Unity 5 Wheel Colliders going off-road

[TiktaalikDreaming]

I never messed with wheels in pre 1.1 KSP, so I don't know if this is new or always existed.  If it always existed, no-one seems to discuss it.  So, onwards...

I've noticed that rovers (esp 4 wheel rovers) get stuck with no motive power when their wheels are the only parts touching the ground, but it's not the "bottom" of the wheel.  Eg;

While this might be a fine approximation for a track race car, it seems somewhat limiting for an off-road vehicle like a lunar rover, or any rover for that matter.

I notice in Unity, once you add the Rigid Body so you can see the wheel collider, that there's a small ball of lines drawn in at the bottom of the wheelCollider.  This seems to correspond to the part of the wheel that can drive.  See;

There doesn't seem to be any configurable value to change this widget.  Does anyone know what it is?  Or why only a tiny bit of the wheel is capable of producing forward force?

Thanks

[TiktaalikDreaming]

Unexplained widget appears to be the "Force App Point Distance".  From what I can find out, it is the point at which the wheel's forces apply to the rest of the vehicle.  But, changing it doesn't effect the "wheels only drive when surface contact is directly in line with suspension" issue.

Judging from discussion going on in the Kerbal Foundries wheels posts, I'm inclined to think this is a limitation imposed by physx and it's gross oversimplification of wheels. 

[nli2work]

I don't think that bit is implemented in KSP wheel modules, at least not far as I can tell from looking in the modules... I been thinking of using wheelBogey module as a poor man's way to orient the wheelCollider to the ground. haven't gotten around to trying it though.

 

Edited May 7, 2016 by nli2work

[TiktaalikDreaming]

2 minutes ago, nli2work said:

I don't think that bit is implemented in KSP wheel modules, at least not far as I can tell from looking in the modules... I been thinking of using wheelBogey module as a poor man's way to orient the wheelCollider to the ground. haven't gotten around to trying it though.

 

Yep, looks like.  It makes going off-road (aka, all of KSP rovering) a bit tricky.  <Nerd-rage>  Oh well.