One complaint we hear a lot from tech support is that the 747 knobs are hard to control in the 3-d cockpit.  Javier and I did some investigation into this; this post describes what we found, what we are changing, and what why I don’t think the scroll wheel probably shouldn’t be used to affect the 3-d cockpit.

Hard To Drag

The fundamental problem is that it’s hard to control the autopilot knobs in the 747 by dragging with the mouse.  Large drags make only a small change in the knob, so it takes forever to dial in an autopilot altitude.  You’d think the solution is simple: change the scale for dragging on the knobs, right?  Well, not quite.

It turns out that the “sensitivity” of the knobs to dragging is a function of the way you turn your head in the cockpit.  Sit in the default 3-d position, turn your head 30 degrees to the right and drag and the knobs turn quickly.  But look straight ahead, slide to your right, and drag and they are very slow.

The problem is one of perspective, and this is where it gets interesting for authors.  The drag axis manipulator (which lets you make the 3-d cockpit respond to dragging the mouse) measures its drag in meters.  But the distance on the screen that the drag distance takes up (in meters) depends on where the camera is placed and at what angle it is turned.  This can lead to some very strange effects: in some views, a 500 pixel drag moves the altimeter only a few hundred feet, while in other views, 500 pixels moves tens of thousands of feet.

Screen Space Dragging

For real physical parts like a lever (a part that moves as you drag it), dragging in meters makes perfect sense; it lets authors match their animations to their manipulations.

But for a drag that doesn’t have a real-world correlation (e.g. you drag on the knob and the knob spins but it doesn’t move) having the camera angle affect the drag distance results in panels that can be used only from certain viewpoints.

To fix this, we are introducing a new “pixel” drag axis – unlike the current drag axis, the distance over which the user can drag is specified in pixels, so that the “sensitivity” to the mouse is the same no matter what view angle the user has.  I will post details on this when we go beta.

The Mouse Wheel

While I was working on pixel drag axis, I looked at using the mouse wheel to turn knobs, something our users asked for.  And while the prototype seemed ‘clever’, after some arguments with Chris I came to a bit of an inescapable conclusion: the mouse wheel for changing parts of the panel is the wrong tool for the job.

The problem with the wheel is that in the rest of the universe it is use to manipulate view information.  This is true in X-Plane 10.05 as well (and it works well), but things get quite tricky once the mouse wheel is added in.  Some of the problems:

  • Making the mouse wheel zoom and manipulate (e.g. if you are over a knob it manipulates the knob, otherwise it zooms) risks surprising results.  A user who wants to zoom might accidentally “bump” a cockpit knob, something that’s pretty frightening to a real pilot.
  • We looked at requiring once of the buttons to be held down while mouse-wheeling, but that’s not a gesture you see anywhere else in the universe – effectively one of the two uses of the wheel is “buried” and we might as well only use the other.  Furthermore, if we are going to require a click, the user might as well just drag on the knob itself.
  • If we have to pick one or the other (zoom or manipulate), zoom is by far the most consistent thing, the thing that fits with the host OS.
  • If we make the option a preference (e.g optional mouse-wheel on knobs) so few users will enable it that authors won’t be consistent in adding support to their cockpits, and the system will never get momentum.  (We can’t just add “mouse wheel automatically” because the sim doesn’t know how much one click of the wheel should change a given dataref.)

We tossed the mouse wheel idea around, but in the end we concluded that the wheel should be a view/zoom/scroll function, not a data change function – we couldn’t find any example apps that used the wheel to change the contents of the screen.  In the end, authors need to make clicking work well, and we need to provide manipulators (like the screen-space drag manipulator) to make that possible.

About Ben Supnik

Ben is a software engineer who works on X-Plane; he spends most of his days drinking coffee and swearing at the computer -- sometimes at the same time.

78 comments on “Manipulators and the Scroll Wheel

  1. I think you should make the mouse wheel turn knobs. And for zooming, one could use Alt+ Scroll wheel. That is used in many programs (for example Photoshop) and would make sense. You can’t accidentally change the position of a knob or lever, because you would have to hold the alt key. So, that problem is resolved. And I don’t think, the function would be buried. Users will find help in forums, or they will read the manual.

