my 2DOF +/-30 degrees tilting chair mosim

thanks. i like FSX for one big reason, i wrote a really cool mission, an air race around yosemite park in an extra300 aero plane. problem is, FSX doesn't run in VR without that flyinside addon thing right? i tried it a while ago and was not impressed with the graphics, maybe its better now. how is prepar3d and VR?

i guess not good https://www.reddit.com/r/oculus/comments/3na3mb/how_is_the_native_oculus_mode_of_prepar3d_v3/
seems like flyinside is the only way to go at the moment

i'll make another video later showing the details and how i configured it all

notice that the oculus sensor is fixed to the rig and its working perfectly, my VR view is spot on, no weird effects at all, really feels like in in the real world in there

UPDATE:

so i've had a bit of time to fly around and a couple of things i notice. first off, awesome! well worth the effort to build this thing.

i'm flying my vegas air race which i made a video about a while ago


you can see on the mosim video, when i go vertical climb, at some point the roll starts reacting strange. i'm sure this is DCS that's detecting roll in a near vertical is not very specific, but the motion sim doesn't know that, so it shakes me around, which isn't very realistic.

however, when i come over the top of the loop and pull a positive G to head straight down, it feels very realistic, so overall, pretty good.

the other thing is when i'm doing a tight banking turn, the mosim is banking (rolling) as its supposed to, but in real life of course, you wouldn't feel that, you would feel g forces pushing you down hard into the seat.

now obviously, i have no way to simulate 5 G of downward force, so i guess there is no answer for this problem.

just wonder if any setup advice? maybe instead of using roll in the axis assignment, i use something else?

and the other thing is, you know if you've been on a boat for a while and you get on dry land and you feel like you are still moving? we'll i'm sitting at my desk now and i feel like i'm still flying!

UPDATE, i fixed these issues here
https://www.xsimulator.net/communit...s-tilting-chair-mosim.9181/page-3#post-118497

i like the range of travel especially on the pitch axis, when you are heading straight up or down it feels very realistic.

roll doesn't feel as realistic as i mentioned above, and is also a bit uncomfortable. but its not so much that i need the seat belt i put on there, turns out that was a bit of overkill.

also, no motion slickness at all, but i'm usually ok with DCS anyhow, i guess i'm just used to it in VR.

i got a steering wheel and dirt rally a couple of weeks ago but after 5 mins of play i'm usually sick as a dog. can't really say i enjoy it in VR to be honest, but i guess my next trick is to mount the wheel to the mosim and see how that feels.

i just tried smoothing, the thing is, in normal flight with pitch less than +/- 45 degrees it feels great already without smoothing. the problem seems to kick in at extreme pitch angles of about +/- 60 deg pitch and above (i mean airplane pitch, obviously the sim can't do that).

is there a way to smooth or limit the roll axis only when the pitch is in the extreme range?

i could probably mod the exports.lua file that gets installed by the DCS pluging, but it would be easier if there was a configuration options somewhere

It is impressive to see the result of the angles taken

i just spent some time on that but i'm not sure its what i want.

anyhow, i ended up modding the export.lua from the original plugin and so far i'm happy with the results

i added the following lines

if pitch > 30/57.295779 then
bank = bank*0.5
elseif pitch > 60/57.295779 then
bank = 0
end

right after local pitch, bank, yaw = LoGetADIPitchBankYaw() in AfterNextFrame

the effect is to reduce roll by half above 30 degree pitch and remove roll all together above 60 degree pitch

it improves the feeling when going into a vertical climb

anyhow, i have more stuff to try but i have to go work on my paying job for a while so back later

steve

hi everybody, i've fixed all the jumping and jerking around problems at extreme pitch and roll (for DCS)

if you want to try it, install the standard DCS plugin, not the one from riftflyer, then go to your DCS scripts directory, mine is at C:\Users\me\Saved Games\DCS.openalpha\Scripts

exit your export.lua and change the body of AfterNextFrame to this

*******************************
AfterNextFrame=function(self)

local altRad = LoGetAltitudeAboveGroundLevel()
local pitch, roll, yaw = LoGetADIPitchBankYaw()
local accel = LoGetAccelerationUnits()

-- convert to degrees to make the math easier
pitch = pitch * 57.295779;
roll = roll * 57.295779;

--dbg_file:write(string.format( "p=%.1f r=%.1f ", pitch, roll))

