PDA

View Full Version : Problems with parenting



Billybopper1
03-03-2010, 09:58 AM
Does anybody know why objects behave strange when you parent them? I'm trying to animate pages in a book. Each part of the book is on a separate layer and each layer is parented to a null I've created for the book. But when I want to parent a page to the cover of the book and I try to move or rotate the cover, the page starts flying off into another direction. Why does this happen?

4dartist
03-03-2010, 10:09 AM
Hum.. It's hard to tell without being able to look over your shoulder and see how you have things parented and where the pivot points/origin for everything. Do you understand the difference between parenting with 'parent in place' on and off? This is very key to setting up relationships. If you parent your page to the cover, and the page is already in the exact spot you want it to be after you parent, then turn parent in place on.
Basically what will happen, is once you parent, lightwave will make the page a child of the cover, but it will force the page to stay exactly where it is at that keyframe. (to do this it will create keys in position on the current frame)

My suggestion is to make all your parenting changes at frame 0. If you do it at frame 30 say, keys will be created at frame 30 so the page is right where it was when you did the parent. Then if you slide back to frame 0, you may have had keys there where the page was when it was unparented, but now that it's in the xyz local space of it's parent, that may be off in 'who knows where'.


Edit: I'll just make a note on how parenting with 'parent in place' off works. First you need to understand that every layer of your object file, null object, light, camera, etc all have their own local coordinate space. 0,0,0 for each of them is at their origin, basically where ever 0,0,0 was in your model file, or exactly on the light or camera. So if you have an object placed at 0,0,0 in xyz, and you make it a child of a null that is way up in the sky, your object will retain it's position of 0,0,0 but in the new coordinate space of this null in the sky, thus your object will warp up to the sky right on top of the null. 'parent in place' on would keep your object exactly where it is, but create keys in the new coordinate space of the null in the sky. Now instead of xyz being 0,0,0 it may be something like 0,-50,-20 because it's way lower then the null.


I hope this helps some, feel free to ask questions or upload a scene file. I can help determine what problem you are having.

Billybopper1
03-03-2010, 10:39 AM
Thanks! I'll try that. By the way, how do you turn on the "parent in place" feature?

4dartist
03-03-2010, 11:06 AM
It's in the upper left in the menu. I think I have the default menus so it should be there unless you changed them. A good way to find things is to use the hotkey editor.

1st thing I would do is set the hotkey editor to the hotkey F1. Then everytime you need to find something or arrange keys, boom, hit F1, click search, type in 'parent'. It probably will find something else, but then just keep hitting search/enter and it'll pop up. It'll come up on the 7th try or so. I have parent in place assigned to alt-a or option-a. I use it constantly.

ALso, it's a toggle on or off, so however you have it set it'll stay there until you tell it otherwise.

Billybopper1
03-03-2010, 08:31 PM
I'm sorry, I still can't find it. :cry:Perhaps if you post a screenshot?

4dartist
03-04-2010, 08:35 AM
Make sure you are looking in Layout, not Modeler. :) This toggle effects objects when you are parenting in the scene editors of Layout. Modeler has a way of setting up a child/parent relationships, but basically they all get parented at their origins by default there.

Here is an image of my Layout and the Parent in Place button.

Billybopper1
03-04-2010, 10:28 AM
Is "parent in place" a recent feature in Lightwave because I don't seem to have it. I'm using 8.5 version. I also incorporated 3D arsenal.

4dartist
03-04-2010, 10:55 AM
Yes it's in 8.5

Do some searches in the hotkey editor. Search a bunch of times for 'parent' 'place' 'parent in place'

If you still can't find it.. then maybe someone with 8.5 can help you locate it.

I have 8.5 at home I think, I may be able to look later.

Ben

Billybopper1
03-04-2010, 07:34 PM
Where's the hotkey editor?

RebelHill
03-05-2010, 06:20 AM
its also in ur general options panel.

Billybopper1
03-05-2010, 11:22 AM
I must be missing something. I have Lightwave 8.5 via my VT4 and neither button is there.:question:

Billybopper1
03-05-2010, 09:50 PM
My version of Lightwave 8.5 has a layout menu configured to 3D Arsenal. How do I add the "parent in place" button to the general menu?:help:

THREEL
03-09-2010, 07:05 AM
Also, once you get your parenting problems figured out, make sure you have the Subdivision Order set to Last on all of your Objects. You'll find this button in the Object Properties dialogue box.