    1. Requiring a user to search through forums (or even reading a manual, damn kids those days) is hiding the function.

      Adobe’s Lightroom uses the wheel to change slider values, but at least on PC the functionality is integrated in such an ugly way (you have to click on the text field and then you get to “scroll” that in some way or another, with pretty much random granularity) that I rather spend a few extra seconds placing a slider on the pixel-exact spot were I need it or enter the proper value into the text field right away.

      Speaking of which, wouldn’t it make a lot of sense to have UI pop-ups for some instruments where a user can just enter the desired value? There are significant differences in usability between a computer and an airplane, and at some point even a simulation should cater to them. The real enthusiasts buy plug-in radio stacks and all the other fancy hardware anyway for maximum realism.

      1. I have to admit that _personally_ UI popups appeal to me; when I used to fly (300 years ago) using XSquawkBox, before I got GF radio stacks, I would always change frequency by typing //freq in the text box – it was the lesser of two evils (the other being to use the mouse). And that was in 2-d.

        It wouldn’t be the most immersive thing though; the one really strong case for keyboard entry I can think of is the FMC keypad.

  2. Why FSX/FS2004 can make this real to change data with the Mousewheel?
    Where is the different? Is this a OpenGL based failure?

    1. No. This has nothing to do with OpenGL. I am saying that we _can_ use the mouse wheel to change the panel but it is bad UI design.

      1. It works great in FSX and FS2004. Works great meaning after 500+ hours of flying high end payware, I found it to be the best way to rotate knobs, and dial in autopilot information.
        I just hover over something i want to change and use the mouse wheel. It is a whole lot easier to and setup then this mouse drag stuff which as a develop, i hate. I specifically used Toggle switches as much as I could because of it.

        Another way I have seen it done is how PMDG has it setup in FSX. The left and right mouse buttons turns the knobs one way or the other.

        The click and drag just doesn’t work well at all. if i don’t have enough screen to get to the alt i want to select i have to scroll back down to the knob and scroll again and again until I have what I want.

        1. With 1000 pixels on screen at lowest res, I tend to think that if you can’t make your adjustment in one drag, it’s an authoring error – a poorly scaled knob.

          1. The problem here is that in the virtual cockpit, the knob can happen to be (or it has to be) close to the screen side. So if you need to rotate the knob to that side, there will be simply no space to drag. It’s not about resolution. Otherwise you will have to always try to position your knob at the center of the screen which is not always possible, as in some planes you have to see the numbers at PFD while you rotate an autopilot altitude knob for example…
            I believe, the mouse click on the sides of the knobs should is working great on those FSX
            Another option is to rotate knobs with mouse wheel and to hold a key (or even better – mouse wheel) to use mouse wheel for zooming.

          2. Yes well, like Dmitry pointed out, the knobs are not awlays at the edge of the screen. To go from Zero ATL SELECT, to FL350 in 10 foot incriments you need 3500 pixels to get it right. To add to this now i have customers telling me they cant get the the value right now the 35000 mark but end up a little high or low.
            If i set it to only manipulate by 100s and not 10s, i get customers saying the same thing because the Sim started them out somehow at a number between 100 and 200, and now they cant get that fixed and are stuck the whole flight not exactly at the alt they wanted.
            I also hear from customers that they just cant diel in the exact number they want without really concentrating on their mouses position.

            What i wound up doing to solve this is to use as few screen space manipulators as i could and where i had to use them, say for the ATL, i added invisible push buttons to the sides of the knob to allow for 10 foot increments to make fine tuning easier.

            All this extra work, fixing dragging manipulators makes my work harder. I wished and wished that you would add in some kind of mouse scroll wheel support eventually. I was really happy when you made the change to it being used for zoom.
            Right now you have it setup as the left mouse button pans, you can also set up that to zoom as well when pressed.
            In FSX, you have to hold space bar to zoom and pan with the mouse, and when depressed you can manipulate with the mouse, both left and right buttons and scroll wheel.
            It has worked for years like that. It is what most FSX users expect to have happen when switching to X-Plane. It is also what I as a developer would find most helpful.

