aaron886 Posted March 3, 2017 Share Posted March 3, 2017 (edited) This post is directed toward Belsimtek, but also ED. (Hi Yo-Yo! Save us!) This is intended purely as constructive criticism for an issue that I believe seriously degrades the quality of flight modeling in DCS. It may be argued that this video demonstrates silly aerobatics, but it's worth noting that this is not a request for a niche feature, but rather a bug fix. It's also worth noting that aerobatics servers are typically in the top 2 or 3 most populated servers, and this issue is not new. Other users (particularly two aerobatics groups, Virtual Horsemen and Virtual Black Diamond Jet Team) have brought up this issue in the past, but the cause was unclear and not thoroughly researched. The threads quickly devolved into hearsay and confusion. I hope this will help clear things up and force some positive changes to the dramatically affected F-5 module, and others by both BST and ED. The short version is this: the calculations presently employed for ground effect in many DCS aircraft have an unintended consequence. Because they use ed_fm_set_surface (or an internal equivalent,) the calculation of proximity is affected by aircraft and static objects. However, a strange side-effect exists: it seems that the calculation is affected by objects above the flight model, causing uncommanded changes in lift in such a way that can only be described by seeing it. It is NOT: Stall behavior Network latency Malfunctioning sticks Crappy flying (I edited all of that out) Special thanks to Rock, Aeroshell, Tango, SE, and others who contributed to the understanding needed to make this post. 2 of the formation flying tracks: https://1drv.ms/u/s!AmN3Bf1HOeoRmQVRDrvjKzkLw7E8 Edited March 3, 2017 by aaron886 6 Link to post Share on other sites
aaron886 Posted March 3, 2017 Author Share Posted March 3, 2017 (edited) Here is the problem described in code from another EFM developer with the same issue: http://pastebin.com/3aYw7cTF He says that the issue is most likely related to having a "negative altitude" below the object in close proximity. The lower the altitude, the greater the drag reduction. Edited March 3, 2017 by aaron886 Link to post Share on other sites
VTB_Bingo Posted March 3, 2017 Share Posted March 3, 2017 Excellent video on showcasing the bug issue. Hope they fix it :( [sIGPIC][/sIGPIC] Virtual Thunderbirds, LLC | Sponsored by Thrustmaster Link to post Share on other sites
NineLine Posted March 3, 2017 Share Posted March 3, 2017 I've pointed Yo-Yo here to see if he has any insight, will report as he sees fit, but great report. Looks like you guys were thorough, and constructive. Nice work. Forum Rules • My YouTube • My Discord - NineLine#0440• **How to Report a Bug** Link to post Share on other sites
aaron886 Posted March 3, 2017 Author Share Posted March 3, 2017 Thanks for the help! Not sure who wrote the F-5E FM, but I would love for them to see also, of course. :) Link to post Share on other sites
cofcorpse Posted March 3, 2017 Share Posted March 3, 2017 (edited) Great find, guys! We'll investigate this effet thoroughly and fix it. Thank you! :thumbup: Added: Video is totally awesome! Edited March 3, 2017 by cofcorpse Link to post Share on other sites
VH-Rock Posted March 3, 2017 Share Posted March 3, 2017 Thank you so much for putting this together - it's explained far better than it has been previously. I really hope that this can be fixed :) Virtual Horsemen - Right Wing (P-51) - 2008... Virtual Ultimate Fighters - Lead (P-47) - 2020... Link to post Share on other sites
Jowen G. Bruère-Dawson Posted March 3, 2017 Share Posted March 3, 2017 Good job ! Hope the devs can fix this too. Good luck to them. Link to post Share on other sites
9.JG27 DavidRed Posted March 3, 2017 Share Posted March 3, 2017 awesome find! i never wondered, but now watching that video, it explains quite a couple of mid air collisions with my buddies during the years.... unfortunately i cant rep you for this. Link to post Share on other sites
RyboPops Posted March 3, 2017 Share Posted March 3, 2017 That was really cool to watch. Nice work! Link to post Share on other sites
Ala12Rv-watermanpc Posted March 3, 2017 Share Posted March 3, 2017 Amazing job guys, loved the Top Gun reference :lol::lol::lol::lol: Hope this can be fixed asap! Take a look at my MODS here Link to post Share on other sites
aaron886 Posted March 3, 2017 Author Share Posted March 3, 2017 Great find, guys! We'll investigate this effet thoroughly and fix it. Thank you! :thumbup: Added: Video is totally awesome! Good to hear! Thank you for the quick response, I'm looking forward to the fix. :) Link to post Share on other sites
Caput_58 Posted March 4, 2017 Share Posted March 4, 2017 Wow. Amazing bug report. That being said, please don't fix the bug for helicopters. Or at least, make sure objects below still count for ground effect. Landing on buildings and bridges would be awful hard without it. Link to post Share on other sites
