Jerks at vertices - CoasterBuzz

Weird phenomenon I'm having. I get strange jerks in motion at every vertex on my Talon recreation. The phenomenon appears even in stock elements, and all of the curves are visible smooth even at extreme zoom in's in the editor.

Check it... ftp://ftp.popw.com/Talon.nltrack

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Jeff - Webmaster/Admin - CoasterBuzz.com
"As far as I can tell it doesn't matter who you are. If you can believe, there's something worth fighting for..." - Garbage, "Parade"

It's always going to appear smooth in the editor when you zoom in really close, but actually being a bit further away will give you a better idea what the over all curve of the track is. You've got some pretty tight corners with sharp turns in there. I'd run around in 3D in the editor and look at the most problematic control points from many different angles.

-Ride_Op

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See, I've done that. Smooth lines everywhere. The immelman is the best example, it does "the jerk" at the top and bottom of it, but when you inspect it, there's no reason for it to do that.

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Jeff - Webmaster/Admin - CoasterBuzz.com
"As far as I can tell it doesn't matter who you are. If you can believe, there's something worth fighting for..." - Garbage, "Parade"

You may need to play with the control points a bit to adjust the curve where it's jerking. If the control points are too close or misaligned you end up with an abrupt jerk rather than a curve. If they are too far way then the control point acts more like straight track. The trick is to find the balance so that there isn't much of a change from one segment to the next.

-Ride_Op

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But look at the track for yourself... those conditions aren't present.

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Jeff - Webmaster/Admin - CoasterBuzz.com
"As far as I can tell it doesn't matter who you are. If you can believe, there's something worth fighting for..." - Garbage, "Parade"

I have. I made some changes and sent it back to you. The jerks are there, but they're hard to spot. You'll get a sudden jerk when the track is changing radii (which is most of the time) and you haven't evened out the bezier curves. I'm not immune to this either...Vampyre Bat and Lightwave have some jerks left in them. It will always look nice and even in the editor, but when you ride it that's a different matter. It comes with practice.

-Ride_Op

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I looked at it, and sitting in the back seat, you can see they're still there. Sit in the back seat of the Montu track... it's even worse at every control point.

I've done a lot of 2D animation in After Effects and that kind of phenomenon doesn't happen with Bezier curves. It doesn't make sense. I'm thinking it's a software issue, not one of design.

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Jeff - Webmaster/Admin - CoasterBuzz.com
"As far as I can tell it doesn't matter who you are. If you can believe, there's something worth fighting for..." - Garbage, "Parade"

That happens almost all the time. It's hard to completely get rid of. The difference between 2D editing and the 3D stuff is that in 3D you end up riding exactly on the line and you can see every minute flaw in it. When you are far away or watching from an external view (or 2D in After Effects) you can't see every bump in the road.

-Ride_Op

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Visit [url=http://rideop.twistedrails.com]Ride_Op Coaster Productions!

No... because when you have the track all within the same plane, you're essentially working in a 2D world then. This is true for a flat spin or an immelman. This is a problem with the game.

Do a test track all in the same plane (side view) with a series of bunny hills. Sit in the back seat outside, inverted 4-across. When the train encounters a vertex, top or bottom of the hill, the cars "kick" over the vertex, which is to say that they swing forward in a violent motion.

If your control handles are nice and long and there's a long bit of room between the veritces, there is no way there could ever be that hard of a bump in a Bezier curve. Not a chance. These should be smooth parabolic curves and bump free.

Flaw in the game, not operator error.

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Jeff - Webmaster/Admin - CoasterBuzz.com
"As far as I can tell it doesn't matter who you are. If you can believe, there's something worth fighting for..." - Garbage, "Parade"

Ultra Coaster had it and so does Scream Machines. But it can be lessoned with enough practice. In my latest coaster Vampyre Bat ride in the back on the edge. There is very little jerking through the loop and diving loop (but there are rougher areas later with more jerking that I didn't get around to completley smoothing).

