XM Magdalena 3D print, GGeorgy (3D)
LC #42 Pipers Alley

View Full Version : Rigid Body scaling

04-01-2008, 12:45 PM
I have a few pin contraints set up to form a sort of chain or ropey effect that make up the chain or chord of a hanging lamp. the lamp is supposed to be swaying back and forth. Now whe i have the sphere rigid bodies setup with the pin constraint it works fine. but once i ad the spotlight to it it gets all strange.

I have experimented and concluded it is b/c of the physical shape of the spotlight in the scene. when scaled down i get normal and decent results. however i have fog display on the light so scaling down the length it shows doesnt help much since im not getting the result i want.

ANy suggestions?

04-01-2008, 05:44 PM
1 view all day? haha, am i being shunned?

04-01-2008, 06:56 PM
1 view all day? haha, am i being shunned?

Probably nobody has been online since you posted more like :)

Its hard to say what your problem is because to say "it gets all strange" doesnt really explain anything sorry. Obviously you cant add a spotlight to a rigid body constraint cause it aint a rigid body but you already know that one Im sure. You most likely want to parent the light to the rigid body.

04-01-2008, 09:51 PM
oh i thought i cancelled that post before it sent! sorry it was just a silly response. Basically once the light is parented to the rigid body the simulation becomes more erratic with random position and rotation shifts that normally wouldnt follow the typical simulation.

04-01-2008, 10:30 PM
mmmm not sure as to why, you could try zeroing out the rigid bodies transformations before you make them rigid bodies which would mean setting up your scene again sorry. I just tried it myself and it works fine my end, can you upload the file? Or it may just be the order you did things in may not work so well.

04-02-2008, 01:45 AM
sure thing Aikiman. Here's a previous version using a Pin Constraint and Nail constraint to get some spin. I'm actually ok with the overall effect but i kind of wanted the lamp to have a little more subtle jerky-ness when it fell in.

I originally wanted the lamp to fall in upside down from up by the sphere on a rope like structure so it would flip over with a nice simulation. but i am out of ideas on how to simulate that.

Scene should be attached to this post

04-02-2008, 02:24 AM
okay, 2 things will help with shakiness, one you have already touched on already and may still need increasing and that is the dampening for the rigid body (lamp shade). Also try increasing the mass to 100 and see if you like the effect. The size of the light will have absolutely no effect on the dynamic simulation because it has no mass to calculate.

To achieve the cord effect you would need to move into softbodies with goals and springs and parenting cluster handles to your rigids. I found this tut through google...
http://www.dezfx.com/HTML_pages/TutorialPages/dynamicRope.html just replace the locators with your rigids.

[Edit] instead of using the cylinder you can use a curve so that you can curl and twist it up as you draw it. Afterwards you extrude a circle along the curve to create your cord.

Good Luck!

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04-02-2008, 02:24 AM
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