        2. I agree with you. Another greate example is DCS series (A-10C and Ka-50 Black Shark).
          In DCS series mouse is used to it’s 150%.
          The developers are using left and right mouse buttons as well the mouse wheel to manipulate controls in virtual cockpit.
          They are using mouse wheel for zooming and panning too.
          i.e.: //

  3. I agree with Chris, the mouse wheel should turn knobs and Zoom should be assigned to something else, ALT-Mousewheel or something similar.

    Mousewheel to turn a knob just makes sense, and I bleive would be used far more than Zoom functionality.

  4. Hey Ben, thank you for the fast reply.

    Sorry for my bad english :3

    What do u mean whit “bad UI design”?

    And is it possible to hold the mouse over the Altitude Knob and press and hold the left mouseKey for increase the Altitude and the right mouseKey for decrease it?

    Dragging is very troublesome generally for the Speed… i need many time to set the Speed at 315Kias. i drag, then im on top of my screen, and select again and drag again,…

  5. Damn, and to think I just bought a new twenty foot desk for my mac for the sole purpose of inputting headings and Mach numbers!!

    Hope it’s not going to be wasted Ben;)

  6. “why I don’t think the scroll wheel probably shouldn’t be used to affect the 3-d cockpit.”

    Hmmm, two negatives… So does it mean you think scroll wheel should be used instead? 😛

  7. I’m sorry but I don’t agree with you on this. I rarely use zoom (if ever), but I constantly have to dial in numbers.
    I don’t mind if it is not a default use for the wheel, but please let us users pick if we want to use it for turning knobs or not (as per your fourth option).

  8. I don’t suppose it’s possible that one of the pre-conditions for knob turning is that the mouse wheel is stationary at the point when the cursor comes into contact with the knob?
    That way, if you’re using the mouse wheel to zoom, you avoid ‘bumping’ the knobs in the 3d cockpit as you describe.

  9. I tend to fly only in 2D mode as my TrackIR4 is often misplaced on purpose..
    The one thing that have allways annoyed me in regards to buttons in XP is that I need to switch between keyboard stroke E and down arrow to see a bit of the panels. When I do turn i.e to the left, there is no way to turn the nobs or press any buttons.

    Is this something you can also take a look at while doing the makeover on the 3D nobs and manouvering?

    Last but at least, I want to support Chris above in regards to making the mouse wheel turn the nobs and wheels, this is way to more easy and I have seen and used this in FSX with great success.

  10. I have no (real) mouse wheel, as I use the magic trackpad. It would be a nightmare to dial the values like this.

    Why change a “running system”?

    I think XP10 has some serious and much more obvious issues, wich were already talked about here on the blog but have no solution yet.

  11. The scroll system that I feel works the best is the Carenado version, It scrolls fast east – west and slow north – south or fast left – right and slow north – south, for some reason I find it natural and very easy to tune even with the little bugger bouncing around in windy conditions,
    With out doubt Javier’s is the worst, It is simply impossible to get the Map zoom back out, I have to use the keys to make it work, and to adjust the altitude I pass the mouse over to the C0-Pilot to carry it on around on his side.

    I also agree on the scroll wheel – I have a gesture mouse and it is a real pain in X-Plane certainly on the local map…so i use only the standard 1-click mouser version.

  12. I like the idia of using the mouse wheel turn knobs ! If you need to zoom in and out use a key…

  13. I’m with Ben on this one, 200%. Having to use extra keyboard keys to zoom with the mouse wheel would ruin X-Plane for me. My usage when flying is thus; I am *always* in a 3-D cockpit, one hand on the yolk, the other on the mouse, command look mode. I move the mouse with right button pressed to pan/pivot the view around and wheel to zoom in on some dash/panel components.

    1. Have you considered to buy TrackIR. I am using it for a month now, and it’s just great for doing things like you described only by moving your head. Of course, when you move your head forward, you can zoom in on any part of the panel, then.

      This way it’s much more intuitive and immersive… and you don’t need to use the wheel for zooming… and we can use the mouse wheel for turning the knobs. 😉


  14. If clicking turns the knobs, why when could’nt we just hold the mouse button pressed so that the knobs would keep turning till we released it?

    1. I think the push button manipulator already does that if authors want to go that way. But (unlike MS), right button doesn’t manipulate, it moves the view around.

