One of the great features in RF2 in my view is wet weather. In the Formula SimRacing leagues both WC and ACE feature real time real world weather using the weather plugin. It became clear on Saturday in the Ace event that there is an issue with the track not drying at all off the racing line. We had a thrilling qualifying but the race of 90 mins ended with the track off the very thin racing line still completely wet. This is quite unrealistic and not helpful for the racing. In real life drying comes from evaporation from the sun, drainage off and through the road base, the significant air turbulence from the cars and also from the sheer heat coming off them. Currently in the simulation it seems only the tyres clearing the water is functional. It would be really really helpful if ISI could see their way clear too creating and implementing an algorithm that perhaps simply used ambient temp and time to dissipate the currently indestructible standing water. As we at FSR try to take it to the other sims and further establish RF2 as the most accurate and dynamic way to race online it will be a big help. The stream was very exciting anyway. Watch it though and you will see what we mean. I will drop the link in soon. Thanks David O' Reilly Marketing Director Formula Simracing. Edit: I did the above quickly from a pad. I want to add that the wet weather feature led to the most exciting and immersive qualifying session I have seen in a sim. One driver switched to inters and moved up the grid, Others followed. In the race drivers successfully used the water offline to cool the tyres. Here is the stream.
That's unexpected for me; previously I had measured a verrrrry slow evaporation rate (in practice, you'd probably consider there to be no evaporation without some figures to check with), but I thought a recent build or two had made changes in this area. I'm assuming you were using build 1084?
Yes Lazza we were on 1084. RR was at 100%. There was a recent change that prevented RR progression messing with the drying on the racing line. That seemed to work well. But yes a little tweak to a "general track drying" once rain has ceased would go a long way. I am advised the in the last VWEC race it was still wet 3 hours after the rain stopped.
It's all probably still tied to the realroad rate somehow. Put realroad rate to 15x and you'll notice that the road gets saturated with water much quicker than with say 0.1x. I assume the same is the case for evaporation, as it would make little sense to have only one part of the wet road dynamics tied to RR rate.
I was thinking of this from build 1052: "Weather and wet saturation speed fine-tuned." I must have been hoping evaporation was tweaked so badly that I somehow read that into it. So maybe not
Not so sure. RR only does stuff where cars drive. So there is only a RR dynamic on that bit. Evaporation wise? there doesnt seem to be any.
RR rate setting has other effects than just where the cars drive, because it affects the rate at which the road gets wet. So presumably it also controls the rate at which it dries (outside of driving line as well).
Yes there is evaporation. A wet track with no cars eventually will be completly dry. Ofcourse ambient temperature and air humidity has an influence on evaporation rate. but those two are not implemented yet. BTW : I don't know if the weather plugin controles the road wetness. If it is... Maybe that's your culprit.
No, plugins have no control over that. Can set rain and cloud, and the pointless wind (not sure on humidity right now, been a while since I looked), but unfortunately can't directly set track wetness (or run a virtual period of rain / no rain between sessions, which would be great for recreating a time delay or sessions on different days... but now I'm off track, excuse the pun) Build 1080 I think actually mentions the RR weather effects being slowed in higher time accelerations (so you could run a dawn-to-dusk race over an hour but not have light rain saturate the track in one lap, or a single car completely dry the racing line in the same time), so I don't think time multipliers can help with evaporation. *by the way, when I tested some time ago I found a rain rate of something like 0.2% (0.002) was enough to keep track wetness steady. The build note I quoted above would suggest a higher value would do the same now (slower saturation), but perhaps evaporation itself hasn't changed at all.
Great video to show that evaporation does occur--too late and too slowly with a sudden burst right at the end of the cycle.
The whole discussion we're having is about it being too slow. As for 'sudden bursts', don't trust what the graphics show, the actual figures can be (and usually are) changing at a constant rate but the track wetness can appear to have stages to it. To some extent you need that to help you see that there is some dampness or wetness present, a smooth graduation would make it difficult to tell.
