[mhh__]

Unreal docs are fairly good for making games but if you want to modify the structure of the engine it's quite annoying/nonexistent.

Case in point: Vehicle physics is no where near as good as the docs imply (not a toy but still 20 year old vintage), but there is almost no documentation of how PhysX interacts with the Unreal engine proper i.e. you can get the PxRigidWhatever handle but you can't easily replace PhysX with a proper MB package. Epic seem to be transitioning to Chaos but it's not documented yet.

If I ever get good Vehicle physics working I'll write it up (it's definitely possible but I'm not sure how ACC does it)

[djmips]

People customizing the UE4 engine professionally or on large projects put a lot of work into the areas they are interested to the point where it's not really UE4 anymore in that area. Gears of War is a good example where areas of the rendering system would be almost unrecognizable as they have put in countless man years of work diverging from the base engine.

[mhh__]

I'm sure it's possible I'd just rather not read thousands of lines of code to find the nitty gritty.

I want to make the basics of an open source (sim)racing game (as a test bed for writing tyre models), without using the fairly lacklustre offerings included by default (e.g. no sprung mass, no carcass stiffness etc., idealized suspension etc.). I have no need to go into the bowels of the rendering engine but it struck me that the interactions between PhysX and the actual actor model for the vehicle is almost not documented at all. I assume it's possible to do it solely with PhysX (proper suspension) but I cannot find any case studies of people doing it with the possible exception of their drive project which is under $$$ and NDA I'm guessing.

I was also slightly surprised that I had to go looking for the option to connect to the PhysX debugger. It wasn't hard to find but I was half expecting it to be included with the engine.