4d coaster help

[AmIEgged(]

So i'm making a 4d coaster where the drop is sort of like a pretzel loop. Near the end of the pretzel loop, when it goes back up and backwards, I want the seats to be facing in front ( at the horizon) the whole time it's going back up and backwards.
Here is how I want it to be
http://steamcommunity.com/sharedfiles/filedetails/?id=520965163

But at one point, the seats decide to do a whole flip instead of staying facing the front.
http://steamcommunity.com/sharedfiles/filedetails/?id=520965228

Here are the 4d parameters i've set. I've tried so many different things to prevent the seats from flipping. I tried switching the values from negatives to positives, the placing. Everything. All that does is just change the spot where the seats are going to flip.

http://steamcommunity.com/sharedfiles/filedetails/?id=520965353

http://steamcommunity.com/sharedfiles/filedetails/?id=520965503

http://steamcommunity.com/sharedfiles/filedetails/?id=520965737

Thanks. Any help is appreciated

[Ride_Op]

4D parameters are a bit tricky and take a bit of understanding to use. The number indicates the amount of rotation from the starting point. At 0 degrees the seats will be upright and facing backwards on straight level upright track. The flip rotation amount is always relative to this starting point and relative to the track, not absolute to the world. You can flip 270 degrees forward and backward from this starting point, which is 3/4 of a rotation forward or backward. These values are always relative to the default starting point. The 4D roll node has an L shape to indicate the direction the seats will be facing at that point on the track.

Screen 3 shows -260 and screen 4.5 shows -1, meaning there is 259 degrees of flip between the two. The flip you are trying to do would require flipping in the other direction, something you can't do now since you're starting at that extreme.

To accomplish what you're looking to do, earlier in the track work on getting the seats into the same position, somewhere around +100 degrees (-260 + 360 = 100). Then you'll be able to roll to 0 and the seats will flip in the direction you want.

-Ride_Op

[AmIEgged(]

Originally posted by Ride_Op:

4D parameters are a bit tricky and take a bit of understanding to use. The number indicates the amount of rotation from the starting point. At 0 degrees the seats will be upright and facing backwards on straight level upright track. The flip rotation amount is always relative to this starting point and relative to the track, not absolute to the world. You can flip 270 degrees forward and backward from this starting point, which is 3/4 of a rotation forward or backward. These values are always relative to the default starting point. The 4D roll node has an L shape to indicate the direction the seats will be facing at that point on the track.

Screen 3 shows -260 and screen 4.5 shows -1, meaning there is 259 degrees of flip between the two. The flip you are trying to do would require flipping in the other direction, something you can't do now since you're starting at that extreme.

To accomplish what you're looking to do, earlier in the track work on getting the seats into the same position, somewhere around +100 degrees (-260 + 360 = 100). Then you'll be able to roll to 0 and the seats will flip in the direction you want.

-Ride_Op

So for the drop I changed every single value from the beginning to positives instead of negatives. Now the problem is that only delays the problem. After that part I have a turn and another sort of loop. The last 2 4d parameters on the loop are similar both around -240. But the last 4d parameter makes the seats flip but the one before it doesn't. Also if I change the last parameter from -240 to a positive. Then the seats flip at the parameter before it. How does me changing one parameter affect another one?

[Ride_Op]

Each parameter will set the seat orientation at that point. If two points in a row are set to the same value the seats will not flip in between. Changing any particular value only affects the seat orientation at that node, not the rest. If there is a change from one node to the next, the seats will adjust to the next node.

The challenge is that you have a limited amount of seat flip to play with, only 540 degrees, or 1 1/2 flips. 0 is upright when the train is upright, giving you 270 degrees or 3/4 of a flip forward and 270 degrees or 3/4 of a flip backward. And remember, this flip is always in relation to the track, not the ground. If you never change the seat flip and send the track through a loop, the seats will go upside down with the train just like on a normal coaster.

There are 3 ways to have the riders upright:

Train on top of track, seats at 0 degres: Riders upright facing backward
Train below track, seats at +180 degrees: Riders upright facing forward
Train below track, seats at -180 degrees: Riders upright facing forward

It might help to study a real 4D coaster's rotation. This link will take you to a video of a real 4D coaster. At 2:39 of the video you'll see an uncut shot taken from a camera mounted to the train. This will let you see how the seats flip throughout the track. Notice that there is only so much flip the seats can do in one direction before they have to flip the other direction:

Dinoconda Video with stationary on-train shot

At 3:46 the seat flip is at 0 degrees and the riders are upright facing backward.
By 3:51 the seats have flipped to -270, as far as they can go in one direction.
3:53 to 3:57 the seats go from -270 to +270, flipping 540 degrees or 1 1/2 flips, the maximum amount of movement at one time.

Keep looking at the video and you'll see that the seats don't do lots of flips. The ride uses a combination of track flips and rolls along with seat flipping to create creative inversions.


-Ride_Op