Deezle Posted March 4, 2017 Share Posted March 4, 2017 Is this the same bug that's been in 2.0 since release? Where you fly under a bridge or try to hover a helo under a canopy and it begins to float? Intel 9600K@4.9GHz, Asus Z390, 32GB DDR4 2400MHz, EVGA GTX 1070, Custom Water Cooling, 970 EVO 500GB NVMe, 2TB of Mechanical Storage 34" UltraWide 3440x1440 Curved Monitor, 21" MFD monitor, TIR5 My Pit Build, VKB Gunfighter Pro w/WH Grip, TMWH Throttle, MFG Crosswinds W/Combat Pedals, Cougar MFDs, Custom A-10C panels, Custom Helo Collective, SimShaker with Transducer Link to post Share on other sites
Dino Might Posted March 4, 2017 Share Posted March 4, 2017 Great investigation, report, and video. Off topic: Who are the virtual aerobatic teams that fly the F5, and are any looking to bring on board newbies? I've been wanting to start trying to fly formation with people and only dipped a toe in the VA servers. F5 is my favorite module, and I'd love to get into this, but would need some serious practice/training. Back on topic: So, is this something that can be currently fixed by each player by modifying game files? I'm guessing it will break integrity check, so we're up a creek unless ED puts an official fix in place, right? Link to post Share on other sites
kam Posted March 6, 2017 Share Posted March 6, 2017 Is this the same bug that's been in 2.0 since release? Where you fly under a bridge or try to hover a helo under a canopy and it begins to float? Not just 2.0, 1.5 as well.. https://forums.eagle.ru/showthread.php?p=2628613#post2628613 Intel 5820k | Asus X-99A | Crucial 16GB | Powercolor Devil RX580 8GB | Win 10 x64 | Oculus Rift | https://gallery.ksotov.co.uk Patiently waiting for: DCS: Panavia Tornado, DCS: SA-2 Guideline, DCS: SA-3 Goa, DCS: S-300 Grumble Link to post Share on other sites
Talisman_VR Posted March 6, 2017 Share Posted March 6, 2017 Very nice work. Thank you and all involved for time and effort. Happy landings, 56RAF_Talisman 56RAF_Talisman Spitfire! 'That's no aircraft, that's a bleedin' angel' Link to post Share on other sites
PSV_Tango Posted March 8, 2017 Share Posted March 8, 2017 Thank you for all the effort put in the video Aaron! Thanks as well to the devs who gonna take care of this ;) :) Leader of the Virtual Patrouille Suisse Since 2010. High and slow, fast and low. Intel i9-9900k | 32GB RAM | MSI RTX2080 8GB | HP Rerverb G2 | WarBRD Base | WinWing Set Link to post Share on other sites
Emmy Posted March 8, 2017 Share Posted March 8, 2017 Brilliant Video! Just curious: Does this same "negative ground effect" happen if jets are in a mirror formation with opposing lift vectors? [sIGPIC][/sIGPIC] http://www.476vfightergroup.com/content.php High Quality Aviation Photography For Personal Enjoyment And Editorial Use. www.crosswindimages.com Link to post Share on other sites
9.JG27 DavidRed Posted March 8, 2017 Share Posted March 8, 2017 this thread really needs the attention of ED, and not only BST. just tried this with the 109, and flying under a bridge will cause the same yaw effect like shown in the vid with the P51. and why yaw at all? thats something which makes me even more convinced that there is something seriously flawed with the rudder and yaw effects in dcs. also not too reassuring that its users who find that bug, which is probably existent for a couple of years. wonder how many other such flaws are deeply hidden in the FM. Link to post Share on other sites
Deezle Posted March 8, 2017 Share Posted March 8, 2017 Not just 2.0, 1.5 as well.. https://forums.eagle.ru/showthread.php?p=2628613#post2628613 Yeah, it showed up in 1.5 after the 2.0 release. Just begs the question why this is only getting looked at now over a year later, after it's already been posted about. Intel 9600K@4.9GHz, Asus Z390, 32GB DDR4 2400MHz, EVGA GTX 1070, Custom Water Cooling, 970 EVO 500GB NVMe, 2TB of Mechanical Storage 34" UltraWide 3440x1440 Curved Monitor, 21" MFD monitor, TIR5 My Pit Build, VKB Gunfighter Pro w/WH Grip, TMWH Throttle, MFG Crosswinds W/Combat Pedals, Cougar MFDs, Custom A-10C panels, Custom Helo Collective, SimShaker with Transducer Link to post Share on other sites
NineLine Posted March 8, 2017 Share Posted March 8, 2017 Yeah, it showed up in 1.5 after the 2.0 release. Just begs the question why this is only getting looked at now over a year later, after it's already been posted about. Doesnt matter, its getting looked at now, please keep this thread clean for any new information on this bug please. 1 Forum Rules • My YouTube • My Discord - NineLine#0440• **How to Report a Bug** Link to post Share on other sites
USSR_Rik Posted March 15, 2017 Share Posted March 15, 2017 aaron886 and your group - many thanks for your video and additional materials and analysis! El pueblo unido jamás será vencido DCS World 2.5: Часто задаваемые вопросы Link to post Share on other sites
aaron886 Posted March 17, 2017 Author Share Posted March 17, 2017 Thank you for fixing this, and quickly too! I'm very impressed with the response from ED and Belsimtek. It's been a very satisfying process. Link to post Share on other sites
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