Maximum Polygons in TSRE/ORTS

[landnrailroader]

Friends,

It is (or was) well known that around 4000 polygons was a maximum for MSTS and so if you were, for example, creating a bridge or timber trestle, you would do it in sections so that any individual part or section did not exceed the max.

So do we have a similar number for ORTS/TSRE. Reason I ask is that one of my projects, for which I have the track done, is the Camas Prairie RR which was a jointly owned UP/NS line. It was connected (and still is) to the UP just west of the Joso High bridge, so I have included the line that follows the Snake River west to the junction point and I have included the UP from 10 miles or so geographically north of Joso to the connection. The CPRR is famous for its many timber trestles, some very large, so much so that it is commonly referred to as the "railroad on stilts". And the Joso High Bridge is 3000 feet long +- with MANY steel towers & connecting girder spans. Such a bridge is a lot of repitition so it is not all that hard to create with TSM but the poly count goes up raplidly, so-----??

Jerry Sullivan

[eric]

I've had a few objects in the 20,000 poly count for ORTS, so I don't think there's a fixed upper limit like we had in MSTS or TSRE.

To the "what is Jerry trying to do" part of the equation.... I'm a believer in making my bridges somewhat modular i.e. decks, spans and trusses in 5m, 10m, 20m, 25m and 50m sections that can match up to track sections, and having the supports be separate objects.

For a timber trestle, I'd probably build a common set of bents/piles and repeat that every 10m or so. The bottoms get buried in the terrain, and the visual effect is usually no worse for the wear.

An example I did to help Todd out with the Kate Shelly bridge in Iowa is here: https://trainsim.com/forums/forum/ge...shelley-bridge

[pwillard]

I agree, we can make our models a LOT more complex now without worrying about it. The modular approach does make sense to me, though, as there is a lot of repetition in bridge spans. The repetition of shapes is a good thing, as it can mean fewer "draw calls" since the shape and texture will likely be ready and waiting to be blasted to the screen.

[landnrailroader]

Pete, others,

I use sections like Eric described on most of my efforts. In the case of truss spans, I always use a seperate span for each space between the supports. Usually there is little choice about this since truss spans may be of various lengths & heights in the same bridge. The most complex trestle or viaduct I will expect to tackle will be the mentioned JOSO bridge but the L&N bridge at Henderson, KY is not far behind. That one is more than 2 miles in length with a series of trusses over the Ohio R. and many deck girder spans on concrete pillars in the approach span to the north, which is also on a grade and curve. At least JOSO is straight except for the last few spans at the geographically south end.

Gee, Pete, I just noticed your location of Cumming, GA. Not all that far from Jacksonville. "Yellowdog" is the only member that I have ever met in person and that was real early in the game, like 2003. I know where Eric lives now - been under his property many times, the last in summer '78.

Jerry

[ebnertra000]

I made a set of bridges, including timber trestles, a few years ago. I made the spans 5m long, as that's roughly the distance between bents. That can get a bit tedious for longer bridges, but ideally you only have to build it once. I don't know if it'll work for you, since they're based on ca. 1900 NP plans, but they may provide some food for thought if you want to build a modular timber trestle

https://trainsim.com/forums/filelib-search-fileid?fid=87145

[eric]

Short sections also help deal with curves... Curved bridges are usually straight beams slightly angled and offset at the support points.

I've found some 1d and 0_5d track sections wind up being close to the length as my predefined spans and supports. With a slight tweak of the rotation you can fix the alignment "well enough" to look like it was designed that way,

[landnrailroader]

I have several timber trestle parts that I have used in various routes. Since I use M-tracks, most of my curves will be measured in degree of curve. With this methodology, a 2 degree curve would be laid out in the field by placeing a transit at a point on a curve, turn the transit 2 degrees in the direction of the curve and then extend a 100' chain (ruler or tape) 100 feet and mark the next point on the curve. With this in mind, and with the realization that 50 feet is a common length of plate girder, though if you have a track chart or a clear image on Google Earth, you can measure the length. Now feet/3.28 gives us the meters, so 100 ft. is 30.48 meters, 30 meters is good enough. If we have a 50ft. plate girder, then we need to turn it roughly 1 degree. I would use the more precise translation functions to do this. Timber trestles are often 16 feet between bents. Tower viaducts typically have 40 ft. plate girders atop the tower, and 70-80 feet between them. Where I had to be careful is that there are subtle differences between steel tower viaducts on the Milwaukee Rd., N&W, and Tennessee Central, and those on Southern, L&N, or UP (JOSO). The first group usually do not have horizontal members in the tower except at the top and (usually) the bottom, where as those in the other group have horizontal members at all levels. Ain't it fun to do all this----??

Jerry

[eric]

It actually is. It's a virtual erector set...

Sent from my SM-S911U using Tapatalk

[landnrailroader]

Eric,

At least you remember what an Erector set was. I got my first around age 7, and eventually had the #12 set which was the last one made. I still have it, in it's original red metal box. My son had it for some years and then gave it back. More recently he put a image on FB showing his grandchildren playing with his Lincoln Logs sets of which he had several. That is another item that disappeared long ago. Worst curse that ever was is the cell phone. Now kids don't want anything they can't use on their phone.

Jerry

[eric]

I suspect Lego made both Lincoln Logs and Erector sets somewhat obsolete.

Before Lego, my favorite was the Kenner Girder and Panel building set. My kit didn't have enough to do the Sears Tower, but I sure tried to get close.

[oper190]

my favorite was the Kenner Girder and Panel building set.

I had that too, along with Lincoln Logs, and two Erector sets, an newer version and a hand-me-down older one. Ah the memories and fun.

[pwillard]

There was also FischerTechnik from around the 1960's that still seems to be going strong thanks to S.T.E.M.