QUESTION Help with model component mates and orientation

[bikerbob951]

Hello again friends,

I'm attempting to port a car that I've designed in Solidworks. The issue I'm having is the front suspension components showing up in 3DsimED and KSEditor with incorrect orientation, as if they were never mated in the parent file, although they definitely were. "Fixing" the components in the SW model seems to help, but it makes the SW file tree VERY unhappy (see first pic).

My questions are:

1. How do the suspension components know where to fix in the .fbx and .kn5 models? Do I mate them in blender or something?

2. Does the precise location of the car's origin matter as it relates to game data? For example, the CoG of my model is not exactly between the front and rear wheels, but it looks like a lot of kunos cars are set up so the origin is equidistant between the front and rear axles.

For the curious, my workflow is as follows:
- Model exported from Solidworks as .STEP (AP214) file. All susp. still looks correct.
- Model imported into CAD Exchanger and exported as an .fbx file. All susp. still looks correct.
- Model imported into 3DsimED 3.2c Some susp. components lose their constraints.
- Model exported into KSEditor as .kn5
- FWIW, I haven't edited the suspension.ini files yet, they still reflect the stock Kunos formula example

I hope I was clear with my questions! I included a few screenshots for reference.

 

[Fuzo]

Go to the Assetto Corsa/SDK directory and find Modding Pipeline PDF file there, read it and you should find answers for most of your questions.

But in general, AC engine is using null nodes/helper objects with specific names and hierarchy and orientation. It will find specific node by its name in the FBX file and move it or rotate it according to car data ingame. So you need to follow the hierarchy and naming convention. And you need to set some basic data like wheel base, front and rear track and weight distribution in the suspension.ini. If the body does not fit and moves somewhere where it should not be, you can adjust its position visually in the beginning of car.ini file. (graphic offset). But just the body (or basically everything else which is outside suspension nodes).

Some nodes like wheel nodes need to have specific orientation, Y axis heading up, Z axis heading to the front (local mode). Other nodes can be adjusted for your needs. If you have something like arms which are the same on both sides and you want to make them work in an animation, their origin needs to be adjusted as well. If something is flipped ingame, you need to fix the origin of the object (or parrent null). Check the pipeline, it is quite well explained there. There are even some examples in SDK directory, you can reverse engineer it.