I have been working on porting the bobcat from GTA SA to BeamNG and I can't get the jbeam to work properly, I think it is the cross beam bracing causing everything to go wrong because when I use my own model made of rectangles for the jbeam it almost works, but the model from GTA sa uses triangular polys so I dont know how to add cross beam bracing to it, from the wiki they just look like x's but i cant make x's out of a triangle. Can it be done a different way? Or do I have to make my own model for the jbeam? I do not mean to sound dumb but I have not used blender much.
For the visible 3d model, that should be fine. For the jbeam, it will not be fine. You will need to either make the jbeam yourself, or significantly edit the output from exporting that. I would recommend either doing the jbeam from scratch, or, if you don't fancy that, you could start porting it onto the d series jbeam.
Think it this way, nodes will fall to ground by themselves, but you add beams to hold nodes on place. So for each node you need to think about which direction it needs to have support to stay on place. Then you can start thinking about how those beams transfer impact energy and different stresses put to nodes. For example if node in front left corner is lifted up, what kind of beam structure will keep shape as a car with appropriate amount of flex, that is difficult part and requires lot of tuning to get right. So, nodes are what is your car, beams just hold them where you want nodes to be, from that it becomes easier to figure out where to add your beams. Also check out official cars in game, enable beam and coltris debugs and see how cars are made.
