W.I.P. Vancouver City Circuit 95 Layout Lidar version

Discussion in 'Tracks' started by JrC, Dec 30, 2021.

  1. Johnr777

    Johnr777 Moderator

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    Yeah, the Lilski video tutorials show how it’s done in blender.

    Car data for any particular track is extremely rare, usually some of us are lucky to have an in with a race team or 2.

    Someone posted something in the Trois Rivières track about extracting data from onboard camera video. But he wasn’t very forthcoming with information.
     
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  2. JoeK

    JoeK New Member

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    Extracting data from video is a tricky thing. You have to break the video down to individual frames, and then use the specialized software that builds a surface from the multiple frames. You have to give the software location of each frame (coordinates) so it can compute the parallax and the depth of field to common objects within the frame.
    This video gives a good illustration how the process works:


    Unfortunately I don't think a video has enough quality resolution to get decent results. Might be worth testing.

    Edit: The coordinates must come from the cars' onboard GPS system and the video camera must be high rez & fast shutter for it to work, I'd speculate.
     
    Last edited: Jan 11, 2022 at 6:19 PM
  3. Johnr777

    Johnr777 Moderator

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    The data im talking about is vertical camera movement, to capture bumps
     
  4. JoeK

    JoeK New Member

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    Ahhh... onboard LiDAR unit that interfaces with the GPS to create a coordinated elevation data.
    Probably a narrow angle specialized version of a mobile scanner like this:


    I've worked with this data before. One can pick up pavement cracks with it and how deep they are, as well as all the bumps and rutting of the asphalt.
     
  5. Portland12345

    Portland12345 Member

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    If you had actual real world telemetry you could build bumps off suspension movement.

    Chances that you can find Vancouver 95 telemetry out there somewhere not high probably.

    I agree with john other than studying onboard footage or checking photos there is very little chance you will get actual bump data.
     
  6. JrC

    JrC Active Member

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    yeah... back then we weren't even as computerized so its unlikely. Im fine with studying the onboard video to build it to the best spec possible...

    Appreciate the discussion guys. This one is more about doing the best with what I can get so I will work up rather then down.
     
  7. Mitch9

    Mitch9 New Member

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    Yeah you have enough in your plate already and you really need to get the basics down, no need to overcomplicate things right now.
     
  8. JrC

    JrC Active Member

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    Im pretty sure we can get there... im nothing if not annoyingly relentless...

    And i have a portion of the AC stuff already. That was the hope behind the conversion because this was always going to follow that for me at least. How long it takes is another story but i would like to build a realistic version based on what can be gathered even if not 100% perfect due to the obvios limitations.

    It just means i have to watch a lot of race footage and build up some type of system to understand and document what im seeing.
     
    Last edited: Jan 12, 2022 at 6:46 AM
  9. JoeK

    JoeK New Member

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    Since you (JrC) live in Vancouver/LM, you can walk the local streets the race was held on. They've since been re-surfaced, but the city had to grind the old pavement off (12 to 20yr re-paving cycle) and lay new asphalt to match the existing concrete curbs and manhole rims - so the course streets are pretty much on the same elevations. I remember the initial discussions on the concerns about the safety of the race course and a lot of concern stemmed about the traffic rutting in the road lanes and the crossfall across the intersections.

    There was some concern the race cars might get air under the chassis from the intersection crowns and tires might wander in the rutting. I believe the city re-paved the course streets prior to the races, but let the asphalt weather for a few months to get rid of any residual oil from the paving so the asphalt wouldn't be greasy. The re-paving would include a road crown (for drainage purposes - to get the rain water off the surface) where the centerline (and paintline) of the road would be.

    Another concern was that at regular speeds, the the road irregularities are not noticeable but at race speeds the road crowns, rutting and typical paving undulations will make the course very bumpy as the race car transitions across the width of the road from one edge to the other.

    If you do a walk-through, you can have a look down near the pavement level and see the ridges and undulations that occur. Photos at sunset/sunrise help ID those spots with shadows but it can be tricky. Taking pix right after a rain storm can help ID the low spots. Same with driving it late at night or very early in the AM at speed and feeling how the car suspension reacts at certain points in the road. These notes can help in designing the same undulations into your AC road course. I admit, this is a difficult task to accomplish as there are so many variables to re-create and mimic.
     
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  10. JrC

    JrC Active Member

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    @JoeK

    Used to live...

    I escaped to rural Alberta ;)
     
  11. JoeK

    JoeK New Member

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    Oooops!!... :eek:
    :)
     
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