Sailing with slicks - the rain is broken in rF2 thread

So this thread came up after the last GT3 Endurance race of SRC. It was a race with changing conditions, where lots of the time there was standing water and actual puddles, very enjoyable. There are quite a few problems I have posted about before, but since then nothing was improved and after this race a new massive problem was found.

Burst drove the first half of the race with slick tires, even though the entire track was covered with standing water and spray coming from the tires (even slicks), and they were doing competitive lap times...

With ACC and AMS2 already having pretty good rain implementation it's just a matter of time before rF2 is not the best at that anymore either.

Here again a list of whats broken/missing in the rain of rF2:
- Slicks work too well
- Slicks generate spray
- Track gets fully wet with a low percentage of rain (drizzle)
- Rubbered in line STILL doesn't get less grip when wet
- Dry line still generated from the middle of the car, not the tires (just like the real road)
- STILL no aquaplaning
- What you can feel in IRL is that standing water has more roll resistance (who would've guessed), this I dont think is in rF2
- Tires still dont cool down enough if at all when cooling down off the dry racing line (probably due to the fact track temps STILL don't affect tire temps
- Grass far too grippy in the wet. (wet grass should be very very very slippery)
- Kerb/white line/astro turf has too much grip when wet (debatable but still something I want to get out there)

With all of this said, although I love rF2, I can't remember the last time S397 added or improved something in the physics. I think it's time for S397 to show what they can do in the physics department, now that other sims are getting better and better. Keep up the good work though

 

Awesome, keep it on. I have big interest about physics of wet racing.

I am also leaving this here: https://forum.studio-397.com/index.php?threads/roughness-of-tdf-works-wrong.62503/

I have decided long ago to continue on this once S397 gets stable with new UI and competition system. I think that won't happen this year, but perhaps good time to start talking about rain in general.

 

Mod dependent. Simple realtime params.

Should they not?

Track temps do affect tyre temps, it's just the track temp doesn't change. The increased temperature conduction to a wet track is another realtime parameter, so mod dependent.

The rest I agree with, and most have been talked about for many years.

 

Yeah any tires on a wet surface will produce spray when driven over at speed, regardless of tread or not.
Also it's my understanding that Kerbs/White Lines do have properties associated with them to be more slippery in the wet, this is of course something the Track Modder has to implement.

 

I think the thing with the spray is that when you get spray while driving you shouldn't be able to drive that fast to get spray at all (with slicks)
So in rF2 you can drive that fast in the rain with spray (which means standing water on the track) with slicks shouldn't be possible.

 

Indeed, the material properties in the .tdf define surface roughness which should facilitate this, and I believe do for painted surfaces if done properly. I don't think I've seen guidelines (from the devs, or from a user who had success) on ideal values for different surfaces, and all discussions I'm aware of were unable to arrive at suitable values for worn aggregate for example - which would at least partially allow for proper wet driving lines. So we're halfway there...

That is basically true (though surely it's still possible to drive fast enough at least in a straight line, and possibly even on corners depending on the amount of water and speed, to produce spray with slicks), but the initial statement is very black and white which I don't think is productive.

 

The roughness parameters doesn't work as intended, at least thats based on my attempts to make surfaces that would give good grip on dry, and poor grip when wet as in contrast with opposite kind of surface that would have worse grip in dry, but better in wet. However, maybe I was not doing it properly, but I have not seen anyone else.

Speaking of spray, the slick tires will without any doubt remove a ton less of water literally. However, I wonder how much of water gets blown out by underbody aerodynamics in high downforce cars ? Anyway, there are no parameters in tires that would control amount of water being removed.

 

The performance of any tyre is created in that particular tyres files and slicks can certainly be made to work or not work in any mod in the dry or wet online and offline (the racing line) but the creator needs to set that up properly to reflect how it should work, if the tyres are not realistic fair enough but up to each modder or the Studio to create the correct settings or the settings they wish the tyres to have.

 

Sure, they would produce less spray. But saying "Slicks generate spray" in a list of broken things suggests you think they should produce no spray.

I'm sure I saw the quote at the time, but now I can't find it. I believe what he said is in line with the idea that track temps are static in the physics, rather than that the tyres are not losing any temperature to the track. If you can link to it I'd be interested though.

 

IIRIC I have been doing some tires that cools down faster on the wet, it is just a separate heat transfer parameter for wet surfaces.

