Converting a track (Adria) I did in 2007 for GTR2, instead of going in 3DSimed I made the conversion in 3dsmax2017, done all the requested parameters with names as TDF file and named all objects relevant like racesurface#. It seemed all good and tried the track 3 days ago and it was fine, did a start AIW that would be rechecked later, so I go in final details in Max. Yesterday I went again in track and surprise (really a surprise after done more than 100 tracks over the years) there are no grip in certain places and the car slips on it with no grip at all going straight until getting an outside surface like grass or kerb or concrete strip. So the same material in the track just turn the grip on/off in some places, I tried all I could remember even get a collision mesh for road named road_collision but just the same the grip turns off/on in the same places. When I change to AI it makes the track with no grip problems at all. This is in the minimum weird, since it worked before like it should for theme the user and suddenly "bump". I tried to make an installation in the game but it's the same for user while AI is working fine. If someone knows what that can be how to solve it would be much appreciated, I was thinking in getting the track for everyone download. Thanks.
Problem solved the skidmarks were making the surface with no grip, the curious thing is that was not all the sections only part of it. It accepted the no collision surface material name "skidmarks" and even with no collide and Hat got it very slippery not sure how.
Just make the skid marks non collideable,non hat, and a decal, otherwise, when you drive over them, you'll feel a bump, and you don't want that.
They were no collidable, no hat, and checked decal, there was no bump on it, they just made the car slip without control until leaving the skidmarks surface. The problem was solved changing the name of the material. Maybe something rFactor 2 stuff should advised the modders to not use it, maybe it was only me , thanks for your reply.