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assistant pimp
08-19-2005, 03:34 AM
Ok, I couldnt find any good stuff on rigging and animating mechanical stuff so I am trying to go it alone. But I have quickly reached a hurdle. I am starting off with real simple representations of what I am trying to do see below. This first image is what is happening when I am trying to simulate a robotic joint.

http://img372.imageshack.us/img372/402/bonemistake8wx.th.jpg (http://img372.imageshack.us/my.php?image=bonemistake8wx.jpg)


This is what I am trying to achieve.

http://img372.imageshack.us/img372/9887/bonecorrect6ae.th.jpg (http://img372.imageshack.us/my.php?image=bonecorrect6ae.jpg)

I can understand why LW is doing this. But I cannot understand how to prevent it. Please give me a lil push over the top to understanding this. I figure I would try LW before buying maestro or something like that.

Xristot
08-19-2005, 05:15 AM
are they on the same layer and are you using bones? if so, then try making the weights absolute so that you only move the pieces that you want each bone to represent...

if they are on a different layer you can try to just use parenting, nulls and targets to get it right.

ericsmith
08-19-2005, 05:16 AM
There's two easy ways to fix this.

1. Make a 100% weight map for each part. Then, apply the appropriate weight map to the bone that is tied to that part.

2. Don't use bones. Put each part on it's own layer, and position the pivot point where the part should rotate. The, bring the parts into layout and parent the parts into a hierarchy. You can then either rotate each part to animate, or you can set up IK on the hierarchy. You don't need bones to use IK.

Eric

Carm3D
08-19-2005, 05:40 AM
Yes, the best way is not to use bones at all. Put each moving part in a new layer and place it's pivot point in the appropriate place on each layer. Bones that deform the geometry is MUCH slower than just moving objects around.

proton
08-19-2005, 01:08 PM
Check out the Tutorial that is in the LightWave 8 help file :

Tutorial - Pivot Points

Pivot Points play a large role in animation. A Pivot Point is the position in an object that acts as the center of rotation and position reference. This tutorial should help explain how to work with pivot points in your animation. Let's get started.




This should get you everything you need to do this kind of setup.

Good Luck!

assistant pimp
08-19-2005, 01:58 PM
aaahh.....ok. I was under the wrong impression. I thought bones was the way to go because the movement of one object influences the movement of the other object. Kinda like a hydralic piston being used to extend an object. I will definately look into the help files. believe it or not I normally look there or the manual before posting. But I kept looking for "bones" this time around in the help files. I appreciate the help.

Going to give it another go today. Thanks ya'll

doc sampson
08-20-2005, 05:31 PM
Linking things in a parent/child hierarchy does that. This works the same for bones or objects. Bones have the added ability to deform geometry automatically but this has nothing to do with one object influencing another :)

T4D
08-21-2005, 05:11 AM
setting up your pivot points and layers in modeler And setup your parent/child hierarchy in layout with Parent in place ON is the way to go for mechanical stuff IMO

You can uses bones and weight map only option but that does make a simple job complex
remember K,I,S,S in any 3D program and things will be easier:thumbsup:

jabbermike
08-21-2005, 07:59 AM
For starters I recommend to build each object so that the pivot is on 0,0,0 im Modeler. Although there is that tool to move the Pivot in Modeler, some tools and porcedures in Layout do not recognize the moved Pivot. So you might run into some weirdness then.

mike

T4D
08-21-2005, 08:34 AM
once you load the object in Layout the pivot points are set for the scene

So it's best to set all your pivot points for each layer in modeler correctly First, before you load into layout, then uses parent in place ON and reparent as needed

Then You won't have to modeler everthing around 0,0,0

assistant pimp
08-21-2005, 04:00 PM
thank you again guys....I am still having a few issues with making like a piston (stabilizer)work correctly between 2 moving parts connected by a joint. Gonna keep chugging for now tho.

jabbermike
08-21-2005, 04:42 PM
once you load the object in Layout the pivot points are set for the scene

So it's best to set all your pivot points for each layer in modeler correctly First, before you load into layout, then uses parent in place ON and reparent as needed

Then You won't have to modeler everthing around 0,0,0

You are quite right about that. But if you have to add additional (null)objects to the scene and want to align them to that object, there is one thing that doesnīt work. Itīs when you have a pivot point that was repositioned in modeler, itīs not posible to parent an other object or nulls to that pivot point, so that the child jumps to the "new" pivot point. So in such a case, which way to go depends on whatīs more work: to rearange the hirarchy of the one object or to rearange the parents/child setup of the added objects.

If Iīm wrong about that I would appreciate if someone could help me out of this.

mike

T4D
08-22-2005, 12:58 AM
if you want a null where a object is, clone it, then use replace with Null object.

jabbermike
08-22-2005, 07:07 AM
:applause: Too simple! Thank you very much!

mike

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