Yeah roof flaps are not too hard once you grasp the process, its just models of the roof flaps in an open and closed state. Then with BBOX region for the roof flaps whne they need to deploy the game knows the models in that region that are named in the script will react. In the script you'll see the flaps are controlled by the morph states of them open/closed essentially. In new gen cars it can be a bit more complicated if you have roof flaps on the hood wit open spots like the gen6/gen7/ICR mods but not many mods use the more complicated process.
As for LODs they are not hard but very boring/tedious having to do 3-5 different levels for each car model. It starts to become a logistics game making sure you get all the models named correctly and coded into the script without error. Its why naming conventions are extremely helpful. If all the models across all LOD states are named the same thing except having like L1, L3, L5, L7 L9, L11 for the lod levels then it becomes much quicker copy/replace in your script, notepad++ makes it easy for me to do that.
Now the damage + LODs version of a mod is where it get more complicated, you have to have damage but also LODs for every level of damaged part too. When a car take damage its not technically the same mod anymore, it switches over to a completely different set of models so they can take damage/take more damage if you crash more.
As for LODs they are not hard but very boring/tedious having to do 3-5 different levels for each car model. It starts to become a logistics game making sure you get all the models named correctly and coded into the script without error. Its why naming conventions are extremely helpful. If all the models across all LOD states are named the same thing except having like L1, L3, L5, L7 L9, L11 for the lod levels then it becomes much quicker copy/replace in your script, notepad++ makes it easy for me to do that.
Now the damage + LODs version of a mod is where it get more complicated, you have to have damage but also LODs for every level of damaged part too. When a car take damage its not technically the same mod anymore, it switches over to a completely different set of models so they can take damage/take more damage if you crash more.