Same point in track suddenly reading very different forces.

I had a problematic spot in a track I'm working on recently. It's a bit of a crazy flyer that has a few unique elements, and as a result I've had some issues with the forces in a couple of spots. Maybe that's why some of these elements don't tend to be used on flyers...

There was one spot that took a solid couple of hours of work to fix up, and even then I could only get the Gs reduced to -1.5 at the worst spot. (I say "worst," because it's not really meant to be an air moment.) I'm positive this was the number, because I rode it in EVERY SINGLE ROW in the sim, in both the far right and far left seats at x0.25 speed. Just goes to show what a problem spot it was, I guess.

I should be clear that I did make some changes to the track before testing it today, but they were about 2000 feet down the line from the spot in question. When I tested it today, it pulled -3Gs in the front far right seat.

What gives? Does anyone have ANY idea why this could be happening? Are flyer forces reliable in the simulator? I know the G-force comb doesn't display the right "sort" of force, but displays the correct number (or correct estimate anyway) but I thought the forces were true in the simulator. Regardless, I can't imagine why it jumped up... or down... another 1.5Gs.

Talk about frustrating!

On a slightly different but related note, I've noticed when building vertical loops on flyers (starting on rider's backs, facing down at the apex) I sometimes run into high negative forces as well. For the life of me, I can't figure out what exactly causes this (i.e. shape, speed, etc.) so I just have to fiddle around until I fix it. Do vertical loops on flyers such as Skyscrapper and the Vekoma models pull high negative Gs? Does anyone know the most common cause of TOO high negative Gs on a flyer vertical loop? Should it be more circular, more clothoid? Something in between? Does it need to be taken particularly slow or particularly fast?

Sorry for all the questions. No one would know that I've had NL1 since the second year of its existence and am an honest-to-goodness coaster enthusiast. I just didn't play NL1 anywhere NEAR as much as NL2, plus I've only just started using the in-game FVD a whole lot more.

TIA....

A quick note about the built in FVD console. Make sure you build your entire track before leaving the editor, because the console will "forget" what the speed and forces were when you left off. It can be a pain getting it to line up correctly when you come back.

I have had similar anomalies like that before. while testing my track "Enigma" I got a rollback, and never figured out how and never had it happen again. I think it has something to do with changing the speed of the simulation back and forth, like the program gets lost or confused.

Plantoris based on what you said I went back into the sim to see and I think you might be on to something. It was better when I didn't fool around with the simulation speed but it's still reading a little high... I wonder if I tried to edit it,made it worse, and gave up but i really didn't think so. Is it possible it got shifted slightly if I edited another section close by based on NL2's building mechanics, or should that really not happen?

NightwindElf wrote:

A quick note about the built in FVD console. Make sure you build your entire track before leaving the editor, because the console will "forget" what the speed and forces were when you left off. It can be a pain getting it to line up correctly when you come back.

I'm sorry, am I missing something here? I frequently use the FVD over multiple saves and re-openings, as well as often build the track in many different FVD-designed segments. I actually use a combination of hand building and the built-in console (I'm a Mac user running NL2 on bootcamp, so I couldn't let hand-building go completely since that was all I knew for so long), but usually what I'll do whenever using the console is to simply design as much track as I want in there and just add seconds as I go along. Then I'll stop and either build a little more by hand, or simply select the last vertex and open the console again starting fresh.

With regards to setting the speed, I just fiddle around based on what the Speed Comb estimates at the end of the track. Sometimes I'll even take advantage of being able to set it as whatever you want, and sometimes purposely set it a couple MPH off to get a tighter track with higher Gs more easily (for example) and I just know that the forces I'm selecting aren't exact. In these cases, it's more of a "force contour track shaping tool."

I haven't run into any problems smoothing out transitions either through a combination of moving vertices, rotating the track, checking the radius comb, using the depumper etc. 99% of the time this works just fine (for me) and without tooting my own horn, I feel that I'm able to cover up the transitions pretty well in most instances. I have also learned a couple of tricks that make this easier.

Maybe I'm misunderstanding the problem you're describing?

[mkingy]

That can happen due to the way that track is formed - how far back is changed will depend entirely on your track and node spacing too.

As for the high negative G's, I presume you mean when the train is "upside down". In this case you'll be pulling up to -1 G as you aren't freefalling due to the inherent shape of the loop

[TTD03]

NightwindElf wrote:

A quick note about the built in FVD console. Make sure you build your entire track before leaving the editor, because the console will "forget" what the speed and forces were when you left off. It can be a pain getting it to line up correctly when you come back.

Unrelated, so you are saying that you have to complete the entire coaster track and connect it before you can leave the editor, or it will get screwed up the next time?

Now that I'm re-reading, I think he just means that you can't open up the editor again and continue building an element that you didn't yet finish in the FVD. But if you actually create the element there should be no issue upon reopening (??). Normally you can tell the built in FVD use a set of previous points, but you lose this when closing the editor.

Mkingy, but I feel like the big negative spike in loops and half loops happens RIGHT at the Apex, and that's what I'm not understanding. I get the -.6+ on the downward half at the point where actual passengers are upside-down as you're not in free-fall but I'm pretty sure these spikes I'm seeing are happening right at the crest of the loop and I'm simply having trouble visualizing why that is.

[TTD03]

Yea. that sounds more realistic to me.