Unsolved Bug Report: Jdam/Loft - physics bug
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…that’s certainly ugly looking stuff.
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Wait guys
This simply looks like a bomb detonating at release because already detecting ground
A JDam does not have a lofting release profile , if you are in DZL a jdam will release as soon as you press the trigger
So basically you release and you are hit by your own bomb
We wil check that
For me the major bug is the DZL, it should be zero if too low as the JDam cannot climb by itself ,
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I highly doubt the bomb explodes on impact.
In addition, JDAMs have a CCRP release cue so you can loft them (in BMS). And the loft will work at high altitudes. Hell, it will even work in this case if you delay pressing the pickle until the “low” symbol disappears.
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In the cockpit pov videos, I see the FPM flashing (signalling bomb release) when plane is 50 ft above water.
(a) probably that shouldn’t be possible, due to safeties in the avionics – as in normal CCRP modes… and (b) it seems like there should be an arming-delay to prevent bomb from exploding < 2 seconds later?
The acmi looks weird also … doesn’t obviously show the bomb exploding upon release … and why would it drag behind the plane like that?
Does this repro in SP or only MP?
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@airtex2019 said in Bug Report: Jdam/Loft - physics bug:
Does this repro in SP or only MP?
Check OP.
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What I see in those videos is aircraft beeing hit by his own bomb because released too low
We will check though
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@Mav-jp even though -34 says exactly that “The pickle button is hot prior to the solution cue being coincident with the FPM” and “Weapon Release Button for JDAM and WCMD: The weapon release button is hot in all applicable delivery submodes whenever the aircraft is within the kinematic release zone (RMAX1 to RMIN1) of the weapon.” , the JDAM won’t release until the A-G solution cue is aligned with the fpm marker and that happens at RMIN1. As you can see on the video below (IAM training mission KOREA), I hold the pickle well before RMAX1 and the JDAM is released only when the solution cue is aligned with the fpm marker. Exact same thing happens at high altitude or low altitude.
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@danaos75 said in Bug Report: Jdam/Loft - physics bug:
@Mav-jp even though -34 says exactly that “The pickle button is hot prior to the solution cue being coincident with the FPM” and “Weapon Release Button for JDAM and WCMD: The weapon release button is hot in all applicable delivery submodes whenever the aircraft is within the kinematic release zone (RMAX1 to RMIN1) of the weapon.” , the JDAM won’t release until the A-G solution cue is aligned with the fpm marker and that happens at RMIN1. As you can see on the video below (IAM training mission KOREA), I hold the pickle well before RMAX1 and the JDAM is released only when the solution cue is aligned with the fpm marker. Exact same thing happens at high altitude or low altitude.
Thé -34 is incorrect , jdams are released only close to kinetic solution hence when fpm reaches marker
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I don’t believe this is the case. If you refer to my original post: “(in the case of MP all clients experience the jet “losing physics-tumble” even if only triggered by one client)” … that is to say, all the client jets in multiplayer “tumble out” once this occurs, regardless of their distance from the trigger event (they are not in any frag zone). Also to note there is no damage to any of the tumbling aircraft… they are just out of control
Please see this ACMI recording, demonstrating this (observe the distant player aircraft also tumbling): https://streamable.com/amr9cl
Interestingly, reproducing it, pausing and switching to orbit cam, there doesn’t actually seem to be a 3d bomb or explosion - https://streamable.com/o7d01c
… also interestingly, trying to repro it with other munitions (LGB, dumb bombs) when you get the “low” warning, DLZ disappears and you cant drop. So it well may be the case that this is an “out of parameter” launch with the Jdam.
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@FritZ said in Bug Report: Jdam/Loft - physics bug:
I don’t believe this is the case. If you refer to my original post: “(in the case of MP all clients experience the jet “losing physics-tumble” even if only triggered by one client)” … that is to say, all the client jets in multiplayer “tumble out” once this occurs, regardless of their distance from the trigger event (they are not in any frag zone). Also to note there is no damage to any of the tumbling aircraft… they are just out of control
Please see this ACMI recording, demonstrating this (observe the distant player aircraft also tumbling): https://streamable.com/amr9cl
Interestingly, reproducing it, pausing and switching to orbit cam, there doesn’t actually seem to be a 3d bomb or explosion - https://streamable.com/o7d01c
… also interestingly, trying to repro it with other munitions (LGB, dumb bombs) when you get the “low” warning, DLZ disappears and you cant drop. So it well may be the case that this is an “out of parameter” launch with the Jdam.
Yes of all clients go weirdo it comes from a NaN spreading all over
Of this is a clear repro case that’s excellent news
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@danaos75 - believe you are seeing what you are seeing and that there is no detonation because I’m not seeing a detonation flash or water displacement in your video. Furthermore, I have a hard time thinking that your fuse will arm within 2 sec post release. But here’s something you can try, given that:
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it IS possible to loft a JDAM in RL (and the time of flight gets VERY long - trust me), and the mode of release to do it shouldn’t differ from any other mode for loft of any other free fall weapon.
