FXWars! Roller Coaster!: Frank Firsching

#1

Hi!

Ok, this is my first attempt on the FXWars challenges. Roller coasters are something that I really couldn’t resist. The last day I spent with trying things out and checking, what can be done in which way. This is the result:

    [Test Movie](http://www9.informatik.uni-erlangen.de/Persons/Firsching/stuff/FXWars/coaster1.avi) (500k, DivX / Xvid)

It could be a short part of the complete track. Everything in this short movie is procedural. Not only the animation, but the tracks and pillars are built automatically, too. All that is needed as input, is a curve with normals, that describe the orientation of the track. The normal vectors control the rolls and twists.

  Until I forget it, this was made using Houdini 7 Apprentice.
  
        Frank
#2

Very nice test. Looks like you just have to finish the track and send it in… :thumbsup:

#3

great!

another german dude, and the same approach as our’s… argh…

It’s going to be hard to win this contest… :wink:

keep up the good work!

#4

Hehe, the German dudes are coming!

Grüße aus Heidelberg!

André

#5

Thanks for the nice critics :slight_smile:

Sir_Vulcan: I don’t think it’s quite so easy. Till now only the middle wagon is being simulated. The others are simply offset on the curve. This morning I had an idea, how to simulate the effect of all wagons on the train. I want to change this. Additionally I need a lifting mechanism to get the train on the desired height. Plus I need some better models. They are simple stand-ins. So, still something to do.

  lalunaverte: I decided to do this approach before I saw your thread. I promise!
#6

I know - I am not complaining.

Anyways. Get back to work!

#7

WOW
:eek:
I like it a lot, It runs real smooth!

#8

Nice one Frank,
Good seeing u again working on some cool stuff.
Expect more.

Cheers NatX

#9

Hey NatX, did I motivate you to sign on to CgTalk? I noticed, this is your first post :wavey:

Here is a small update: Since I’m pretty happy with my dynamics, I concentrated on the coaster generation. My goal is a complete procedural system. Today I have managed to remove intersecting support poles. If you take a look at the image below, you see, that the system is removing one pillar, where the track is passing under another segment of the track. Also the placement of the mountings at the top of the poles now really fits to the track (before, occasionally some poles just didn’t want to match the orientation of the track)
Last but not least I have modified my dynamics to do a motorized hill climbing at the beginning. This enables me to do a complete run in one shot without any keyframe :stuck_out_tongue:

         Frank

#10

Actualy i signed in a month before you, but i always felt to shy posting here. I’m also more browsing the forums and cgnetwork to get me back inspired.

To your stuff. I like the design, are the poles generated procedural? As u said u had troubles with intersections when tracks passing underneath. I wondered why u were the ohnly one to come up with a dynamic system of a motor. I already started thinking how i would do that, as i just saw rollercoaster animations that seemed to have gravitation and movement along the path

My solution would have been a drag field that lifts the cars up with constant speed, when the coaster enters the field. Show us your playblast or rendered anim!

I like your dynamic work.

#11

How much do you get judged on how procedural it is? I think that’s going to be one of the truly remarkable things about your setup. So when are you coming to North America to work? :wink:

#12

NatX: Yes the poles are generated procedurally. I only have modeled three parts, that I pass on to the coaster-OP.

The first part will be ray’ed down to the floor and placed there. The middle part is placed on the top of the pole and the third one is oriented towards the track and placed on the middle part.
I want to mention the motor again. This was really simple, because my dynamics are just one expression for the position of the train on the path. I only added a lift-time and up-position. During lift I linearly interpolate the train position from 0 to up-position.
For the playblast you want to see, I’m currently rendering an animation. Tomorrow I will post it. I don’t have any other test movies, because my dynamics are running in real time. It is even possible to scrub the timeline and watch the train move on the track. That’s something I’m very proud of :slight_smile:

@Dante and NatX (but also every other Houdini user): I think I’m gonna put an otl of my coaster-OP on odforce and the SideFX-exchange when the competition is over.

Ok, enough said, here are some images of what I was doing today:
This is a small test coaster I build. It will not be the one I submit for the final animation.

And these are the new wagons. Additionally to the modeling I enhanced the placement of the cars. They are now mounted better on the track. Both, the front and backwheels now determine the orientation of the car.

Now, I’m thinking about the next step I should do. The scene really needs some shaders. This dull gray is looking very boring. But I also have another great idea, I would like to do (and I think the time is to short to do both, the shaders and the following idea): I would like to occupy the cars with people and animate them procedurally, too. They should raise their hands, if the coaster is going down a hill, lean into a curve, etc. I think that this would be doable (and would fit quite more to the challenge than shaders).

#13

Looking really nice and effective. Do you still only simulate one car and the others follow?
The scrubbing sounds strange. Do you recalculate the entire run from the beginning to get the actual position? Especially if you scrub backwards.

And one thing that is still missing: loopings :wink: No modern coaster without 'em.

Another thing I think would improve the looks would be dividing your poles, if they get too long. With bigger segments at the bottom.

:applause: Really promising stuff.

#14

Colts suggestions are good, but as i know you, you already have crazy loops and twists in your coaster planned.

Besides that, everything looks good and sounds great. Hope you render multiple views, as i wanna take that ride!

#15

Looking real nice Frank. As dantea says, hopefully everyone will appreciate the extra effort you’ve gone to in making this setup completely procedural…even though there’s no strict category to gain bonus browny points in with it. Perhaps, if you’ve got screen capture s/w you could post a short avi of the hda in action, just to emphasise the power of Houdini - at the very least I’m sure others will be interested in seeing this.

Looking foward to taking a closer look at the hda when you release it.

Good luck :slight_smile:

#16

@Colt: I think there’s already a loop in the first test animation movie.

@Frank: At this point, I guess you want to concentrate on what gives you the best bang for buck in terms of judging.

#17

@Colt: Yes, loops and twists will be in the coaster for the final version. My first test-video has a loop.
About your question for the dynamics: I have an expression, that computes the position of the train at time t. So even while playing forwards, the whole dynamic simulation up to that point will be calculated. I wanted to do an incremental simulation, but the evaluation order of CHOP-networks in houdini forced me to do it that way. But that’s ok, since it is running smooth, even on my old P3 800MHz. The expression itself computes the position of the last wagon, but considers the effect of all cars on the train. My first test video didn’t have this “enhanced” dynamics.
I think, that those long poles don’t look very good, too. But splitting them up at the bottom would complicate things too much. Then you couldn’t handle intersections with other poles or the track anymore. At least not so easily :wink:

#18

Here is a quick update:
The rendering finished and this is the video:

TestMovie 2

I realized, that balancing drag, gravity, etc so that the train comes nearly to stop at the hill, where the on-train-cam blends into the static-cam doesn’t look realistic. An engineer could never balance the forces with the drag in such a precise manner.

#19

great work, but it seems to be a little slow.

#20

Yeah, it does seem very very slow!
I mean it looks like you are going down almost 90°, but it’s so slow. Maybe u need to increase the mass of the coaster.
Also what is missing are the loopings and twists.
What could also help to see/notice the speed better is a cam on the very front wagon with showing part of the track. And render with motionblur. I know it costs rendertime, but for the right feeling u need it.

Cheers NatX