  15. Hey Ben,

    It’s interesting, but I really would encourage you to rethink the mouse wheel as an input device, and I would directly challenge your notion that it is “bad UI design”. FS9 and FSX both use this feature, and if people are going to be coming over to X-Plane from those platforms, it seems that anything that the developers can do to help make them feel less alienated from their MSFS flying interaction would be a good thing. For me personally, it really took some time for me to adapt to the X-Plane way of doing things, and I still miss pop-up menus and using the scroll wheel for data inputs. For me, the scroll wheel is way easier to use, and is more precise. If I miss an altitude or frequency in one direction, with the mouse wheel, all I have to do is reverse direction. Boom. Done. With the way that X-Plane is setup, and how it seems you want to keep things, I must move the mouse cursor around to find the half circle with the minus sign on it, then click and hold while I am at the mercy of the sim as to how fast it will cycle through the numbers. Then, when I get close, I must release the mouse button and start clicking madly to fine tune the number I want. If I miss the number, then I have to find the clickable hotspot on the other side of the knob to go in the other direction. With the radios it becomes even more tedious trying to move my mouse around to find the bigger or smaller half circle with the appropriate scroll direction (plus or minus) and then click away to set the numbers, hoping that I don’t miss the desired number and have to hunt around for the other desired clickable spot on the other side of the knob to go in the other direction. Put this interface in an online situation on short final where approach sends you over to the tower, and you’re looking at a good chance for a missed approach if you haven’t had the time to pre-set the frequency or muck up tuning it in. The click and drag function is better, but still flawed as you have pointed out in your post. If we were to consider ease of use and amount of time to input a function, then X-Plane has, by example, the worse UI design of the two. This is a part of what makes X-Plane come across as user-unfriendly by MSFS users considering switching over. As far as using the mouse wheel for zooming in, there are keys that do that just fine already. The scroll wheel for zooming is redundant.

    As far as other apps not using the scroll wheel for data input, are you comparing apples to apples? The leading competitor to X-Plane in the Flight Simulator marketplace does in fact actually use the scroll wheel for data input, and people have come to expect it, regardless of whether it is a bad UI design or not. Other non-flightsim programs, such as Photoshop, use the mouse wheel to set data inputs for things like text size and font selection rather than use the drop down menus if desired. The bottom line is that the scroll wheel is the fastest way to enter certain types of information. I’d be curious how you guys came to the conclusion that using the mouse wheel for data input is “bad UI design” and what you are basing that on.

    Ultimately, I doubt making the mouse scroll wheel function an option within X-Plane is really that bad of an idea. I’m not sure I could say for sure how many people would use the function for data input vs. zooming, but I can say that all MSFS users coming over, whatever that number might be, would more than likely use it for data input, just like they did in their old sim.

    Anyway, just my $0.02 worth…


    1. As I said I have no real mousewheel because for X-Plane it was never really necessary. I love the manipulators. They only need to be done good by the developer, like Carenado does.

      Because of MSFS-users new to X-Plane I now need to buy and use a normal mouse to dial my knobs in the sim that I use since many years? I am pretty sure MSFS-user can adopt to such a mini-difference. Some people switch from Windows to OSX, some from GIMP to Photoshop. There always some things different…

      1. Marcus,

        Putting the UI discussion aside, I understand what you’re saying, and yes, people can make the change. The big question is WILL they make the change. Also, it seems from just the comments on this post, that there are more people in favor of the scroll wheel as a knob turning input than there are that would keep it as is. So looking at this discussion (minus the UI discussion), your comment, and what I know about the MSFS crowd (and my own personal preference), is the reason that I support addition of an option that allows the user to select the desired use for the mouse wheel. That way you and those that share your opinion can continue to use the normal mouse clicks to dial your knobs, and myself and those that share my opinion can use the scroll wheel to dial our knobs.

        1. One of the lessons you learn when dealing professionally with the internet, like I do, is that people raise their voice when they have something to complain. I learned not to take such stuff as an actual demographic insight about what users really think.

          fwiw, i’d like to see the energy blown out with stuff like this be better put into building 64-bit, some industrial scenery, and so on… 😉 . Even if not perfect: The manipulators work. Lot’s of other stuff in version 10 does not even exist yet.

