NL2 Riverview Bobs

Tonight's work has been on TA2 plus courses 1 and 2 which lead in and out of the turnaround. I've built this section in a separate park so I can get both courses absolutely parallel with each other as NoLimits has a nasty habit of making its straight sections drift away from true when built on diagonals. If the courses are not perfectly placed, then the subsequent internal fan curve of TA3 will not be correctly placed and this will cause all sorts of unwanted problems.

If you look at the picture below you will see that the curve banking ends far too early. This is due to the way in which the game calculates bent spacing on curves. My maths checks out, and I've put in the correct value, but the computer's maths in response does not and it hasn't built them where it should. It's a bit frustrating working out how to beat the computer at its own game, but I'll get there eventually. Note that I raised the coaster by five feet for the photo to show the base of the curve.

[Coasterkidmwm]

The catwalks looks like it's in a valley almost. Does the train go down or up that curve.

Ascending and descending turns are, I think, pretty hard to create, as cars tend to get jerks at each end.

Coasterkidmwm wrote:

The catwalks looks like it's in a valley almost. Does the train go down or up that curve.

Down. This is the high front turn on the right of the station. I think the way to beat the game will be to calculate the bent spacing for the first 180 degrees and then let the game work out the remaining 29 degrees for itself.

Last night I discovered that there was a bent height missing from my spreadsheet, meaning that the final bent of the straight section leading into the turn was at the wrong height. This fixed the problems with the curve. I'm still going to experiment with the closer spacing based on a 180 degree arc, and whichever is closer I will use.

The banking for this turn is incredibly pumpy when ridden in the simulator, whereas on the POV video on YouTube it's perfectly smooth. I'm not sure why this is. At any rate, there's no red marks on the g-force comb, which is reassuring.

[Coasterkidmwm]

Maybe you need to lock the banking. NL2 has a habit of rocking the banking back and forth sometimes.

That means the continuous roll mode should be used for a quick roll, not for gradual curves with low roll rates. Thanks for the great tips!

I will try the same method on my tracks.

Some nice pictures for you tonight. All three were taken with the coaster raised five feet off the ground so the base of the curve is visible. First off, much of the bumpiness was caused by an error in the bent spacing caused by the computer, and I had to increase this to an even 8'-0" to get the correct number of nodes and spacing. Second, the strict function on the roll nodes actually made the bumpiness worse by increasing the tilt of the track around it. The smoothest result was obtained using a "less is more" approach where I kept the 24 degree banking on the first three roll points and the 48 degree maximum banking near the bottom, and then removed all the other roll points and left the computer to work out a more gradual transition from 24 to 48 and back to zero degrees. For now I'm going to leave the roll as per the Church blueprint - every bent accounted for. Once the ride is complete I'll go back and see if I can tolerate the idea of removing some of the roll points for the sake of a smoother ride in NoLimits. It is clear from building the ride in the simulator that the fault is with the computer and not with Church, because in the POV video the banking is the same but the ride doesn't jerk around the curve.

The following pictures show the curve and its exit. You can see how it is much improved from my last version. In the first I've left the banking on every bent. In the second and third I've used the "less is more" approach. The third photo was a glamour shot I took to show how steeply the curve drops from left to right. Note that the flat section will become the first midcourse brake run. Oh, and the g-force comb shows no red spots at all.

One ideal section was built!

I completed building both runs and the turnaround tonight, and couldn't resist testing it. In a word: wow. This is going to be one fast ride! No red g-forces but the pacing is crazy - you get just enough time to breathe on the midcourse and then the train dives back into the maelstrom. In terms of stats it reaches 30 mph at the bottom of the high front curve, and 30 mph again on exiting the internal fan curve of TA3! Just under two thirds of the way around the ride and the train is going only 10 mph slower than at the bottom of the first drop

[mkingy]

Awesome sounds like it's all starting to come together a bit more now!

Right now it's all about the bent spacing on TA1. The revised banking has proved somewhat of an improvement, but the real test of whether the curve is right will be caused by the interaction between TA1 and TA3. The exit of TA3 goes UNDER the exit of TA1, so the clearance has to be safe. Speaking of clearance, by adjusting the radius of the second curve on the roll out, I was able to get the two straight sections either side of the station perfectly placed and perfectly straight. The one passing the entrance platform barely clears the queue line!

^ Let me say that yours is, day by day, beginning to take shape!

