PC2 Rain, Drying, Wet Weather Physics / Driving Implementation (PC1 & PC2)

[Spinelli]

Can anyone tell me how the rain works in Project Cars 1 and 2 (and Automobilista 2 if you'd like as they all use an iteration of the Project Cars engine)?

Is it physics based? In what ways? In what ways is it not physics based?

Is every part of the track equally wet?

Are there puddles?

Are the puddles and more wet looking areas compared to other less wet (but still wet) looking areas just graphical or physics-based too?

If there are puddles, are the locations and size of puddles scripted or is it based in real-time according to the 3D geometry modelling of the track?

Does the track dry according to where cars drive over?

Can we trust what we see graphically - wether a part of the track looks more wet, more dry, a deeper puddle, a less deep puddle - to be reflected in the physics or is a lot of it just graphical, or are some aspects of it physics but some are only graphical?

If there are drying lines generated from other cars, is the drying line 100% based on where cars drive over or is there also a scripted drying line that also occurs?

Is there any benefit in some types of corners / cars / tyres / track conditions to ever experiment with driving off-line (when driving offline can sometimes offer better grip in the wet, also known as the "karting line")?

Can some types of kerbs and painted surfaces be extra slippery relative to other parts of the track when it's wet?

Please share any technical aspects of the wet weather physics driving model that drivers/players should know.

 

[Emery]

If there are puddles, are the locations and size of puddles scripted or is it based in real-time according to the 3D geometry modelling of the track?

Does the track dry according to where cars drive over?

Can we trust what we see graphically - wether a part of the track looks more wet, more dry, a deeper puddle, a less deep puddle - to be reflected in the physics or is a lot of it just graphical, or are some aspects of it physics but some are only graphical?

Yes there are puddles and they're defined in 3D such that puddles have different depths (but I recall it being a separate 3D mesh from the track mesh). Like real puddles, you can't much tell the depth other than how far the puddle spreads. Deeper puddles do affect the handling more strongly than a shallow puddle. Speed through a puddle and available tread determine how much hydroplaning happens. The track dries where the cars drive, provided the rain has stopped.

IMHO, pCARS hydroplaning was overdone with treaded street tires as 60 mph through a puddle was stupid wicked because we know in real life people do that all the time.

 

[Emery]

 

[Majuh]

Here's another video explaining how LiveTrack 3.0 works:

 

[Spinelli]

At first I thought those were official PCars 2 vids. He does a great job explaining things. I love vids like this that actually delve into technical aspects so others can gain knowledge & understanding.

I've only gotten a few mins into episode 24 and I've already learned quite a bit. For example, all the smaller looking puddles - the ones which are spread out in a large amount all throughout the track and usually off the racing line (according to the video) - are purely graphical so they have no effect on physics, however, you can still use them to judge how wet the track is because more of them show up the more wet the track gets and vice-versa. That's exactly the sort of info I was looking for.

Looking forward to watching the rest.