  16. Hi Ben,

    I think you are wrong when saying that the mouse wheel is bad UI design. The mouse wheel is used in many applications for different tasks. Of course it is often used for scrolling like in a web browser – but for what else should it be used there. When using Google Earth for instance it is used for zooming – makes sense here because there’s nothing else to do with the mouse wheel (scrolling vertically would lack the option to scroll horizontally intuitively) and because zooming is a thing you always will do using the program.

    But what about X-Plane?
    When I’m using X-Plane I most likely set the zoom factor once I’ve loaded the plane. After that I only turn the virtual head around by joystick buttons (e.g. coolie hat). When I get my hands off the joystick/throttle it is to manipulate knobs. I never use the mouse wheel for zooming – that’s fact.
    But if there was the possibility to control knobs with the mouse wheel it would be much easier to set specific values. I know that because I was using MS Flight Simulator X for a while and it is really easy and a joy to do. You can turn the mouse wheel very precisely and you can also turn it fast – just like a real knob.

    Please think about the mouse wheel again. And honestly: Nobody needs the mouse wheel for zooming – all other view controls are on the keyboard – you can just make the +/- keys zooming – or something else…

    Best regards,


  17. I agree having the mouse wheel change knobs if it’s also used as zoom/view is a bad idea UI wise. Would it be possible though to give users the option (ie one or the other), or allow mapping of sliders to knob-twiddling duties?

    The reason I ask is that the x52 pro throttle has a nub that acts as the mouse and is good enough for getting the cursor over a knob but difficult to use to manipulate the knob (not precise enough for that, and it’s very difficult to click a button and use it). Being able to use the inbuilt mouse wheel or one of the rotaries or slider would mean not having to take hands of the stick/throttle. I can only speak for the x52 but I’m sure other Hotas sticks have similar functionality.

  18. Knobs are hard to operate in any 3D cockpit IMHO, this does not apply only to the 747.

    It is even harder when you use TrackIR and the view is jittering from the head *and* a simulated bumpy ride… It is hard to change heading, altitude and so on. I have worked around this by using keyboard commands but it is hard to memorize them all.

    I would prefer that when I click a wheel knob (or some other data input other than on/off) and hold the click input mode gets *modal*. Everything I do with the mouse while the knob is clicked regards that particular knob exclusively. This way you would not accidentally click anything else when the ride is bumpy and the head is jittering.

    I would love to have that.

  19. I think you should use the mouse wheel to turn knobs, too. It is much more intuitive than dragging considering that the mouse wheel is a real physical “knob”. I would expect that fine tuning AND fast tuning with it would be much easier, because we have learned to use it for a long time. 🙂

    Another problem with turning knobs is the use with TrackIR. Smallest movements of the head and/or certain flight actions like turns and accelerations (not to speak of turbulences) make me UNfocus the knob while dragging leading to “lose” the knob or even going from turning right to turning left inadvertently. I use to pause TrackIR when i am setting knobs now, but this isn’t a real solution.

    Maybe I prefer the option with holding down a button while turning the knob with the mouse wheel. Anatomically, I would use the left mouse button. I would have to get used to it a little bit, but still better than using the right button, which feels much more awkward. 😉 This way, I would not lose focus on the knob.

  20. Well, I see the reason against mousewheel beeing used as instrument/knob manipulator. Maybe I change my mind when dragging “per pixel” is avaiable but based on the sheer workload that I have turning knobs compared to zooming I would prefer the solution chris suggested. Since I use pilotview in order to acces “hidden” panel areas I almost never use the zoom function. And small displays should have pop-ups like JRollon’s CRJ has…
    But other users probably use the zoom frequently…so and after all I´m glad to hear that the mouse dragging will be more comfortable and intuitively.
    Good work!


  21. One more aspect which hast to be pointed out, why a mouse wheel (if you have one) would be ideal for turning knobs: The latching (right word???) of the mouse wheel giving feedback for every bit the knob is turned.

