Author Topic: Question concerning curves with elevation  (Read 662 times)

MarcellusW

  • Posts: 105
In my attempt to recreate Flatout2's City1 track(s) I have a problem getting the mesh geometry on curves with elevaton right. ( either going up or down )
What happens ingame the moment a car comes to an elevated curve going up or down is:
 the car totally looses grip on the surface untill it hits a guardrail, a wall or comes to a full stop. ( it's like the car suddenly goes from tarmac surface to an icy surface )
I have tried several ways to deal with the situaton, made different mesh ( low and high polycount, triangulated quads to match curve direction and opposite ) to no avail.
I think this might have to do something with the road angle perpendicular to the drive direction, although I have tried to compensate for that aswell.

Could someone please tell me how the geometry of an elevated curve should look like?

Thanks in advance.

MarcellusW

The Very End

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  • Posts: 2417
Hey! Fear not, you are not alone. What helped for me was to use the script "quadrify all": http://www.scriptspot.com/3ds-max/scripts/quadrifyall . If that does not work please just write here again.

Usage: Select the model, run the script IIRC.

MarcellusW

  • Posts: 105
Thanks for the reply.

Forgot to mention that I'm making my initial mesh in Blender. ( because I have the original FO2 tracks in Blender aswell )
I only use Max to add objects of sorts and to finalize textures.
My initial mesh is all quads, I experimented with tris to see if that would solve the problem and on some parts it does, but not all.



The Very End

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Yeah, but there still are some strange things happening, even if the mesh is fine and everything. Don't know what it exactly does to help, but the quadrify all seems to fix most issues for me. If you test it now, does it make any difference?

MarcellusW

  • Posts: 105
I would need to port it to Max first before I could test, wich will take time for me, I was kinda hoping for a workaround before I port to Max.

The Very End

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Hmm, do Blender have anything like xform reset?

MarcellusW

  • Posts: 105
since the lingo used in all different 3d apps is not the same it's hard to get this question answerd, so, not sure if Blender has a feature like that. ( just googled for this )

Thing is, I had similar problems on another track ( though not as severe as on the City1 track ), I was able to fix the other track by leveling the vertices on the left and right  side of the road segments.
Now the road segments on the other track are squared quads, while the road segments of the City1 track are rectangular quads.
It's giving me a bad headache.

I will leave it for now and focus on the FO2 Speedbowl track.

The Very End

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If it is to any help I can throw the quick fix on the model and see if it works. If you send the road model to me in ibj / fbx / max or other format that should be workable.

sam223

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Hmm, do Blender have anything like xform reset?
Ctrl+A in blender is similar to xform reset in max
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MarcellusW

  • Posts: 105
Thanks Guys, that partially did the trick, the first curve going downward went well, no problems other that speed related issues.( especially in the shortcut in the park )
2nd curve going upward is better but still has 2 spots were the cars spin out of control no matter the speed and 1 spot that feels like glue. ( I guess bad geometry )
The strait end leading to the 3rd curve upward seems all but slightly tilted down the outside corner causing the icy effect, but as soon as the car is in the curve it has grip again and than comes to another spot feeling like glue. ( also bad geometry I guess )
4th and last curve going upward ( I have only adressed the curves with elevation since the curves on leveled ground cause no issues ), drifting in the start of the curve might just be speed related, but halfway to 3/4 up the curve a glue spot again and what seems to be an irregularity in the road mesh.

Indeed a good step in the direction of fixing this.

Thanks End, Sam for bringing some light back in my modding darkness.   :)

MarcellusW

  • Posts: 105
It's bad geometry for sure, the elevated curves need to be sloped gradually, there are some spots in the curves that are flattening out before sloping up again causing bumps and dips.
I think I can fix that.

Purple44

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Hi MarcellusW, hey have you checked the AI race line with the in-game race line tool? There no weird jogs in race line effecting the AI?

Flatout Joint, where the mods were.

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MarcellusW

  • Posts: 105
The AI racing line seems ok, it's bad geometry for sure.
I can't make video to show what happens and my English isn't good enough to fully explain the issue(s).
I think it has to do with the way I have made the road mesh for this track, on another track I'm working on all roads are squared segments,
the road segments on City1 are rectangular perpendicular to the driving direction, I have a feeling the game doesn't like that.
Currently testing this feeling.