I suspected in my earlier post that this whole issue is more about people using wrong realroad time scale values. I now did the following experiment: loaded session with rain, let the road get saturated to max, saved realroad. Then loaded the rainy realroad profile into a fully dry practice session, 0 AI cars. Test 1: 15x RR time scale, forwarded session time by 10 mins. Wetness level: 60% Test 2: 0.1X RR time scale, forwarded session time by 10 mins. Wetness level: 97% Conclusion: you can already control precisely both rate of water build-up and evaporation with the existing RR time scale parameter.
I speeded up the video. Due to that you don't see the light raindrops very well. It stopped raining after the full course yellow +/- at 1:12 in the video. It did rain for 2,5hours. The non driven part of the track dryed up in 1,5 hours.
That is a helpful test. Thanks The one thing that crosses my mind is that those numbers seem to indicate evaporation might be too slow. Eg test 1 saw 150 minutes real time cause a 40% drop in wetness with no rain at all. That extrapolates to a dry track after no rain for 375 minutes. 6 hrs 15 mins for track to dry. So maybe the rate needs to increase. Why not increase RR you may wonder? Well RR x1 seems to work well with rubber build up over a race. Seems a shame to need accelerated rubber build up to get a realistic evaporation/drainage rate.
I would say, without knowing temperature, humidity, sun occlusion and the type of asphalt (and probably more variables) it's quite difficult to say what is realistic.
As said before, there are many other variables in sim AND real life, which affects water evaporation and/or drainage. There are no two independent tracks in the world, which shares same "realistic" water evaporation rate. Let's list few of these variables: track sewerage system - how good/bad its designed or is it even exist or working at all asphalt type - gravel/tar ratio, gravel particle size, surface frazzle rubber buildup - surface smoothness affects water absorption and evaporation (shameful or not) track geometry - uphills/downhills, bankings etc. time of day/season - sun angle and distance temperature and humidity - track surface temp & ambient temp + air humidity car types and number on the track - high downforce cars with wide tyres vs. low downforce cars with narrow tyres tyre type and compound These are just very few and very simple variables. And I'm not even going to more deeply physics and chemistry, which has great affect on this. In the end every single track has their own invidual characteristics, including water evaporation/drainage. Rubber buildup is just one variable from dozens other. I'm just wondering how you can define "realistic" and call other kind of evaporation/drainage unrealistic and shameful..? Sim itself has pretty good adjustments of this feature already, which give you possibility to adjust it to your own preference.
Yeah it seems a little slow if we take x1 rate as "standard". With x1 on my non-extrapolated test it took about 30 mins to clear 10% of the water with no cars.
The mod matters also when determining the length of this particular piece of string. It's up to the mod maker to decide what a 'fully wet' track means and adjust the tyres to suit. This could make a full wet track effectively 'monsoon' conditions that are completely undriveable, or a quite wet track that produces 20% slower laptimes. Then x% evaporation in y minutes is a different rate in each scenario. In my tests, which were quite a while ago, I judged the rate of evaporation in terms of the amount of rain required to keep the track state steady. % rain is obviously also quite subjective, except that at the time anything less than about 10% rain was effectively invisible unless you sat still and stared at something very dark, at which point you could actually see some raindrops, barely. Having to have less than 1% rain to avoid eventually flooding the undriven track seems very unrealistic in that case (in general). If the build notes are correct, and 'rain saturation rates' have been adjusted, that would probably mean you can use a higher rain percentage than before to match the rate of evaporation, plus recent builds have made light rain more visible (in a slightly ugly way, but sometimes form over fashion so ok). There's also the matter of whether the evaporation rate is linear (constant at different track wetness - I'm guessing so), and I think any testing needs to be done at 1x RR rate because stonec's figures above and the recent build notes would suggest the wetting & drying are not directly proportional to the RR rate. (ie 15x is not 150x faster than 0.1x)
