Repository navigation
Maneuver execution of Principia node results in additional ignition at completion #2225
Description
Activity
Offhand I can't see the bug in the code. The principia node disappears, then it cuts the throttle, and that can only happen because ShouldTerminatePrincipia() goes true because dVleft has burned down, and that means Abort() should have been called which disables the node executor itself, and that should be the end of it. And it looks like you correctly hit "execute next node" instead of "execute all nodes" (looks like there might be a race condition where if dvLeft burns down before principia removes the maneuver node AND "execute ALL nodes" was pressed it might grab the current maneuver node thinking it is the next one--that is a possible bug, but you didn't hit that button).
Okay stepping through frame-by-frame this is really weird. So the visual throttle appears to throttle down smoothly. The throttle starts going down first. As the throttle indicator gets down to around 67% then the maneuver node disappears by principia removing it. 2-3 video frames later the thrust visually cuts out. The throttle is still moving smoothly towards zero the entire time, for about 20 video frames there is no engine plume animation. As the throttle hits about 30% the engine relights again, but the throttle indicator continues to move smoothly towards zero and the engine cuts out again just before it hits zero.
Engine is a Juno IV 6k Engine, which has minThrust == maxThrust so it isn't throttleable (but of course that means that anything causing a 0.01 thrust blip would relight it -- that, combined with the smooth throttle visual HUD setting enabled might explain most of the animation).
Okay I'm confused, KSP has a visual throttle smoothing feature in it, but you can't disable it. MechJeb also has a real throttle smoothing feature, and if you enable it, then it will literally mess everything up.
MechJeb Version
2.16.0.0-1644
KSP Version
1.12.5.3190
Description
Executing principia nodes in Realism Overhaul with mechjeb's maneuver planner results in an extra ignition at very end of the burn, using an additional engine ignition.
Replication Case
Video is an example of a basic Juno powered craft in LEO with a pure prograde principia burn. Video shows quick flash of engine exhaust at end of burn, and a decrement to remaining ignitions.
https://youtu.be/SWxn9HGkFlY