CgTalk:FXWars! Catapult! (Trebuchet) Challenge:1

#42

Here’s my trebuchet, only the model done so far… I really need some help with the dynamics, can’t get it to work properly!

:slight_smile:

My trebuchet

#43

Yep, a lurker here as well, hoping to try this one out! looks very intriguing. Never used maya’s dynamics as of yet, but i am hoping to give them a shot! GL to all.

#44

As for weights you would do well to use real weights, if you want to keep everything in an accurate ratio. Do some research and it shouldn’t be too hard to find (haven’t looked into it yet myself but I’m going to shortly). For instance, I believe that some of the largest medieval trebuchets used counterweights in excess of 2000lbs (1 ton). Stones could probably reach a couple hundred pounds.

Also, some people continue to refer to a trebuchet as “a catapult”, which it isn’t at all. Inventiveness will be awesome to see what people come up with, but operating on the assumption that basically a trebuchet is a catapult is wrong and violates the rules of the contest. Maybe Roberto is willing to bend the rules and allow catapult style machines but I’m just working off what’s been posted so far. To clarify, a catapult operates off of a resistance or spring method, pulling an arm back which flings forward based on tension, this is the classical movie artillery. A trebuchet flings up and around using a counter-weight and only the force of gravity. Personally, I think trebuchets are far cooler, it’s amazing how powerful and elegant they are.

#45

[i]Actually, a trebuchet IS a catapult according to me.

Catapult comes from the greek “cata- + pallein” to poise a weapon before hurling. Which is actually what a trebuchet is doing as well.

Trebuchet comes from old french “trebucher” which means to “overthrow”, referring to the lifting of the arm caused by the counterweight.

Perhaps the catapult you refer to, the one with the arm that’s wound up using a spring mechanism has another more specific name, but according to me they are both catapults.[/i]

#46

dear whiterabbit

You seem to be implying that the contest requires a trebuchet to be specifically built, however, according to the original rules, i dont think this is the case…

"THE CHALLENGE:
Build a working catapult, that should destroy a small brick wall in a short animation.
"

So I take it to mean that any kind of catapulting weapon can be built. I hope this is correct?

cheers

leach

#47

Although it is specified that it should be a trebuchet…

CgTalk:FXWars! Catapult! (Trebuchet)

And if you check out the reference that mr threadstarter added, it’s all trebs, no other catapults… I think we should just stick to trebs, so we can do the other catapults on another challenge :slight_smile:

#48

I agree with with WhiteRabbit.obj, catapults are resistance and tension based, whereas trebuchet’s are counterweight. Makes total sense to me.

#49

Check a dictionary:

www.dictionary.com

Trebuchet: A medieval catapult for hurling heavy stones.

#50

Hi,
i think a trebuchet differs from a mainstream catapult in that it uses a slingshot like mechanism to hurl the object. The beam and counterweight is just one possible solution to power the slingshot.
Cheers
Srek

#51

Indeed, what I am saying is that theres a lot of different kinds of catapults:

Catapults:

  • …
  • …
  • Trebuchet
  • …
  • etc…

Like a treb is an apple and catapults is fruit…

#52

FOR THOSE LOOKING FOR TEAMS i POSTED THIS THREAD:

TREBUCHET SIGNUP LIST: CLICK ON THIS THREAD those who are looking for partners/teams

And please post more topics
HERE > CgTalk:FXWars!Topics
so I can do more of these challenges.

-R

#53

How about the load release? Do we have to simulate this correctly by letting a rope slip over a hook or similar?
Would a tearing rope or a hook/handle setup be ok?

Cheers
Srek

#54

A tearing rope sounds fine by me.
The key is the simulation.

-R

#55

Wikipedia is great, in this section, it states that a treb is definatelly a catapult, but a catapult isn’t necessarily a treb, other types are tensional and torsional catapults… a ballista is a tensional catapult…

#56

Hence, my comments about catapults and trebuchets not being the same thing. A square is a rectangle but a rectangle is not a square. I just don’t want people to put a lot of work into something and get disqualified (if there is any voting of some sort) because they didn’t bother to pay attention to the rules closely enough.

#57

Hi Guys :

Cool challenge ! Very difficult though , so in my interpretation of what the Moderator is trying to say , or do , it is OK to post any kind of a simulation animation that features a “Throwing Machine” , and preferably have it destroy a wall of some kind .

This is very hard for most of us to do , I think . Some have already accomplished the task , of course , but if we let ourselves get bogged down in the details , or take this challenge too literally , we may not get to see very many results <grin> . It’s very tricky , but as the Mod has said , “the key is the dynamics” .

If someone was to post an actual dynamic simulation of a spoon flinging a sugar-cube at a wall of sugar cubes , nobody here is going to jump on them for not following the directions properly . They may not be eligible for an Emmy , but I’m sure they will receive some Conrad’s for their hard work and efforts .

I’m sure the Mod would agree that one of the goals is to see actual dynamic simulations , as best as you can manage in the time you have allotted for this challenge . Another goal might be to try and have a little fun doing so .

Hopefully we will see enough contributions on this particular challenge to inspire further challenges for years to come . What you can’t manage , or don’t have time for now , you may be able to make room for on a later challenge .

Anyway , that’s just my 2 centavo’s worth . Not trying to speak for the Mod here , but just trying to perhaps help to get us all off to a good start , having fun and pulling our hair out <G> .

Thanks & Good Simulating !
Studio

#58

The Trebuchet (or Trebucket) is distinct in it’s use of centrifugal force. The fact that it uses gravity as it’s energy source makes it unique and un-catapult-like, and very proper for a dynamic challenge. In my mind, if it doesn’t use tension for energy, and goes twice as far as one that would - it’s a trebuchet.

time’s ticking, time to start clickin’.

later - pad

#59

Guys, newbie question - why am I getting the error message “Warning: Cycle on ‘pCube75.worldMatrix[0]’ may not evaluate as expected. (Use ‘cycleCheck -e off’ to disable this warning.)” when fiddling around with dynamics, and what does it mean?

Thanks…

#60

you can ignore that warning, maya is searching for stuff in the dependancy graph, just copy the cycleCheck -e off to the script editor and run it.

#61

Found an article in the paper today that is oddly related. Human trebuchet anyone? http://www.extremedreams.co.uk/human%20catapult/

Only 1 dead so far :rolleyes: