Bucic Posted September 18, 2023 Share Posted September 18, 2023 Whenever I'm revving up for takeoff the A/C shakes violently at certain moments. While testing for the infamous afterburner bug I noticed camera kicks. At that time I thought it's just a camera glitch, but it seems there's more to it after all. If not for the in-flight occurrences I'd suspect a glitch in tire contact modeling but the spotlight is on the engines right now. DCS version - ALL OB versions since december 2022 not map-specific I'm going to post a track sometime later. 1 F-5E simpit cockpit dimensions and flight controls Link to comment Share on other sites More sharing options...
MAXsenna Posted September 18, 2023 Share Posted September 18, 2023 Yeah, I've seen that too. Always thought it was supposed to be that way. The F-5 was my first module, bought in 2017.Sent from my MAR-LX1A using Tapatalk Link to comment Share on other sites More sharing options...
Bucic Posted September 18, 2023 Author Share Posted September 18, 2023 IRL if there's this kind of impulse on the airframe from the engines, the engines are goners. 1 F-5E simpit cockpit dimensions and flight controls Link to comment Share on other sites More sharing options...
VZ_342 Posted September 18, 2023 Share Posted September 18, 2023 Is this the "glitch" I saw on a YouTube video recently? F-5 going from on the deck to 40,000' in a few seconds with a roar like a strapped-on rocket engine.... If so, how do I do this!?! Link to comment Share on other sites More sharing options...
nairb121 Posted September 18, 2023 Share Posted September 18, 2023 1 hour ago, VZ_342 said: If so, how do I do this!?! Link to comment Share on other sites More sharing options...
Bucic Posted September 18, 2023 Author Share Posted September 18, 2023 (edited) Here's the video and associated track file. MTOW 80% https://youtu.be/j0v57kIAGmc bug engine force kick 2023-09-18.7z Same instance but external view. It seems that it's the G camera setting is overreacting. No such movements occur on the airframe. One last video and track - G effects on camera disabled (head bobbing disabled). Note that even with the setting disabled there are instances the pilot is "shaken in the cockpit." https://youtu.be/tlWLv4vNgg0 bug engine force kick 2023-09-18 headbob disabled.trk EDIT FINAL: Yeah, the case seems to be clear - here's what happens at engine RPM variations: 1. The in-game airframe actually jitters in a way impossible in real life. 2. Due to the huge accelerations the camera algorithm goes haywire. Here's a magnified view: YAW magnified https://youtu.be/6GdVNsg31oY ROLL magnified https://youtu.be/H9ojQmatHRw Edited September 18, 2023 by Bucic F-5E simpit cockpit dimensions and flight controls Link to comment Share on other sites More sharing options...
VZ_342 Posted September 18, 2023 Share Posted September 18, 2023 I've tried this several times, but only get a little "extra" RPM, which falls off after a few seconds. Link to comment Share on other sites More sharing options...
Bucic Posted September 18, 2023 Author Share Posted September 18, 2023 8 minutes ago, VZ_342 said: I've tried this several times, but only get a little "extra" RPM, which falls off after a few seconds. It's not the 'star chaser' bug you're after. F-5E simpit cockpit dimensions and flight controls Link to comment Share on other sites More sharing options...
Bucic Posted September 26, 2023 Author Share Posted September 26, 2023 @Flappie What are your thoughts on this? Do you need any other information? I realize it's not critical. But it's a huge immersion killing glitch that's present every single time during takeoff spool up. F-5E simpit cockpit dimensions and flight controls Link to comment Share on other sites More sharing options...
Flappie Posted November 29, 2023 Share Posted November 29, 2023 Hi @Bucic. I've watched your videos but I don't see any issue. I'm probably less sensitive to this kind of things. Here's an in-cockpit footage of a F-5 takeoff. The camera shakes with full throttle. --- Link to comment Share on other sites More sharing options...
Bucic Posted November 29, 2023 Author Share Posted November 29, 2023 Thanks for taking the time to look into it.n! The actual airframe move is almost negligible in magnitude (although it is in fact an infinite acceleration glitch). The actual issue is how it affects the FPV camera. The result is a glitch appearance you'd only expect in a multiplayer session. Not to waste your time I'll get back to you with exact time stamps of FPV glitches instead of the underlying smaller airframe glitches that are harder to spot. 1 F-5E simpit cockpit dimensions and flight controls Link to comment Share on other sites More sharing options...
Bucic Posted December 1, 2023 Author Share Posted December 1, 2023 (edited) Here are the timestamps in the https://www.youtube.com/watch?v=j0v57kIAGmc 2:04 to 2:10 two kicks, not resulting from any pitch, roll, yaw or camera input. This can be replicated even with bare keyboard configuration. Same moments in the bug engine force kick 2023-09-18.7z track file: T130.xxx to T134.xxx same two kicks Edited December 1, 2023 by Bucic F-5E simpit cockpit dimensions and flight controls Link to comment Share on other sites More sharing options...
Sarowa Posted December 2, 2023 Share Posted December 2, 2023 (edited) 4 hours ago, Bucic said: Here are the timestamps in the https://www.youtube.com/watch?v=j0v57kIAGmc 2:04 to 2:10 two kicks, not resulting from any pitch, roll, yaw or camera input. This can be replicated even with bare keyboard configuration. Same moments in the bug engine force kick 2023-09-18.7z track file: T130.xxx to T134.xxx same two kicks That video looks more like a tire losing grip momentarily while trying to hold back all that force, imo, which then gets translated into a slightly exaggerated camera shake. It appears the nose continues pointing the same direction. If you look at the pipper, it's still pointing at the same tree the whole time. I wonder if this is similar to the zero or near-zero speed friction issue a lot of racing games deal with. In those, you can sometimes see a car on a hill with the wheels/brakes locked up, but the car veeeery slowly slides down the hill. I feel watching the runway texture movement seems to indicate this is happening, but also the game seems to rubber band you back to where you were when you throttle down. In the video, watch the runway texture here at the bottom left of the canopy: Edited December 2, 2023 by Sarowa 2 Link to comment Share on other sites More sharing options...
Flappie Posted December 2, 2023 Share Posted December 2, 2023 @Sarowa You're right. Something weird happens with the tires at some point. It is very visible in external view. F-5 goes back and forth.trk 1 --- Link to comment Share on other sites More sharing options...
Bucic Posted December 2, 2023 Author Share Posted December 2, 2023 (edited) It may well be that the source is the tire contact issue but don't you guys think it's suspicious how consistently this happens around 80% engine RPM? Either way the only thing I'm after is getting it fixed so getting it pulled to the ED's issue tracker Edited December 2, 2023 by Bucic F-5E simpit cockpit dimensions and flight controls Link to comment Share on other sites More sharing options...
Flappie Posted December 2, 2023 Share Posted December 2, 2023 (edited) I'll see if I can reproduce the same issue with other aircraft types, first. EDIT: It seems they all have this strange back and forth move when accelerating with brakes on. EDIT2: I now clearly see this camera tilt move when accelerating with the F-5 with brakes on. It often happens at 72%-76% engine RPM. It's not that easy to reproduce. Edited December 2, 2023 by Flappie --- Link to comment Share on other sites More sharing options...
Bucic Posted December 2, 2023 Author Share Posted December 2, 2023 (edited) 1 hour ago, Flappie said: I'll see if I can reproduce the same issue with other aircraft types, first. EDIT: It seems they all have this strange back and forth move when accelerating with brakes on. EDIT2: I now clearly see this camera tilt move when accelerating with the F-5 with brakes on. It often happens at 72%-76% engine RPM. It's not that easy to reproduce. Back and forth smooth or a glitchy back and forth? If it's smooth it may be just to compensate for the lack of airframe-gear assembly deflection in DCS (lack of the visualisation). RL Swiss F-5E https://youtu.be/ohGpGzCIS08?t=192 Edited December 2, 2023 by Bucic F-5E simpit cockpit dimensions and flight controls Link to comment Share on other sites More sharing options...
Flappie Posted December 2, 2023 Share Posted December 2, 2023 3 minutes ago, Bucic said: Back and forth smooth or a glitchy back and forth? Rather smooth. I believe it is intended so the player can feel the tires elasticity, indeed. --- Link to comment Share on other sites More sharing options...
Bucic Posted December 3, 2023 Author Share Posted December 3, 2023 9 hours ago, Flappie said: Rather smooth. I believe it is intended so the player can feel the tires elasticity, indeed. So where we're at? Tires are out of the picture now? From my observations the initiation come from the engines. You may try a 100% MTOW with emphasis on YZ plane mass momentum (the biggest toys on pylons, then top up to 10%% MTOW with fuel). If the kick eases with that setup, then the kick has a physical source, e.g. the engines. Another case is throttle split RPM increase. Sorry for writing "do this" instructions like that but my rig is kind of out of order for now. I'm going to try to get my setup ready today. F-5E simpit cockpit dimensions and flight controls Link to comment Share on other sites More sharing options...
Tiger-II Posted April 4 Share Posted April 4 I think it is an attempt to model tire flex against the thrust. You are, after all, pulling the aircraft against the brakes. I used to see glitches in RPM, but not so much recently (I think it was fixed some time ago). When you saw the glitch in your video, I did notice #2 RPM changed very slightly and fell behind #1. Motorola 68000 | 1 Mb | Debug port "When performing a forced landing, fly the aircraft as far into the crash as possible." - Bob Hoover. The JF-17 is not better than the F-16; it's different. It's how you fly that counts. "An average aircraft with a skilled pilot, will out-perform the superior aircraft with an average pilot." Link to comment Share on other sites More sharing options...
Bucic Posted April 4 Author Share Posted April 4 @Tiger-IIThTiger-IIThis topic is about the impact glitch specifically, not the tire flex. The tire flex effect I understand and appreciate it was put in place even without the associated visualisation. F-5E simpit cockpit dimensions and flight controls Link to comment Share on other sites More sharing options...
Tiger-II Posted April 8 Share Posted April 8 On 4/4/2024 at 11:14 PM, Bucic said: @Tiger-IIThTiger-IIThis topic is about the impact glitch specifically, not the tire flex. The tire flex effect I understand and appreciate it was put in place even without the associated visualisation. Does your sim glitch/stutter at all? Accelerations can be screwed up if the sim is running slowly or stutters. Motorola 68000 | 1 Mb | Debug port "When performing a forced landing, fly the aircraft as far into the crash as possible." - Bob Hoover. The JF-17 is not better than the F-16; it's different. It's how you fly that counts. "An average aircraft with a skilled pilot, will out-perform the superior aircraft with an average pilot." Link to comment Share on other sites More sharing options...
Bucic Posted April 8 Author Share Posted April 8 7 hours ago, Tiger-II said: Does your sim glitch/stutter at all? Accelerations can be screwed up if the sim is running slowly or stutters. No, that's the only thing glitching and my setup is 100+ FPS capable. Apart from AI WW2 wingmen which is, again, a separate issue. Not to mention the behaviour can be triggered on demand consistently by commanding specific engine RPM. F-5E simpit cockpit dimensions and flight controls Link to comment Share on other sites More sharing options...
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