Simviation Forums

I'm putting together a tractor tug pulling baggage carts. 1958 version.

Does anyone have any ideas how I can have the baggage carts properly curve behind the tractor.

I tried tagging the carts as rudders, but they all move as one unit.

I'm thinking of animating the carts as if they were flaps. Full up would be curved to the left. Half flaps would be straight behind the tug and full down would be curved to the right.

Anyone have any other suggestions?



The image shows how the baggage carts move when rudder is applied. The green boxes show how I'd like them to look.

For starters, consider that EACH cart is a rudder....

Cart 1 = rudder  - pivot point to tractor hinge.
Cart 2 = rudder.1 - pivot point to rudder rear "hinge"
Cart 3 = rudder.2 - pivot point to rudder.1 rear "hinge"

rudder is the parent of rudder.1 which is the parent of rudder.2

This *should* give you a fishtail movement.

Alternatively, using the lever_stick_l_r keyframe tags, you can use the same hierarchy to keyframe maybe a less 'violent' "fishtail".

Caveat: It's early am, I haven't had my coffee, and I have no clue if this will work.

Will this be a *.mdl file or a *.bgl? If it is going to be a dynamic scenery bgl, and you are working in Max, there are animation controlers that can be used. You should be able to make your tractor and carts follow a path (spline) "Path Constrain" for position control. Then use the "Look At" controler on each of the carts for rotation and have them look at the object in front of them. It will take some experimentation, and you may have to have a copy of the path for each object each with it's number 1 vertex in a different place, spaced equally to the distance between each objects center, but it should work in theory. Hope I explained this well enough. LOL

Lou

Thanks for the advice.

This will be both mdl and bgl. Mdl when it's the main focus of the camera shot, and bgl when it's parked in the scene.

I looked into using Go Objects but I was missing one of the compiler programs/ or I didn't know how to use it and I got stuck in the middle of the first tutorial. Not a program for beginners.

If I can get the tug and carts to look half-way decent while moving around I'll be able to film them as is, without doing any fancy post-production compositshots.

http://www.angelfire.com/oh5/3d_flightsim/page18.html

has some screen shots of how the take-off scene is coming together

Thanks Felix - even without coffee your idea still worked. If I were a mathematician I'd have to say it wasn't perfect because it still doesn't look exactly right because the trailers don't exactly flow behind the tractor. But since I'm the son of an engineer I can say,"Close enough. I can get it to work for what I need it for."

You'll get a credit line at the end of the movie as technical adviser.

I are a Son of a Engineeur - and I be won to.

But since I'm the son of an engineer I can say,"Close enough. I can get it to work for what I need it for."