    Turning the knob by dragging consists of a lot of fine tuning while watching the whole time at the instrument, because you get no other feedback how many clicks you moved it. On the other hand, every click of the mouse wheel is a “click” for the knob. There is a reason, why knobs in real cockpits “click” (or latch) when turning.

  22. Hi,
    I absolutely agree with most people commenting here. The mouse wheel is by far the fastest, easiest and most natural tool to turn or manipulate knobs.
    I never was able to understand why X-Plane in version 10 still uses this clumsy, unprecise and for that reason slow way of dragging.
    Just think of those moments in a heavy iron on departure, huge workload, many things to do at the same time and having to fiddle around with this annoying knob dragging.
    Please guys – this would be a huge step forward to user friendlyness and acceptance of X-Plane.

    1. It’s anything but “natural” to Mac Users. Old mice, Magic Mouse, Magic trackpad: No wheel! basta 🙂

      1. Don’t you have the functionality where dragging two fingers up or down the trackpad acts as a scrollwheel?

  23. Because I very rarely use zoom and I very often have to turn the knobs, I would prefer the mouse scroll wheel for turning knobs and Alt + mouse scroll wheel for zooming.


    1. I agree completely. If I want to change the view angle, I’ll use the -+ keys, but I very very rarely do.

      I use the mouse to interact with cockpit elements, and never to interact with the camera.

      Ben, a possible solution: have X-Plane regard ‘scroll up’ and ‘scroll down’ as equivalent to a keypress or joystick button. Then the user can choose either to assign the scrollwheel to zoom, or to a new ‘increase/decrease element which the mouse pointer’s aiming at’ pair of commands.

      Then the user can choose: either use the scroll for zoom, or use the scroll for manipulators. It is transparent to alter these settings through the normal X-Plane input settings page.

  24. Ben, I think, the best solution to the problem is to make the behaviour of mouse wheel configurable. For example user can choose wether mouse wheel is used for zooming in virtual cockpit or for manipulating data. Also, as mentioned above, it would be good, if user could add a ‘key modificator’ i.e. ‘alt+wheel’ is used for zooming and ‘ctrl+wheel’ for manipulating data, and of course configurable.

  25. I agree with the majority of the opinion that has been expressed here. The mouse wheel to change data values in avionics stacks and autopilot interfaces etc. is a fantastic tool and just ‘feels’ right or at least similar to the ‘click’ of a rotary knob in an aircraft. With the manipultors on some third party aircraft, I’m sometimes not sure which way to push the mouse, do I go up and down or left to right? Some of the ways the manipultors have been designed by 3pd just don’t feel very intuitive to me. With the mouse wheel there is only one way to scroll, so it’s very easy to pick up. The only other way to change values that I have found very useful (and somebody has already mentioned it here) is the PMDG model with the left and right mouse buttons. If we want to convince more MSFS developers to produce for XP, lets at least give them something that they feel comfortable with utilising in 2d panels and the VC.

  26. I would also prefer to adjust knobs with the scroll wheel (or a two finger vertical swipe on Macs). Using a modifier key for either setting knobs or zooming (with modifier set for zooming) should be okay. Using a mouse button as the modifier is not good.

    But don’t forget to make knob adjusting modal, i. e. ensure that I after an adjustment, the focus is locked on the knob for a certain time, so that (under windy conditions) another knob just adjacent to it won’t be adjusted accidentally.

  27. Best altitude dial I’ve ever used is in my unreleased Lear. There is one drag to push/pull the knob in/out, which sets the coarseness of the dial to either 1,000 or 100 feet, then a left and right manipulator to turn the dial — so much faster to operate than the standard XP atrocity and there’s no over/undershoot. The trick is to limit dial rotation to once every 0.5 seconds, all done by plugin, of course. Probably broken too now that the “sim/time/sim_speed” is no longer outputting reliable data — when’s the fix or “sim/time/sim_actual_speed” dataref coming?

    Using drag for dialling altitude is silly. It’s better for setting things like OBS, heading or speed. But if you want to use the scroll wheel to do that, use the cursor as a trap. The scroll wheel should ‘manipulate’ a rotary only when the cursor is set to indicate left/right rotation, otherwise it defaults to zoom but with one important proviso: The scroll wheel should only reset to a new mode after a time gap of say 0.5 to 1.0 seconds, though it should disable the previous mode the moment the cursor changes.

    Cursor: Gone off rotary? Manipulator disabled immediately, zoom to be restored in 1-sec. Gone into rotary mode? Zoom disabled immediately, manipulator mode to kick in after 1-sec. Messy? Of course. If good GUI were easy everyone would have it.

    I’d rather the scroll wheel just kept to its single function: zoom. Javier’s problem is probably poor choice of manipulator-type and/or settings. Now that I’ve found my sweet spot, it doesn’t surprise me it’s about to get an “upgrade.”

  28. Regards TrackIR – I have exactly the same issue with jitters and maintaining focus on a knob. It’s not always practical to click and hold on some settings, particularly where you need to go through a few cycles of tuning/observing instruments and perform a series of discrete adjustments. It’s worse using TrackIR Z-axis zooming so I tend to disable that axis and use the scroll wheel.

    What I would find useful* is a method to toggle the focus on a manipulator in 3d view so once captured, no modifier key or button needs to be pressed and the scroll wheel can be used to change values. A mouse click could cage/uncage a manipulator and the scroll wheel perform the manipulation. The beauty of this is that you can still scan around with TrackIR even with the manipulator out of view. It’s a reasonable simulation of reality where a pilot does not need to maintain close focus on an instrument knob once they’ve taken hold of it and where observing the effect of its adjustment elsewhere in the cockpit is a priority.

    *The varied responses in this thread pretty well demonstrate the host of UX problems balancing intuitive vs conventional UI design and how personal the governing criteria can be.

    1. I must say I totally agree, this looks like the most intuitive and natural solution. Ben, please please give all of this a second thought!

  29. forget the mouse wheel idea and go with the left/right mouse click/hold to set alt, and climb rate

  30. I’d just like to add my vote against the drag-to-turn UI. I avoid flying the 747 for that reason. Much happier with the click-to-turn idea, especially where you can just hold the mouse down while the numbers spool up and you can focus on other things. With dragging your whole attention is directed to operating the mouse for what seems like an eternity.

  31. I have to add my voice to the pro-mouse-wheel-for-data-entry choir here. After all, of all the input devices an ordinary home computer has, the mouse wheel is the one most similar to a rotary knob. And the mouse wheel has always been used for data entry even in X-Plane until very recently: for the throttle.

    The zoom vs. manipulate problem can be solved elegantly by clicking (preferably with the scroll wheel/third button, if available) to cage/uncage a manipulator, as suggested by mattp. This would also solve the view jitter/turbulence/TrackIR problem, as well as open the feature to the trackpad/Magic Mouse users: (two or three finger) tap to cage/uncage, two-finger swipe to manipulate. Indeed, this is a reasonable simulation of what is really a three-part process in a (shaking) real cockpit as well: Find and grab the knob, once you’ve got hold of it, turn it, and when done with it, let go and retract your hand.


  32. I find, that the most irritating thing is, when
    I turn a knob to the left and then release, The view
    Jots to the far left window of the cockpit!!!

    1. Use command-look, not mouse-look. We may remove mouse-look mode as you can now look with command-look and still drag around with the right mouse button.

  33. I’m pro-mouse-wheel, all the way. Ben, what you’re describing in this post as “pixel drag axis…” correct me if I’m wrong, but isn’t it already available as an X-Y drag manipulator? The value entered there seems to be in pixels. Just leaving one axis out has generated the desired effect for me. I use it all the time, for the reasons already mentioned here. But, of course, I’d use scroll wheel implementation, if it was available.

      1. It’s not bad at all for a few things so long as you consider both axes to take into account the geometry of the 3D view, but using it to drive two datarefs according to axis isn’t a good idea.

        1. Vonhinx, if I understood your post correctly, I’d say I disagree with it. Maybe what you’re saying applies to throttle levers, and objects that are actually moving along with the manipulator movements in 3D space… but even there, I find it more intuitive to drag up – down or left – right in terms of screen geometry, as opposed to 3D space… ESPECIALLY since the drag axes change somewhat unpredictably (for instance, you drag the throttle forward, and then you want to drag it back, but because of the new orientation, the drag axis is almost reversed). These are severe UI problems that are solved with 2D drag. Normally, once you’ve started clicking and dragging, the most intuitive directions are along the 2D planar axis of the monitor as well, regardless of the viewing angle.

          I’ve implemented an XY slider system on the upcoming Carenado Seneca for the throttles, mix, and prop levers, where dragging vertically pushes the levers up or down in sync with each other, and dragging horizontally creates a differential movement between the two levers. Very intuitive, and it works from all viewing angles. Using an XY drag manipulator to drive two datarefs according to axis is a very good idea. It works way better for my 2-axis sun visors as well. Before, these would invert drag direction as well, when the orientation was changed. The XY drag manipulator fixes all of this.

          1. Yup, it works fine for your sunvisors. But when I look right, are the axes vertical and horizontal with respect to the plane of my screen or to the plane of the panel? In a 2D world, it’s always the screen; in a 3D world it’s not that obvious. If you take the screen view in the latter, you force the mind to reject the 3D view. If you take the latter view, a drag right while looking right has a vertical component.

          2. Maybe that should be:

            If you consider the 2D drag in terms of the plane of your screen whilst looking left or right of center in a 3D cockpit, you force the mind to reject the 3D perspective. If you consider the 2D drag in terms of the virtual plane of the panel, a drag along any axis involves some drag along the other axis.

  34. C’mon Ben, give in; Or do I have to call my 7 sibs to comment pro mouse-wheel too?

  35. I don’t have time to read all those, so I leave it for those that HAVE to read them (the devs that want our feedback) and just give my feedback.

    Positioning mouse over a knob, CURSOR CHANGING SHAPE (this is vital) and mouse wheel adjusting the values is VERY intuitive and easy and many programs use it (music studio software comes to mind) – I wonder how you didn’t find them.

    I don’t really care for zoom. It should be there somewhere (possibly with modifier key) but nothing too important, simply because “zooming” makes no sense in real world. You don’t wear binoculars in a real plane.
    Someone could argue that “zooming” for the instruments (and only for the instruments) is like “bending towards” a set. On the other hand I can argue that (1) if you can’t read instruments clearly (because of your own limitations), you shouldn’t fly a plane, (2) modern high resolution 20+ inch monitors are like the stock option nowadays. No excuse. (btw this gets me back to the older post about making a program that collects real anonymous user hardware statistics)

    My 0.5.

    1. >(1) if you can’t read instruments clearly (because of your own limitations), you shouldn’t fly a plane

      Who’s flying a plane? We’re ‘flying’ a screen of 72 or 96 dpi.

  36. First time poster, but long time reader.
    For what is worth, count me in on the mouse-wheel-for-turning-knobs crowd.

  37. Ben, please rethink this. Mousewheel to input knobs it totally natural – in real life you turn the knob, in the sim you turn the mouse wheel while pointed at the knob. Current system is, truthfully, poor.

    Use + and – for zoom if you have to. Realistically, how many people actually change zoom while flying? (Other than, I suspect, to zoom in on a knob because it’s so hard to turn it….)


  38. Hello guys, Hello Ben,

    I have nothing to add to otehr’s comments. As a dev and as a user, I would be more than happy if I can manipulate every command and knob with mouse wheel.
    Manipulator are great, but not very intuitive or natural to me.
    Some dev put up/down move, some left/right, etc…Lets get a standard with mouse wheel input, and a zoom behavior while pressing CTRL, like in ALL modern apps.


    1. Whether we get it or not, be careful of what you wish for. It’s not a cure-all. Prepare to get a sore finger scrolling the wheel to select altitude depending on the settings of the scroll-wheel-manipulator made by the dev. GIGO applies: a poor choice or implementation of any control method will still result in a poor user experience.

  39. Laminar Research please listen to your users!

    Mouse wheel for manipulating knobs works great in FSX with PMDG products, its intuitive!

    Please give user option to use something else for zoom and thus mouse wheel for knob manipulation.

  40. Hello.

    I would have liked to change values with the mouse wheel. Why not implementing the feature and let the user decide to activate it or not?
    The CAD System SolidEdge has this feature. You can change values (dimensions) with the mouse wheel. So much for “bad UI design”.

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