Elevation/Altitude

Discussion in 'Track Modding' started by PLAYLIFE, May 30, 2012.

  1. PLAYLIFE

    PLAYLIFE Member

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    Apologies in advance, my track modding knowledge is essentially zero.

    Currently, do the tracks files allow a defined global track elevation (in terms of 'altitude' above sea-level)?

    This is important because air density changes with elevation which should effect both aerodynamics and engine physics heavily. Air temperature is covered (although not sure if it interacts with the physics) but elevation/air density perhaps is not? Obviously at higher elevation the air is thinner and you get very different car performance in both these aspects.

    Air density at sea level is 1.225kg/m^3 while at 2,500m it is significantly smaller at ~0.95kg/m^3.

    For instance, the Autodromo Hermanos Rodríguez sits at an elevation of around 2,400 metres and F1 teams used to experience some 20-25% less engine power and aero (amount varies depends what you hear and read).

    Similarly, Autodromo José Carlos Pace (Interlagos) sits at 800m elevation and although not quite as severe as what Mexico used to be, still has a measurable effect. Interlagos scheduled at the end of the season has been a blessing in the past few years with the 8 engine ruling as it's not that hungry in terms of engine wear.
     
  2. Luc Van Camp

    Luc Van Camp Track Team Staff Member

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    This is what I found in one of the Mills GDB files:
    Code:
      Latitude = 37.41    // degs from Equator (range: -90 to 90, positive is Northern Hemisphere)
      Longitude = -78.60  // degs from GMT (-180 to 180, positive is East)
      Altitude = 182.0    // meters above sea level
    Right now there is no difference yet between running at sea leavel or at 2000m though.
     
  3. Jka

    Jka Member Staff Member

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    As a car point of view, but is it affecting overall lightning (track coords and altitude) because angle of sun is differs on different altitudes?

    I thought I've noticed little bit different shadow casting on different altitudes. It must have been my imagination then... :D

    Cheers!
     
    Last edited by a moderator: May 30, 2012
  4. Luc Van Camp

    Luc Van Camp Track Team Staff Member

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    For once I was talking from a car point of view :) . Lighting and shadows are certainly affected by these values, yes.
     
  5. woochoo

    woochoo Registered

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    Hi guys,
    I've been waiting for this thread :)
    My version of Longford is built with 0 meters as sea level, and the track ranges between 35-160 meters above, as in reality.
    Would it be better moving it all down 160 meters to 0-level and having the gdb height offset, or leaving it as-is with real world altitude?

    I can get around the blank AIW starting issue, but sun/shadows and car performance differences (when implemented) might be different.
    Will 160m be treated as 160m or 0m if there is no height offset, or does each meter make a difference relative to world origin?
     
  6. Luc Van Camp

    Luc Van Camp Track Team Staff Member

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    It should make no difference, unless you offset your scene in Max by astronomical values. Using the GDB offset is the easiest solution. Plus it probably saves a few ... bytes ... when you do the CAM and AIW files because the set of coordinates will contain slightly smaller numbers :) .
     
  7. woochoo

    woochoo Registered

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    Haha, well I'll keep that in mind
    Thanks Luc
     
  8. PLAYLIFE

    PLAYLIFE Member

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    Thanks for that Luc. Even if not implemented yet it's good news that it has been thought about and there's an area where that elevation/altitude can be defined :cool:
     
  9. jubuttib

    jubuttib Registered

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    Oh goodie, now I'm imagining a proper Pikes Peak, raising 1,400 meters from start to finish, with the air getting thinner and engines losing power towards the top... =)

    EDIT: Especially interested if it'll be done properly, with NA engines losing more power than turbo engines.
     
  10. Fabio Pittol

    Fabio Pittol Registered

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    Luc, am I doing something wrong or the Dev Mod doesn't load these values, except the Latitude?

    It's pretty anoying to ajust it again everytime I load the track.
     
  11. Luc Van Camp

    Luc Van Camp Track Team Staff Member

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    Just loaded a few tracks in the Viewer, and I'm getting 0 Altitude, Latitude and Longitude. It used to work before :) .
    So you're probably doing everything right ...
     
  12. Fabio Pittol

    Fabio Pittol Registered

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    At some moment I loaded the track and it randomly loaded and "saved" that data. Now always opens with everything set right.

    Maybe it's some cache-related issue.
     
  13. Tuttle

    Tuttle Technical Art Director - Env Lead Staff Member

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    The devmode (as the singleplayer) needs a complete game quit to load the new .GDB file whereas the viewer never worked for me with location data.
     
  14. Fabio Pittol

    Fabio Pittol Registered

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    Note taken. ;)
     

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