Well just one example for Rift + LFS + motion chair.
Let's say you are driving up a 20 degree slope at constant speed. Your chair, and steering wheel, should lean back 20 degrees.
Now, if you look "forward" with your head relative to the car body (as if you were a stiff crash test dummy) your head will be looking UP 20 degrees relative to the real world. So the Rift camera, regardless of whether it is mounted on the seat on on a nearby tripod, will think you are looking UP 20 degrees. So now, the way LFS + Rift works at the moment, your view will be pitched up 20 degrees relative to the car. And that will be UP 40 degrees relative to the in-game world, which is wrong. So although your head doesn't move relative to the steering wheel, you would now have to look down 20 degrees (i.e. move your head to be level relative to the real world) to see it as it is supposed to be.
EDIT: It seems to me the Rift camera should be mounted on the same platform as the seat and wheel so that it can detect your x, y, z movements correctly, but I imagine vibrations affecting the camera. Anyway, if the vibrations aren't a problem, can't LFS solve this problem by showing the view relative to the horizontal plane? So in the example above, the in-game viewpoint would use the YAW of the car but not PITCH and ROLL, in a special "motion simulator type 1" mode? Adding the pitch and roll of the actual headset, so your view is once again aligned with the car body? Though this will only work if the motion seat pitch and roll matches the in-game car pitch and roll exactly (and doesn't allow for extra pitch and roll often added by motion simulators in an attempt to recreate acceleration forces).
Or will there be a problem as the in-game car tilts to go up the hill but the motion chair has lag in its response...? Or are there still more problems, as when you tilt back the camera goes higher than you, so the Rift drivers think you have got lower in your seat...?
Either way, these problems could be solved by the Rift drivers themselves, if indeed they know the pitch and roll of the motion chair, by use of an additional hardware device mounted on the chair and doing a subtraction as mentioned by sinbad:
https://www.lfsforum.net/showt ... php?p=1869220#post1869220
Let's say you are driving up a 20 degree slope at constant speed. Your chair, and steering wheel, should lean back 20 degrees.
Now, if you look "forward" with your head relative to the car body (as if you were a stiff crash test dummy) your head will be looking UP 20 degrees relative to the real world. So the Rift camera, regardless of whether it is mounted on the seat on on a nearby tripod, will think you are looking UP 20 degrees. So now, the way LFS + Rift works at the moment, your view will be pitched up 20 degrees relative to the car. And that will be UP 40 degrees relative to the in-game world, which is wrong. So although your head doesn't move relative to the steering wheel, you would now have to look down 20 degrees (i.e. move your head to be level relative to the real world) to see it as it is supposed to be.
EDIT: It seems to me the Rift camera should be mounted on the same platform as the seat and wheel so that it can detect your x, y, z movements correctly, but I imagine vibrations affecting the camera. Anyway, if the vibrations aren't a problem, can't LFS solve this problem by showing the view relative to the horizontal plane? So in the example above, the in-game viewpoint would use the YAW of the car but not PITCH and ROLL, in a special "motion simulator type 1" mode? Adding the pitch and roll of the actual headset, so your view is once again aligned with the car body? Though this will only work if the motion seat pitch and roll matches the in-game car pitch and roll exactly (and doesn't allow for extra pitch and roll often added by motion simulators in an attempt to recreate acceleration forces).
Or will there be a problem as the in-game car tilts to go up the hill but the motion chair has lag in its response...? Or are there still more problems, as when you tilt back the camera goes higher than you, so the Rift drivers think you have got lower in your seat...?
Either way, these problems could be solved by the Rift drivers themselves, if indeed they know the pitch and roll of the motion chair, by use of an additional hardware device mounted on the chair and doing a subtraction as mentioned by sinbad:
https://www.lfsforum.net/showt ... php?p=1869220#post1869220