Hello everyone. Can someone help me with something? I try to build a custom coaster of my own but whenever I create a track leading to an upwards scale, it gets stuck as it's not fast enough. How can I prevent this from happening? Also, when I try to build ''Rolls'', it also get stuck as I can't modify the default ''Rolls''.
The basic thing to remember is that each time you go down, you can't ever get back up quite as high as you started before the drop. This is due to loss of kinetic energy due to friction with the track, air resistance, etc. So basically, your lift hill is always going to be the highest part of the track, the hill (or the top of a a loop, etc.) after the lift must be a few meters lower than the lift hill, and each hill after that must a bit lower than the one before. So as others have mentioned, you need to turn on the height markers so you can build each hill slightly lower than the one before.
In addition to just normal friction, you can get some more (and thus lose more energy) from rough spots in the track. Every little zig-zag and kink in the track causes momentary G forces that increase friction, deflect momentum, etc., and thus eat into the train's kinetic energy. To avoid this problem, carefully bank and smooth your tracks to eliminate all such kinks and unwanted bumps.
And then there are the high-G maneuvers, the radical course changes. Sharp pull-outs from drops, loops, tight turns, rolls, etc. High G forces increase friction substantially, robbing even more kinetic energy. IOW, compare a coaster starting on Hill A, going down to the ground, then up to Hill B, with another coaster with an inversion between Hills A and B. Hill B must be lower for the coaster with the inversion than without because the inversion uses a lot of energy. Thus, careful smoothing and banking are even more important for inverting coasters than others (although it's important for all of them).