-Ride_Op

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Visit [url=http://rideop.twistedrails.com]Ride_Op Coaster Productions!

Parabolic curves don't have bumps.

That's all I've got to say about that. Design flaw.

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Jeff - Webmaster/Admin - CoasterBuzz.com
"As far as I can tell it doesn't matter who you are. If you can believe, there's something worth fighting for..." - Garbage, "Parade"

My hills seem just fine...

What I've discovered with a jerky vertice is this: try to move the vertice out a little. For instance, a vertice in a right hand turn, move it slighty away from the center of the arc of the turn. Just a tiny little move will turn an apparent smooth turn into an actual smooth turn.

Also, it's key to adjust the vertice in at all three dimensions. ie, adjust the control points in one view, then switch views and adjust again. Keep in mind that unless your control handles are horizontal or vertical on the x,y plane, a move in one view causes a move in the 3rd dimension you aren't seeing in that particular view.

Hope it helps.

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Can't this thing go any faster?

As I've said time and time again, this isn't an issue of non-smooth curves, it's the code in the simulator.

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Jeff - Webmaster/Admin - CoasterBuzz.com
"As far as I can tell it doesn't matter who you are. If you can believe, there's something worth fighting for..." - Garbage, "Parade"

Tons of people (self inclued) don't seem to have any problem with this...

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Tyler Eaves
Coastergames.net - File Downloads!
Coastercount.com - Free track record keeping!

Well aren't you just an all-star. If you could do your part to prevent the spread of e-mail viruses you'd be all set.

You know what, everyone who has tried to "fix" the problem with this track did nothing but make the vertices nearly flat. Thus, circles become ovals.

I've yet to see even one inverted track that didn't have this problem (including the included Kumba). In fact, if you can get him to admit it, Ride_Op even told me on IM that there are code problems using the Bezier curves and Ole is considering something else for the next version.

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Jeff - Webmaster/Admin - CoasterBuzz.com
"As far as I can tell it doesn't matter who you are. If you can believe, there's something worth fighting for..." - Garbage, "Parade"

Jeff, I'd appreciate it if you did not misquote me.

I never stated that there was a problem with the code, as it works just fine. Enough practice and patience will result in smooth coasters. As evidence check out the stretch from the first block brake through the end if the Immelman on my latest coaster Vampyre Bat. That section of the ride is 99% perfectly smooth. (other spots were a bit rougher, but I was a bit lazy)

As for the fixes others have tried there is a balance point between too sharp of a jolt, and very flat and oval like. Finding it takes patience, but it is there. Keep trying and you'll get it.

To reiterate, there are no code problems that I am aware of, and I never said such. If you'd like to dispute that more you should talk to the writer of the code, Mr. Ole Lange; as he can answer any questions much better than I. I don't wish to argue with you, just merely help you with building smooth coasters and to solve the "jerking" problem you're experiancing.

-Ride_Op

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Jeff, ride my coaster Blackhawk in the back. While the jerks are there on quite a few of the vertices, they are not on even close to all of them, and almost none of them are even close to the magnitude that you experience in your Talon recreation. I'm not sure what's up, but it seems to be more design than anything. In looking at your Talon track, there are tons of non-smooth curves in there, especially your vertical loop, and a lot of the turns, which sometimes have the handles too LONG, which then causes jerking when they don't line up with track from a previous vertice. Sorry, Jeff, I have to chalk this up to design.

Jman

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Jman
Webmaster: Gravibulb Coasters - Home of Professional Quality Coaster Photos
http://balder.prohosting.com/gravbulb/coasters/

If you think it's design, then you need to learn what a Bezier curve is. Bezier curves would not under any circumstances create this phenomenon on a curve with long handles.

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Jeff - Webmaster/Admin - CoasterBuzz.com
"As far as I can tell it doesn't matter who you are. If you can believe, there's something worth fighting for..." - Garbage, "Parade"

Bezier curves are NOT a magic bullet. All they are is an algorithmn designed in the 1970's to allow east plotting of curves. There is no gaurantee of smoothness or any such thing.
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