(Resolved - user error) Yaw issue with DCS plugin and G-Seat

I've been playing around with sim tools all evening and have come across an issue with yaw in this plugin. Perhaps somebody could help.

I'm testing with a helicopter and have the yaw setup on the two actuators on my backrest. As I turn in a hover the yaw pressure increases continuously unitl it hits the limit and then the actuators quickly zero. It's as if the yaw value is based on intial heading and are referencing the compass rather than an aerodynamic force.

Has anyone experienced this?

Thanks @noorbeast I'll read up on the filters. I understand why the need for reversing on pitch and roll as you pass 180degrees as the gravity vector changes. In yaw that doesn't happen. In a constant pirouette in a helicopter the force should be relative to the rate of change in the yaw axis. The force doesn't flip after turning 180 degrees as unlike pitch and roll the gravity vector is constant. Is this limitation of Sim Tools something that can be overcome?

I will experiment further with yaw today. If this is a software limitation then I'm surprised nobody else spoke of it in the dcs plugin section.

Yaw/pitch/roll are not forces, but are changes in orientation due to Rotation - the forces related to these changes/'Translations' in orientation are called sway/surge/heave. Yaw/pitch/roll is therefore purely based on a change in heading on these three axis's and has limitations as you have found in simtools. You could get around these limitation by writing suitable code in your controller if you are building a 360 degree capable sim - but most don't need or use it. Hope that helps.

@SeatTime i have no need for 360 degree code. I'm building a gseat. Should I therefore use sway instead of yaw to achieve a constant pressure while performing a pirouetting maneuver?

Thanks @noorbeast and @SeatTime

I've completed a modification to my backrest and will try with sway once I get everything reinstalled.

Agree with @noorbeast , I actually don't use yaw at all and barely any roll/pitch (depends on game/vehicle), as I find it can distort what I should be feeling, especially with the Rift.

Although don't forget that for example a yaw is not always purely a sway (although mostly), as there may be a surge component, or even a small heave force generated. It is why creating a good profile can take some time as it can be a mix of all forces for most axis's.

Thanks @SeatTime

My plan for now is to leave out yaw and try sway on the backrest. I will then experiment with surge. Unlike yaw pitch seemed to be working quite well but I haven't spent much time going inverted in a helicopter!

I've yet to complete the base of the seat where I will have heave.

So for the rift do you think that heave/sway for the base and surge/sway for the backrest may yield the best results?

Ok the official plugin here http://www.xsimulator.net/community/marketplace/digital-combat-simulator-–-dcs-plugin.16/ has sway acting as heave. Time to do some more thread searching.

You might get together with @hugso he has a great deal of experience with DCS in his project. I know what you mean as I ran into it with my 6DoF project but have never looked further into it.

Thanks @Historiker. I sent @hugso a message but he has not used DCS in a long time. I managed to find another version of the DCS plugin which does not have heave mixed up with sway. Unfortunately the resulting sway force is not working as expected when used as a substitute for yaw. I am currently uploading a video of a tuning flight I saved in the Rift and the associated tuning centre view. This should clearly illustrate the issues I'm having with sideways and pirouetting flight.

I believe the plugin needs another value in order to simulate the forces associated with these phases of flight. Those familiar with aviation will know of the turn and bank indicator which is one of the basic six flight instruments. It will indicate when the aircraft is in a slip or slide. It can be called by "local slipball = LoGetSlipBallPosition()" in the eport.lua file. If this value could be added as an extra force in the plugin I think it may resolve my issues.

As suggested I also tried surge in place of pitch. The effect actually doesnt work too well in a helicopter. As the helicopter accelerates it adopts a nose down attitude which should result in a lowering of pressure from the rear of the seat. The usual surge force would be therefore inverted. I ended up reverting to pitch. Now that I think of it I could try it with the output reversed. Not sure if that will cause issues with other phases of flight though.

I'll post a link to my tuning video once it is uploaded.

I'm enjoying the DCS plug in but would love the roll and yaw 180 degree to be sorted

So it flips as soon as 180 degree is passed, I think its possible because the pitch does it perfect

@Adrianstealth the roll, pitch and yaw values are rotations measured in degrees. For forces you should experiment with sway, surge and heave. I made this error initially and that is why this thread exists. As you can see above I was corrected.

As stated in the other thread Sway is actually outputting Heave. Surge is correct but the output from heave which I'd expect to be sway (given the other error) seems to be incorrect.

I have completed a function to call the value of the slip ball and assign it as an extra variable to be passed to SimTools. Unfortunately, I am unable to compile a new plugin from the source code provided to me by @value1. I am not a programmer so I can't tell what I'm doing wrong. I can build a new .dll but when I patch it says not a valid plugin. It also throws a debug error even without me modifying anything! On Friday I sent @value1 a modified export.lua along with a copy of the function and a note regarding the heave/sway mix up in the hope he can compile a new plugin. Fingers crossed he can review the plugin, make changes or perhaps advise me on what I'm doing wrong with the source code he provided.

Riftflyer

Ok Brill a big thanks for your efforts on this & its great you share

The sway and heave is fine (I know the name mix up but that's minor )

Its the roll 180 degree flip ( actuators quickly moving to other side to follow aircraft angle )
The pitch handles it great and correctly ( actuators simply follow in reverse at 180 degree point )

Thus the roll effect is unusable even with all the extra setting combinations

Be really great if roll could work as the pitch does, I'm not using roll at all sue to this

With pitch doing loop the loops feels Brill

Not moaning at you, wish I knew how to do make these plug-in's myself but zero knowledge

I've managed to compile the modified plugin and get it working with the added slipball force. I've tested it and it works well. I wanted it for helicopters but it also gives good effects on my G-Seat in fixed wing aircraft.

Taxiing the p51 now provides good lateral forces when turning due to the tail wheel steering and a lateral force during uncoordinated flight when in a slip or slide. Big thanks to @value1 for allowing me work with his source code.

@Adrianstealth an alternative to roll (which I find is working as it should) could be to use stick position to output a force. This would be of no use to me in helicopters as control stick position does not correspond to aircraft attitude but it could work with the old warbirds. Instead of roll you could read the X axis aileron control and output a corresponding force based on the amount of deflection. I may look into this after I make a little more progress on my seat. I've been buried in code for too long and need to get back to building!

Hi @RiftFlyer, can you share your new plugin with us? I would like to try it out myself as soon as my own g-seat is finished. I have my heave mechanism done (and working well).

thanks for update rift

I'll hold out until update with non flip roll if this comes

I think stick forces may seem canned to me compared to making the best of physics based forces

is valve1 intending to do further work on this plugin I wonder?

anyhow thanks for doing what you can rift flyer


ps flip at 180 degrees I think would be fine in a g-seat, but it's awful on a seat rocker type setup such as mine )-:

I have PM'd valve1 to see if a fix can be done , even a roll that behaves like the pitch at 180 degrees can be put on extra1 so people can choose etc