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set your fuse arm time to something long - like greater than 5 sec, or to the max selectable - to force your fuse not to arm prior to impact, and try this again. Setting the arm time longer than the predicted time of fall should eliminate the issue of early burst or detonation on the water from this altitude. If not, there is yet another problem…and if you get the same result, there may actually be two problems.
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Okay
We have been unable to reproduce internally what we see in the video
Could you provide the TE you are testing and the exact procedure
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Sure thing,
Pls find TE here
Exact Procedure I followed:
1.) 2d fast forward as needed. Load in 3d with jet en-route stp 2.
2.) Arm the jet + power on the bombs + Rdr Alt on.
3.) Auto pilot + 3d fast forward to Stp 2. Allow bombs to align “RDY”
4.) Setup for CCRP loft attack on from STp2 to Stp3. Approx 500kts IAS and 80ft
5.) Cleanup HUD with Scales switch (“H” key) to see “LOW” warning clearer.
6.) On ingress to target. Ensure “LOW” shows on the HUD (between 110ft - sea level. “LOW” disappears above approx 120ft, so you need to be lower than that).7.) At 20deg on DLZ and with “LOW” warning. Press and hold pickle + pull to 20deg nose up on HUD
8.) expect bomb to come off early followed by uncontrolledly state!
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Confirm you are pressing and holding pickle before the pull?
… watching the SMS page in your vid, it only switches from “RDY” to “REL” after you start pulling. I think what’s happening is you are pulling before pressing and holding. so you’re already out of the “LOW” parameters when you press (and hold) pickle.
*Edit - https://streamable.com/hrwk5g
(video with SMS page in view) -
@FritZ said in Bug Report: Jdam/Loft - physics bug:
Confirm you are pressing and holding pickle before the pull?
… watching the SMS page in your vid, it only switches from “RDY” to “REL” after you start pulling. I think what’s happening is you are pulling before pressing and holding. so you’re already out of the “LOW” parameters when you press (and hold) pickle.
No, I didn’t hold pickle at that time because I was sure I didn’t want to release while flying that way.
Fine, now it happens. The bomb releases immediately while flying 50 ft, my take is that it considers you’re not trying to loft and therefore drops. Why does it do it to your aircraft?
If it happens to other clients on the server away from you, at the same time, there is a first problem to solve.
For you in particular, is it the same bug, or is there a different problem? The bomb might be releasing in a legit way but not do damages since not exploding. Unless it hits your aircraft back after release within these abnormal parameters? Not shown in 3D if this is what happens, there is no visible bomb in 3D nor in Tacview. But you can hear the release from the cockpit and hear a boom from outside.
11 minutes.
In devs’ hands.
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First i am unable to repro your bug , the GBU does not drop early , it drops when the FPM reaches the marker as it should
second, i dont have the “LOW” in the hud, how do you trigger it ?
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@Mav-jp said in Bug Report: Jdam/Loft - physics bug:
First i am unable to repro your bug , the GBU does not drop early , it drops when the FPM reaches the marker as it should
second, i dont have the “LOW” in the hud, how do you trigger it ?
I exactly followed that procedure plus the correction we discussed above. It triggered the LOW and everything else.
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@LorikEolmin said in Bug Report: Jdam/Loft - physics bug:
@Mav-jp said in Bug Report: Jdam/Loft - physics bug:
First i am unable to repro your bug , the GBU does not drop early , it drops when the FPM reaches the marker as it should
second, i dont have the “LOW” in the hud, how do you trigger it ?
I exactly followed that procedure plus the correction we discussed above. It triggered the LOW and everything else.
unable to trigger the LOW and unable to get the bug
the only thing i dont understand in he procedure is :
“4.) Setup for CCRP loft attack on from STp2 to Stp3. Approx 500kts IAS and 80ft”
what does that mean ?
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@Mav-jp said in Bug Report: Jdam/Loft - physics bug:
@LorikEolmin said in Bug Report: Jdam/Loft - physics bug:
@Mav-jp said in Bug Report: Jdam/Loft - physics bug:
First i am unable to repro your bug , the GBU does not drop early , it drops when the FPM reaches the marker as it should
second, i dont have the “LOW” in the hud, how do you trigger it ?
I exactly followed that procedure plus the correction we discussed above. It triggered the LOW and everything else.
unable to trigger the LOW and unable to get the bug
the only thing i dont understand in he procedure is :
“4.) Setup for CCRP loft attack on from STp2 to Stp3. Approx 500kts IAS and 80ft”
what does that mean ?
Post a video, we’ll tell you what you do wrong.