One interesting thing about wet tire performance, is that higher pressures pushes aquaplaning speeds further up. It should be indeed an interesting as in one hand car could be driven faster without hydroplaning, on the other hand reduced contact patch size and load sensitivity would take some grip away where it is not that wet.

The rolling resistance part to me is very interesting. I wonder how much of it comes with increasing depth of water layer, also I wonder if there is any rolling resistance increase due to surface being just damp - just thin water film. I even wonder if surface with very thin water layer could possibly reduce rolling resistance... stuff to think about...

I looked at some rain with slicks footage

The view is obscured, but it doesn't look like fronts pick up much water.


Quite a lot of spray can be observed, but I'd say it could be because aerodynamics. Group C once has crashed there because it sucked up loose manhole cover.


Interestingly its possible to see quite a bit of spray here, even with these small wheels and slow speed.

 

Just look at this. This is what I mean with rF2 is falling behind. Physics aside, this is what spray should look like. Many many levels above rF2. These are graphics that actually matter and add to the racing. Visibility gets worse simply due to the rain. Spray gets generated from the tires, rain lights work very good and actually have a use.

 

@mantasig : rolling resistance on wet track is related to water displacement. You need to have a thickness of water over the surface to suffer this drag. Moisture or water level that barely fill the cavities in track can and will affect grip but remaining there, should not suck energy from the vehicle. This water can be projected upward due suction or contact behind the tire.

 

We have drops on the windows and car body. And every time I'm driving at 80kph in my real car with drops streaming up the window, I wonder why the ones in rF2 are so stubborn... (not that the AMS2 vid above seems much better in that respect - and those winds look cyclonic!)

 

Yeah that's a red flag weather. Not much purpose aside show off what the graphic engine. can do.

 

uhm, purpose might be having fun, but knowing this forum, that term is non existent

Anyway, doesn't change the fact that it looks much better

 

rFactor 2 made a big and important step with the updated rain graphics, back at about two years (i guess) ago. Which improved not only the grapfics side, but made driving in rain usable at least. There was some info that physical improvements, like aquaplaning following up, but never happened. They also mentioned some improvements of particle system more recently, which might include rainspray as well (don't know for sure).

I see a general problem with S397, that development of codebase doesn't seems to be at a similar pace as compeditors. For me it looks like S397 is only able to work on two areas of codebase simultaneus at max.
Maybe t's not affortable to maintain a bigger team here, dont know.

 

I suspect the implementation of the current water droplets and ribbles is a concious one and limited by gameplay concepts. In rF2 there currently is no need to even use the wipers and you can drive along even at night with heavy rain wich sounds wierd and as if the system is broken. I reported this a few years ago, but it's obvious why it is implemented as it is. People with low end PCs or people who just want to have a vision advantage are able to completely switch off the rain effects, so people who use it will obviously have a disadvantage. In that regard the current system is a compromise, as it gives people using the effect their own advantage - they exactly see when it starts raining and especialy how much. All in all there is a lot of room for improvements for the visual side of things, but I think that's further down the line and should be improved with a complete revamp of the whole particle system. Rooster tails don't look like rooster tails, they look like engine blow ups. And as Remco said, there is no rain spray from the front tires, wich is pretty important in OW racing with spray getting into the cockpit. Still, I am allready glad that we got what we have now as there weren't even those effects with ISI.

That said, I am not sure if there is a fundamental problem with how the slicks work in the rain in general. In the competition system there were quite a few races with changing conditions and it was a fine line with the Tatuus to manage the right time for changing tires or to manage the car to the finish and gambling on dry tires. There certainly is a threshhold on how long you can stay out on slicks, but there comes a point when it get's undrivable with that car and you basicly start skating around. The difference to modern GT3 cars is that they have TC and ABS wich makes it kind of easier, but they obviously should get to the point aswell when it doesn't work anymore. ACC has nailed this pretty well indeed and you can really feel the wheelspin through the water layer even with TC.

 

The level of spray,in Rfactor 2 is way too much. Even driving at 10mph,way too much spray is produced. Also the tracks do not correctly visually represent how wet it is. I love the idea of having dynamic weather,but every time it rains in Rfactor 2 the experience is immersion breaking . I hope this can be fixed.

 

sorry if this is completely ot, but what's the point of this whole forum if s397 devs never answer anything, or intervene in discussions?
I am on every sim forum, this is the only one in which I have yet to see someone directly involved in the game in it.