Sorry your browser is not supported!

You are using an outdated browser that does not support modern web technologies, in order to use this site please update to a new browser.

Browsers supported include Chrome, FireFox, Safari, Opera, Internet Explorer 10+ or Microsoft Edge.

Dark Physics & Dark A.I. & Dark Dynamix / "Executive Desktop Toy" needs help {DP]

Author
Message
Codger
16
Years of Service
User Offline
Joined: 23rd Nov 2002
Location:
Posted: 30th Dec 2006 20:34
I saw one of those executive desktop toys that have 5 steel balls suspended using sting from a frame. On the real thing the balls on the end are the only ones that move as the energy is transfered through the middle balls.

I tried my hand at simulating it in DP and it half works. Occasionally the energy is transfered through to the end balls but usually they wave together.

Any suggestions

Happy New Year

Codger



System
PIV 2.8 MZ 512 Mem
FX 5600 256 mem
BatVink
Moderator
16
Years of Service
User Offline
Joined: 4th Apr 2003
Location: Gods own County, UK
Posted: 3rd Jan 2007 10:26
I considered this earlier, but never got around to trying it.

I had a mess with your code, but failed. In the pursuit of the answer, here's what I thought/found...

PHY SET MATERIAL STATIC/DYNAMIC FRICTION
Maybe you need these to make sure the spheres react properly to the collision

PHY SET SKIN WIDTH
I set this to 0.0001, 5 times smaller than the default. The theory here was that for this to work, the balls must be well and truly touching.

MATERIAL - must be like steel! Not sure of the settings.

I changed the MakePendulum() routine, and added an extra value for the position of the top of the "strings". I wondered if tapering them in towards the middle would help. It didn't work, but it did give different results. Now, all 4 balls move together when hit. Not the desired result, but maybe it holds some clues on how to acheive this.





NeX the Fairly Fast Ferret
14
Years of Service
User Offline
Joined: 10th Apr 2005
Location: The Fifth Plane of Oblivion
Posted: 3rd Jan 2007 22:30
Maybe the physics simulation simply isn't that good.


Since the other one was scaring you guys so much...
Cash Curtis II
14
Years of Service
User Offline
Joined: 8th Apr 2005
Location: Corpus Christi Texas
Posted: 4th Jan 2007 05:10
It worked with Newton, and Dark Physics is better than Newton, both in accuracy and speed. I think that it will work if set up properly, but will take some very fine tuning.


Come see the WIP!
Codger
16
Years of Service
User Offline
Joined: 23rd Nov 2002
Location:
Posted: 9th Jan 2007 20:07
I really think the issue has something to do with the joints, they are all "very loose" in all the demos that TGC used to demo the joints i see the same thing. In fact if you over stress the joints by applying "too much force" they all react as if the objects are held together by springs

Cash

Do you have a demo of this in Newton?

System
PIV 2.8 MZ 512 Mem
FX 5600 256 mem
BatVink
Moderator
16
Years of Service
User Offline
Joined: 4th Apr 2003
Location: Gods own County, UK
Posted: 10th Jan 2007 10:30
They are definitely springy, and this is an issue I've had many times.

If you increase the weight of your spheres, you will see that they hang down way below the cylinders they are attached to.



Login to post a reply

Server time is: 2019-10-16 20:07:32
Your offset time is: 2019-10-16 20:07:32