Tutorial: how to fix steering wheel axis

Discussion in 'Car Modding' started by Mauro, Jan 9, 2020.

  1. Mauro

    Mauro Registered

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    importing an old car into RF2 with 3dsimed the steering wheel axis is often not perfect
    after losing many hours trying to solve it, I found a quick and easy solution
    maybe it could be useful for some other

    P.S. if you need in future to edit steering wheel you need to open it "import as a model"

    How to fix steering wheel axis

    -import all the car as an object
    -select steering wheel object, in this case "swheela.gmt"
    (if you have many steering wheels check .gen for find the correct .gmt)
    -press 1 "calculate pivot center/pivot set to geometric center"
    -you can check it with 2 Rotation/roll values -ex. insert 45 than reinsert 0-
    -press 3 "isolate object"
    -export it overwriting

    [​IMG]
     
    Last edited: Jan 9, 2020
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  2. Rastas

    Rastas Registered

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    And then there is the sin and cos angles in cockpit.ini :)
     
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  3. Mauro

    Mauro Registered

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    yes
    but some old mods, like f1 1971 (and 1975 -i think-), don't have that string in cockpit.ini
     
  4. Coutie

    Coutie Moderator Staff Member

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    You can add it, it won't break anything, and you don't need to mess with the models.
     
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  5. JorgeAH

    JorgeAH Registered

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    how could i fix in3dmax if the steering wheel is outside the cockpit when i turn right or left?
    thanks
     
  6. Coutie

    Coutie Moderator Staff Member

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    Might be the axis in the cockpitinfo file, and not max. Or it could be the pivot point in max.
     
  7. JorgeAH

    JorgeAH Registered

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    what line in the cockpitinfor? i dont find.
    In max, i tried a lot of options, 0,0,0, Center model, center pivot, Xreset, nothing works
     
  8. Bernd

    Bernd Registered

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    In the exporter rollout, check "move", if the pivot point is set properly to its center, it will stay inside of the car then. :)
     
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  9. Brent

    Brent Registered

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    How do you establish the steering axis vector? When I set the pivot point following these steps here and try to change the rotational values, the wheel rotates around those axis but none rotate about the axis of the steering shaft. Is there a way to change the normal vector in 3dsimED? And once you do that which vector axis establishes the steering wheel axis, should it always be say Z and the direction it's pointing be important?
     
    Last edited: Jan 24, 2020
  10. JorgeAH

    JorgeAH Registered

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    how could i check this?
     
  11. Lazza

    Lazza Registered

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  12. Brent

    Brent Registered

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    @Lazza Thanks! This is what I was looking for. A couple quick things on this.

    Do I assume the 0.0 value is some kind of offset for the wheel that's rarely used?

    Would the steering wheel axis angle for the sine and cosine values be ϴ here, angle measured from the ground? Edit 1/29/20 Answered by Bernd in the thread Lazza linked above - The angle you use for sine and cosine is the angle from the vertical to the steering axis. In this diagram (90 - ϴ).

    I know I can try to experiment with this using the angle relative to vertical but I'm hoping to settle this. It is settled!
    [​IMG]
     
    Last edited: Jan 29, 2020
  13. Lazza

    Lazza Registered

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    @Brent I'm no expert, I just read a lot and search for answers :)

    That other thread mentions an angle of 20° from vertical, so 90 minus your theta there. A quick test should confirm. (but it would agree with the example figures, too)

    The x component being zero makes sense; if you rotated purely around the x axis (which is left to right in front of you), the wheel would rotate forwards and backwards. I can't see any reason you'd want a steering wheel to rotate at all in that fashion :D

    (just to help with that mental imagery: a rotation axis is like a skewer through the object, so the object rotates around that axis. The x axis runs from left to right, parallel with the front edge of a desk you're sitting at, so if you rotated the wheel around x it would tumble forwards and backwards. In this game the z axis is what points in front of you (actually behind you, but in this context the direction doesn't matter) so usually that will have the largest rotation component [and therefore value] since wheels generally are close to vertical. A bus steering wheel would likely have a greater y component (pointing up) as they're closer to horizontal)
     
    Last edited: Jan 24, 2020
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  14. JorgeAH

    JorgeAH Registered

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    finally i wrotte (0.0, sin,cosin) and its works, wheel is 90º with horizon plane and turn well

    thaks
     
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  15. Lazza

    Lazza Registered

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    @JorgeAH you're welcome, but did you have to reply to the other 2 year old thread? I only linked to it for reference.
     
  16. JorgeAH

    JorgeAH Registered

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    sorry, i didnt see the date of the post
     
  17. Lazza

    Lazza Registered

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    @JorgeAH well, as above, the 20° would be between vertical and the wheel. So sin() and cos() of 20° will give the desired angle.

    Of course you could instead take the angle between the face of the wheel and the horizon, and use cos() and sin(), since sin(theta) = cos(90-theta). Take a few moments to understand the maths, and try a test or two, and it will all be clear.
     

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