> Organization: GXSN
> Newsgroups: comp.graphics.apps.lightwave
> Date: Sun, 6 Aug 2000 15:01:44 +0100
> Subject: Please,please,please help, with sugar on top
> I've posted the following several times without a response. If what I'm
> trying to do, can't be done, i'd be very grateful if someone experienced
> could point me in the right direction. Thanks,
> 'I usually find some geometric logic to enable two objects to align.
> However, my current model requires several identical objects to be aligned
> at an arbitary rotation. Is there some simple way to align objects in a
> manner that can be achieved with CAD programmes such as AutoCAD? Basically
> I want one poly to rotate and position itself to another.
> Can anybody help?
> Thanks in advance'
Center all objects in modeler and place them in the proper orientation for
animation. In otherwords..if the "cone" will be orbiting "standing up"
then..make sure its already "standing up" in modeler..ie..before you bring
it into layout.
set pivot points in modeler so that the objects will rotate as needed
ie...in otherwords..the rotate axis...if you want smooth rotation around the
middle..or..do you want it end over end..ie..move pivot point to one edge of
object or the other...etc.
After saving the objects...import ALL of them into layout without moving
Create a null
parent all objects to the null.
Move all objects into the location and starting position you want.
At this point..you can now rotate the null..and all objects will move around
the null in the same relationship to each other.
If you also need the objects to rotate individually...then..adjust the
rotation of all objects a key 0 to have the desired offset you want.
Move forward to the time interval that you want for one complete rotation..
and key frame each object for 360 degrees from its original starting
point...(you could also use an lscript or something else..that would simply
apply an offset for each object.) Key frame it..and set the end frame to
Alternatively..you could apply the offset in modeler before you bring them
in...and..simply save one motion (thats a 360 rotation) and apply it to all
What you should now have is...a starting frame with the offset already
applied...and..when you play it...each object should rotate together
at the same rate..with the same offset throughout.
Now you can key your null...and move the whole thing...like a merry go
This way you can have..control over the rotational axis of the whole
thing..And...control over the rotational aspect of each individual piece.
If you plan on having them rotate at always the same rate..then..
using the key at 0 with offset ..then..key at end..with 360 rotation on all
objects works fine.
The issues here are...you have to set up your objects correctly from the
start. If you have a cone..and want it to rotate in an oblique fashion..you
should set it up..in modeler thru the pivot point..and..make sure its at the
right rotational axis when you bring it in. Otherwise...youll be
applying..and keying several rotational channels to get the disired effect
and may end up running into our friend ...Mr. Gimbal Lock.
In other words...don't load a cone object.."standing up"..if you intend on
rotating it.."lying down". Because..it keeps its rotational axis channels
as they were set in modeler. ie..if you did the above..you would be rotating
its "pitch" to get it to rotate around..lying down. So, if this..for
instance was the case..I would go ahead..in modeler..and..rotate the
object.."lying down"..so I could now use..the proper.."heading" channel to
Same issue for pivot points...center all your objects...then..move the pivot
point..to where you want the rotation to apply. If you want it to tumble
"end over end" then youll need a pivot point..at one end or the
other..instead of in the middle.
All of these things prevent..or try to prevent problems in parenting to the
If you don't wont' the objects to move at the same rate..then..it will
require a little more work keying the objects to each other. In this
case..use ONE object..to start...and key it...then..use its key the others
against it. ie...I want this one to rotate 2x for every 1x this one goes
around..etc. Once you get one "cycle" done..then..just set it to loop
animation. or repeat motion.