I was hoping to have some more photos up for you last night, but although I was able to determine the correct bent spacing for TA1 and TA3, while raising the height marks between the two turnarounds on the rebuild I made a mistake which threw off my alignment: that of deleting unnecessary nodes either side of a piece transition. It???s okay to do this, but you have to have the subsequent track in place first otherwise when you build the next piece it will be out of true. In short, I have to have enough of the rest of the ride done before I can raise any height marks. At that point it was just too late at night for me to do any further work before today. However, I can say that TA3 now fits perfectly within TA1, and again there are no red transitions in the g-force comb. The last problems with the track angles et cetera relate to TA5 and the end of the ride. Once that???s done it *should* be a straightforward job.

The jerks you're seeing in NL would likely show up if you ran a graph of the roll points. I know Lake Compounce's Wildcat had those issues before GCI redid it. It's masked in a real ride by the wood tracks and wood framed trains being able to flex in the transition, whereas in NL you're on a fixed path so any imperfections in that path are obvious.

In any case this is some great work. It's cool that you're taking the approach of building based on the bents vs the centerline which I don't think very many people do. I've done it with a few things and it's a ton of work but I do like the outcome in the long run, although I get in the habit of not finishing anything. If you wanna PM me that would be cool, I have a decent amount of experience in this type of building (although I handbuild straights and FVD++ curves in NL1 and then port it over) and a pretty good understanding of structure/bent spacings. Could probably learn a good amount from each other.

Freddie wrote:

The jerks you're seeing in NL would likely show up if you ran a graph of the roll points. I know Lake Compounce's Wildcat had those issues before GCI redid it. It's masked in a real ride by the wood tracks and wood framed trains being able to flex in the transition, whereas in NL you're on a fixed path so any imperfections in that path are obvious.

Now, why didn't I think of that? That will save me a lot of time with all the other curves.

Freddie wrote:

In any case this is some great work. It's cool that you're taking the approach of building based on the bents vs the centerline which I don't think very many people do. I've done it with a few things and it's a ton of work but I do like the outcome in the long run, although I get in the habit of not finishing anything. If you wanna PM me that would be cool, I have a decent amount of experience in this type of building (although I handbuild straights and FVD++ curves in NL1 and then port it over) and a pretty good understanding of structure/bent spacings. Could probably learn a good amount from each other.

I'm not quite sure what you mean by building based on the centreline, but I felt that since the blueprints were in front of me I didn't have any excuses for lack of precision and going by the bents was the best way to achieve as much accuracy as possible. The most frustrating thing has been getting the number of nodes correct in the turns, as when I put the mathematically calculated node spacing in, that's not what NL2 renders. A good example of this is the high front turnaround. Spacing is calculated as arc of the curve, times pi, times radius, divided by 180, which gives the length around the curve, and then divide that by the number of bents on the blueprint. For the high front turnaround, the nodes should be spaced 7.25 feet apart. Instead, I have to use an 8 foot spacing, otherwise I get 15 or 16 nodes around the turn instead of 14. I've also noticed that if you get NL2 to generate a long straight section, say 200 feet, with a node spacing of 10 feet, there is a point fairly on in the section where bent spacing stops being exactly 10 and becomes 10.0395 or some small decimal like that. It seems NL2 is careless with its calculations. To combat this I've created straight pieces of various lengths in a separate park and then adjusted the node spacing manually and set the nodes to strict. If I don't, then I get pieces of supposedly straight track which drift sideways along their length and whose bent spacing isn't even. Tedious but necessary.

When most people create a recreation, supports are an afterthought or cosmetic, so things like having sections take place within the correct amount of space isn't really of concern. They create a track centerline and supports work around that. Now that's not entirely bad with an original ride, as a lot of real rides (at least CCI whom I'm most familiar with) will have the first or last bent of a section (a bridge can affect this as well) be an odd spacing. But when it comes to a recreation, I don't think most people have the patience to count out bents to get within that few foot tolerance (usually within 4.5').

What you're experiencing with NL2 is a big frustration to me and largely why I've stuck to the NL1 editor. NL2 puts a lot of weight into making a smooth track at the expense of control on our end. The whole B spline system as I understand it is all based in relativity....basically we're telling NL2 where we want the track to go and it's generating around that. That's fine for modern steel coasters, where there is a much higher degree of freeform involved, but for most wood coasters, where you're basically working with circles/straights, it's sort of an uphill battle. I kind of gave up trying to get a circular shape out of strict nodes and just went back to my old methods. I also noticed the straight thing (again, I think NL2 is trying really hard to smooth any transition into or out of a tangent which is why that happens) early on and that's what brought me back into NL1. The downside is being married to roll in NL1 where it's independent in NL2, which I still haven't found a totally reliable way of taking advantage of (setting basic roll in NL1 and then deleting points in 2 seems to do alright but sometimes it's a little awkward coming into or out of a roll).

