New exhaust plumes detaching from ship

[Diziet Sma]

I've noticed this several times now.. in every trunk release since the new plumes were created (including the latest nightly, r5547), if you come to a stop and then rotate your ship around, you'll often see the plumes floating in space ahead of you. Touch the throttle and they jump back where they belong.

(three plumes in this screenshot because I'm flying a Pitviper)

[cim]

How do you manage to come to a stop and still have exhaust plumes at all? When I stop the plumes shrink to nothing.

[Svengali]

Maybe -> https://bb.oolite.space/viewtopic.php?f= ... &start=235?

[cim]

Ah, I see. Probably fixed in 5548, then.

[Diziet Sma]

How do you manage to come to a stop and still have exhaust plumes at all? When I stop the plumes shrink to nothing.

I confess that had me confused too.. no explanation for it.. but that's how it happens..

[gizmo]

It still happens in R5556.

Edited to add: and with R5564 too

[cim]

Try r5567 tomorrow and see if that fixes it, then. I think I know what's happening here, but since it doesn't happen to me, I can't tell if the fixes are working.

[gizmo]

Looks like R5567 fixed it.

Thank you

[CommRLock78]

This is not exactly related (not trunk and not detaching plumes) but I figured since it does have to do with plumes I'd post here. I've noticed for a while that if I'm traveling a fairly long distance "in system" the exhaust plumes sometimes take on some odd characteristics (mis-shapened and squirrelly looking). For a while I was thinking it had to do with ship maintenance, but since I've seen the weirdness and docked without need of overhaul, I'm starting to think something else is going on.

[Smivs]

...the exhaust plumes sometimes take on some odd characteristics (mis-shapened and squirrelly looking).

Well, that's better than skunky-looking!

[Commander McLane]

This is not exactly related (not trunk and not detaching plumes) but I figured since it does have to do with plumes I'd post here. I've noticed for a while that if I'm traveling a fairly long distance "in system" the exhaust plumes sometimes take on some odd characteristics (mis-shapened and squirrelly looking). For a while I was thinking it had to do with ship maintenance, but since I've seen the weirdness and docked without need of overhaul, I'm starting to think something else is going on.

The clue is in 'if I'm traveling a fairly long distance "in system"'. If you do that, everything around you becomes 'squirrelly looking'. The reason is simple: floating point precision. The bigger the numbers your CPU has to crunch, the less precise they become. What becomes bigger in the outskirts of a system are of course the coordinates. Around the planet your ship and everything else can be placed with a precision of many numbers behind the decimal point. The farther out you are, the less decimals can be used. Thus everything becomes a little shaky, with visible jumps between two neighbouring coordinates. The effect kicks visibly in already at a distance of about 3,000,000 to 4,000,000 meters from the system centre. It gets worse the farther out you get.

[cim]

The effect kicks visibly in already at a distance of about 3,000,000 to 4,000,000 meters from the system centre. It gets worse the farther out you get.

And the exhaust plumes are particularly vulnerable to this effect. They can start looking noticeably turbulent in the aft view - though not "wrong" as such - even just at the planet (~500,000 metres from the origin).

It's on my list of things to look at, but there's no quick fix.

[CommRLock78]

This is not exactly related (not trunk and not detaching plumes) but I figured since it does have to do with plumes I'd post here. I've noticed for a while that if I'm traveling a fairly long distance "in system" the exhaust plumes sometimes take on some odd characteristics (mis-shapened and squirrelly looking). For a while I was thinking it had to do with ship maintenance, but since I've seen the weirdness and docked without need of overhaul, I'm starting to think something else is going on.

The clue is in 'if I'm traveling a fairly long distance "in system"'. If you do that, everything around you becomes 'squirrelly looking'. The reason is simple: floating point precision. The bigger the numbers your CPU has to crunch, the less precise they become. What becomes bigger in the outskirts of a system are of course the coordinates. Around the planet your ship and everything else can be placed with a precision of many numbers behind the decimal point. The farther out you are, the less decimals can be used. Thus everything becomes a little shaky, with visible jumps between two neighbouring coordinates. The effect kicks visibly in already at a distance of about 3,000,000 to 4,000,000 meters from the system centre. It gets worse the farther out you get.

Thanks Commander McLane for the detailed response - explains the problem perfectly!

The effect kicks visibly in already at a distance of about 3,000,000 to 4,000,000 meters from the system centre. It gets worse the farther out you get.

And the exhaust plumes are particularly vulnerable to this effect. They can start looking noticeably turbulent in the aft view - though not "wrong" as such - even just at the planet (~500,000 metres from the origin).


It's on my list of things to look at, but there's no quick fix.

I'm sure you have bigger fish to fry, but it'll be nice to get fixed when the chance arises .

...the exhaust plumes sometimes take on some odd characteristics (mis-shapened and squirrelly looking).

Well, that's better than skunky-looking!

LMAO - I would have to say so!

[maaarcooose]

Running trunk and testing out my new ship.



When I'm on full power the exhaust plumes are not attached to the ship. If I run on half power they are at their origin point.

Is this normal behaviour?

Also I noticed that when I hit the injectors, the plumes detach from the rear of the ship and flare up large then settle down to their small purple style and reattach to the ship. Go back to standard full throttle and they are behind gain.

I can video if need be.

!m!

[cim]

It's normal for them to move back a little as the ship accelerates, because of the way exhaust positions are calculated, but it shouldn't be that bad. What's the ship's max (non-injector) speed?