-- STEVE reduce roll by when pitch > 45deg
if pitch > 45 then
local multiplier = 1- (pitch-45)/30
if multiplier < 0 then
multiplier = 0;
end
roll = roll*multiplier
--dbg_file:write(string.format("PITCH>45: p=%.1f r=%.1f m=%.3f ", pitch, roll, multiplier))
end

-- STEVE returns roll back to zero as it passes +/- 90 degrees to avoiding the -179 to 179 flip that occurs in a full roll
if roll > 90 then
roll = 180 - roll
--dbg_file:write(string.format("ROLL>90: p=%.1f r=%.1f ", pitch, roll))
elseif roll < -90 then
roll = -(180 + roll)
--dbg_file:write(string.format("ROLL<-90: p=%.1f r=%.1f ", pitch, roll))
end

--dbg_file:write(string.format("\n"))

-- reduce forces on ground
if altRad < 3 then
accel.x = accel.x * 0.25
accel.y = accel.y * 0.25
accel.z = accel.z * 0.25
end

my_send = socket.protect(function()
if c then
-- socket.try(c1:send(string.format("%.3f; %.3f; %.3f; %.3f; %.3f; %.3f;\n", pitch*1000.0, bank*1000.0, yaw*1000.0, accel.x*1000.0, accel.y*1000.0, accel.z*1000.0)))
socket.try(c:send(string.format("%.4f; %.4f; %.4f; %.4f; %.4f; %.4f;\n", pitch/57.295779, roll/57.295779, yaw, accel.x, accel.y, accel.z)))

end
end)
my_send()

end,

*******************************

if you want to run the debug printouts, add this to the Start function
dbg_file = io.open(lfs.writedir()..[[Logs\dbg.txt]], "w")
dbg_file:write(string.format("start ok\n"))

so what this does, is when pitch goes over 45 degrees it attenuates the roll factor, which as you can see from the log file below, goes a bit nuts when pitch is over 60+ degrees. this makes vertical climbs and loops much smoother

then the next bit fixes the flip that occurs when doing a 360 degree rolls. when roll goes past +/- 90 deg, it rolls it back to zero at 180, so there is a smooth transition from +179 to -179 deg

with a VR headset on, both fixes feel quite natural. i've done about 40 hours of aerobatic flying in real life so i have an idea how it feels, and this feels pretty good (- the G forces. maybe my next fix, a G seat)



in the axis setup in game engine i originally limited the pitch and roll scaling at 40% because of those extreme pitch and roll jerky issues, but now that its much smoother, i can use 60%, so i get a bit more range and aggressiveness than that video now

i just added the .lua file here but because i can't upload .lua files i called it .lua.txt. to use this, change your export.lua to export.bak or whatever then change export.lua.txt to exports.lua

this is a major improvement over the standard DCS plugin

here is the description of how i built it and set it up


its working great now so time for some flying, until my next project!

most of the build time was waiting for china post, and most of that, the Arduino board. i would say the mechanical work was about 4 days, the electronics, 1/2 a day and software setup and tuning, 2 days.

of course, had i seen my video before had, i could have cut that in half

steve

hi, i'm back, my sim is running fine but i've noticed one motor has a lot of play in the worm drive. this is powered down, not connected to anything, i can wiggle the shaft about 10 degrees with almost no resistance before i feel the torque from the worm drive. my other motor doesn't do that at all.

do you think it a manufacturing problem or something i maybe did? it should be resilient to been driven against a dead stop (which happened a few times during set up) right?

https://www.motiondynamics.com.au/worm-drive-motor-12v-24v-200w-180-rpm-20nm-torque.html

ok, thanks, i'll open it when i have time. i contacted the supplier but they basically said 'fair dinkum mate', i think that means shit happens

Hi SteveH, I installed your export.lua in my DCS saved games script folder, but I am still getting jerky motion when flying in DCS 2.1. Do you have any other tips for fixing this issue?

Not sure if it is a axis setting issue, filter issue, or .lua

Thanks for any help!

Man I cannot thank you enough! I have been searching all over to find a workable plugin for DCS that doesn't throw me out of the seat when I roll or loop! I used your export.lua you posted and it's great. I still have no YAW, were you able to make that work?

Hi, this so far looks like the simplest recipe for simple and cheap MSFS motion platform that I want to build. Is it still working? Did you make it work with MSFS? Do you know if it would work with WMR (what about motion compensation?) Would you do anything differently, now that you have experience with it? How much approximately did all the parts cost together? Thanks.