I don't know how much faith I'd put into the autosupporter. I think early on you said you weren't into the idea of custom supporting, but if you want that level of accuracy I don't think auto generating is going to get you there. As far as the generation being off a very marginal amount, I wouldn't worry about that too much. Most real carpentry has a tolerance of 1/16" and you're well within that with those numbers, not to mention footings don't always get poured exactly as they should which is why a lot of supports end up off center on them. Just giving you an excuse if you want to use it

For me, I'm stuck between a rock and a hard place over the autosupporter. On straight sections, Church used a 10 foot bent spacing with the horizontal braces 5 feet apart on centre. This makes it very easy to estimate the heights of his coasters, assuming the ground they are standing on is flat. The autosupporter's maximum bent spacing is nine feet. Having autosupports which do not have the same spacing as the nodes is a bit disappointing, but on the other hand, I simply cannot face building over 340 bents by hand right now, and that doesn't include all the horizontal braces! I kind of feel it's a choice between the recreation being finished and being 100% accurate. I think for me, the main thing I want to get right is the scale of the track because that's something which is often off in other recreations I've seen. The blueprint shows a ride which was diminutive in stature (either 64'9" or 66'9" at the top of the lift) but which punches well above its weight in terms of intensity and g-force. With all the rumours that it would be unsafe to build today, I kind of want to set the record straight and see how badass this coaster really was. So far the indications are that it is still safe, but it's not tame at all.

Incidentally, my obsession with accuracy isn't limited to counting the number of bents. Because the prints have been photographed and then reduced to fit onto two sheets of A4 for the book, I got out my ruler and a calculator to work out how many millimetres was equivalent to 10 feet. When I do come across unevenly spaced bents, I can then work out how long the section really was and create new pieces accordingly. This was needed for getting the lift hill the right length as the first piece isn't an even 10 feet but is closer to 6 feet. It's also been useful in calculating the radius values of curves where the draftsman has forgotten to include the figures on the plan!

NL1's autosupporter is 10'/6', which would get you closer. Not sure how much work it would be for you to get it back into NL1, though.

Been there done that with digital calipers on prints...just be sure the perspective is correct, otherwise you've got a whole new set of issues lol.

Having sorted all but the final jink onto the brake run, I discovered a fatal flaw...the brake run is on the wrong side of the lift in my recreation! This is because the turn onto the lift curves about three degrees too far. I'm going to have to delete everything right back to the start of the lift to correct that. ARGH! This weekend I'm away, so it'll be next week when I can tackle it properly.

I managed to find time to play with the recreation this weekend anyway. After a lot of tweaking there are still some distortions in the blueprints which I just can't solve, and I think it's the case that I won't be able to solve them without seeing the original prints at their original size. For now, though, the layout is near enough. The lift hill went up tonight, and the rest will go up tomorrow or the day after. Hopefully this time I am actually on the home straight...

Freddie: Can you change the spacing of the vertices in NL1 or do I have to delete the extra ones manually?

^ I suggest posting more photos of the sections you have been working on, so we can visually see your "already promising" progress. Many thanks for adding your activity details.

Let me say that you can do it!

I spent four hours tonight trying to solve the puzzle of those stupid curves. In the end I decided it was a fool's errand and I should just get on with what I have already. It's close enough. The plan is to raise up the end of the ride first so I can check it before dealing with the start of the ride. Then I'll work my way backwards until everything connects as it should.

Edited to add: Freddy, I'll keep the spreadsheet when I'm done. I can't port tracks back into NL1, but I can certainly build them to already calculated specs. I may need a holiday first, though!

^ Good to find better solutions for those curves!

I have one last idea for the internal fan turn and then I'm calling it quits for the last time and going back to what I have. In brief, the problem is this:

The nearest I can get to what the plan actually shows for TA1 is a 262 degree curve. This puts the crossover in roughly the right place. However, I then struggle to get everything from there to the internal fan turn of TA3 correctly placed due to distortions in the blueprints making it hard to make correct measurements. I've had to effect a compromise of a 265 degree curve and then everything else is close enough. However...

Having the first curve go further round than it should means there is less clearance for the exit of TA3 to go underneath it. TA3 also suffers from distortions and while I measure a curve of 198 degrees, a 193 degree curve seems more realistic. But then the clearance really is impossible even though it's then possible for me to have a correct-ish curve to take the train alongside the lift. At that point it becomes six of one and half a dozen of the other: either I sacrifice a few degrees of the fan turn to make the exit curve and clearance work, or I stick with the fan turn's current dimensions and put up with clearance which works but an exit curve which is wrong.