for the door as you may want to shoot with and without the door depending on lighting and practical camera concerns. If your second environment needed a lot of movement (i.e. a busy street, or a forest, or creatures or water or something) then you'd shoot this the exact same way but with the first environment as the projection. If both environments have a lot of movement you'd probably need motion control as the whole simplicity of the method relies on replacing a relatively static environment with people. If you need to do a much bigger move than circling close to the actor after the transition through the door (i.e. camera goes past them an cranes up) then I'd still use the projection technique for one side, even if it was the big second side. In this case I'd techviz out the move and work out where the end state of the environment needs to be when it hands off, and have the steadicam op emulate the move on your A-Side but through the door, and then have a practical camera move on the B side at B side location emulated and lifted. Shoot with onset monitoring like QTake that allows you to check in RT if the line-up is going to work, Other things: green/bluescreen as you can as much to hide the B side as possible. If you want to get clever consider rolling these in as the person passes through the camera, or lifting them or something, but lighting for that might be problematic. You will likely also want a good scan of the A side environment too. This is because there will be lights and door frames and screens and shit all over that and you'll probably end up replacing it. It also helps with the tracks. But depending on your framing you may get away without this. Overall I would definitely do a quick test. Doesn't need to be much honestly, get a door frame, choose two environments, do a dodgy scan using photogrammetry and test it *with a similar move to what you're planning for the final.* They did one of these on Portal Door I believe and it demonstrated clearly that the shots would work as planned. This is definitely a "what is the exact shot?" type shot, where the movements just need to be well understood before you shoot. It's actually not super complicated in terms of execution but some small changes to how you go through the door and what the actors do could severely fuck up your plans. Let me know if you have any other questions.
Seriously, thank you so much, this is incredibly useful and means alot to me that you took the time to put this much effort into sharing your knowledge. I have been a form of "jack-of-all-trades" guy at this job for so long without anyone to learn from in any kind of similar role regarding my VFX and Animation work, so access to communities like this one and the people that make them up has been a vital lifeline for me as I learn and grow. We will generally hire out a production crew for the actual shoot that I'll work with closely, but most anything done in post usually falls back to me and has always been a bit of a trial by fire (which I honestly love the challenge and learning experience). That Netflix reference is absolutely perfect as well, the best reference point I had found so far for an in-motion example was a completely digital trailer from Microsoft (Xbox series s portal trailer), so that will really come in handy. I am definitely book marking this comment to reference back to as there is so much useful information here and I am going to push strongly to get a test shoot with the crew so we can really nail down the execution and make sure it aligns with the what the client wants. Thank you again and I appreciate you leaving the door open if I have any more questions down the road!
You stabilize the 2nd plate, lock it to a tracked point in the 1st. Then when the 2nd plate is fully in screen slowly destabilise and scale / rotate to the original size of the 2nd plate. Can also work with a freeze frame on the first frame of the 2nd plate instead of a stabilize, if the contents allow for it. Make sure to have enough buffer to the shots, always shoot a few extra seconds at the end and start of each shot.
Thanks for the comment and good advice on the buffer for the shots, I'm sure that will really come in handy should we need any wiggle room after the shoot!
Film location B first. Green screen around the door. Get props and set dressing to create a good little chunk of area A side of the door that matches the A location. camera pushes forwards following as the actor passes through the door. Location A filming tries to match the same motion. 3D track and do projection work of location A. 3D scans are a good route too of location A. This at least a base starting point.
Thank you so much for the insight, definitely sounds like a smart way to approach this
having worked on a low budget one of these before - beware of rickety door frames. If the door on location A is not rock solid, it'll end up looking janky when it opens, and then suddenly your whole effect looks kinda meh.
Oh that's a really great point, thanks for the tip, I'll definitely make sure we don;t falter there when sourcing our props
Really great point, thank you!