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lreyes
09-04-2010, 03:22 AM
What is the best way to position child joints in a mesh. I find it hard to move those joints to fit a leg or arm. Do I have to make a null and assign that null to the mesh, but I still have to move the joints to fit a leg or arm.

Cohen
09-04-2010, 05:52 AM
Best way 'now a days' is to just do it right there in Layout. You can, of course, make your 'skelegons' in modeler and convert them to bones in Layout if you wish. If you are rigging a character, hit 'F4' a few times until you get 3 or 4 orthographic viewports (left,right,top, for rigging). Then add 'joint' tool and position it at the base of your character, where you want its COG to be (Center of gravity / Center of Mass). Then simply choose 'draw child joints' and click, click, click. ;)

BTW, I highly recommend using the new joints and not the old z-bones.

Cohen
09-04-2010, 06:09 AM
oh, and a few more things for clarification: Lightwave now offers two different types of bones. The old Z-bones system, and the new joints system (I dont know if you already knew this, but its worth mentioning). Anyways, the new joints are incredibly easier to work with.

Don't use any of the 'bone' tools, just stick with using all of the 'joint' tools. When positioning a joint with the new system, the joint will move indepent of its neighboring joints. Where as with the old bones system, you would have to use a special tool to move individual joints without affecting neighboring 'joints' (Ctrl+J Joint move tool).

If the joints appear too big or small, hit 'd' for preferences, and choose 'display' tab, then under the 'handles & Icons' tab you may adjust the size of which the joints appear in opengl.

good luck o/

RebelHill
09-04-2010, 06:10 AM
Huh... what?? Just position them where you want them. Best done by rotating a parent joint rather than translating a child to make sure your joint axis alignment is correct.

So select, rotate to orient, position child at distance in Z.

lreyes
09-04-2010, 10:10 PM
Thanks for the help. but once you put the joints down, how do you move them to get them exactly where you want them, I could not find a way to move the joints, unless I am missing a vidal step.

The Scientist
09-05-2010, 12:01 AM
Thanks for the help. but once you put the joints down, how do you move them to get them exactly where you want them, I could not find a way to move the joints, unless I am missing a vidal step.

I'm not exactly sure of your question but I'll try to assist.

Make sure that you select the joint itself and not the deformer (the circle, not the z-bone shape).

Hope that helps.

Cohen
09-05-2010, 06:35 AM
Thanks for the help. but once you put the joints down, how do you move them to get them exactly where you want them, I could not find a way to move the joints, unless I am missing a vidal step.

To move a joint? Just select one and move it. >> Press 'shift+B' to enter bone selection mode. Then left click on a joint to select it. Then 'T' to activate the move tool, and move your joint to the desired location.

Hope this all helps.

Cohen
09-05-2010, 06:48 AM
I find it hard to move those joints to fit a leg or arm.

Quick tip:: make sure you activate 'bone X-ray' mode in the viewport, so you can see your bones through your mesh.

Quick tip:: lock your item in the scene editor, so that you do not mistakingly select it when selecting bones.

Greenlaw
10-25-2010, 12:21 AM
Hi,

Quick question: Is there a way to do something like Bone Tools Joint Move with joints yet?

If not, maybe we need a modifier key to allow this. Should this be fogbugz-ed as a feature request?

G.

EDIT: I should clarify the above. I know that technically Joint Move is supposed to work with joints but, in my limited experience, this only works in a very limited way. To me, it appears that if you translate your joints outside of Bone Tools, this completely throws off tools like Joint Move; Joint move seems to always think the joints are at the rest length of z-bones, not where the joint objects actually are. Or something like that. Can somebody confirm this for me, or explain what's going on with the tool? Thanks in advance for any info.

The Scientist
10-29-2010, 10:13 AM
I've tried using BT Joint Move on joints before but I wasn't getting desirable results. It's a work around but if you change the parent for the descendant of the joint you'd like to move, you can translate that joint (not BT Joint Move, just translating) without effecting the rest of the hierarchy. Another idea is to change the Bone Type to Z-Axis bones, use BT Joint Move, then change the Bone Type back to Joints.

Hope this helps

Castius
10-29-2010, 10:54 AM
Joint orientation matters!

Do not just move joints to place them. Yes the bone tools in layout do not work great with Joints. But it's still better to use them. Or use skelegons.

Greenlaw
10-29-2010, 11:56 PM
@Scientist: Thanks! I think the unparenting trick will work for me. My findings so far is that Bone Tools is not very friendly when rigging for a motion capture session, so any tricks that allow me to do similar things without BT is very helpful at the moment.


Joint orientation matters!

Do not just move joints to place them. Yes the bone tools in layout do not work great with Joints. But it's still better to use them. Or use skelegons.

Thanks to both of you for your information. You've given me some more food for thought. :)

Here's what else I've learned since posting my question:

I initially used skelegons for placement, but it eventually becomes unavoidable to move the joints in Layout to improve deformations. According Rebel Hill's excellent LW FBX to Mocap videos (http://rebelhill.net/html/lwandfbx.html), moving the Joints in Layout is fine so long as you don't rotate them. Unlike with z-bones, translation does not affect Joint rotation. On the other hand, rotating the Joints or using Rest Rotations apparently causes Motion Builder to flip out, and I'm finding that this is true for Animeeple too.

FYI, I recently used D-Storm's Load Bones plug-in (http://www.dstorm.co.jp/dsproducts/lw9/FreePlugins/Bone_Skelegon/Load_Bones.html) to get a positioned Joints rig back into Modeler as Skelegons. This was a fast way for me to reset my Joint rotations to true zero, which is necessary when creating motion capture rigs. (I had previously screwed things up using Rest Rotations and other silly things.) Here are some tips about the process:

* The plug-in was desiged for Lightwave 9.3, which means it doesn't fully support Joints. However, you can use the plug-in in Modeler 9.6 if you save out your scene file in Lightwave 9.3 format, which you can do in any recent version of Layout. (In other words, you do not need to use LW 9.3 for this.) You can then load this version of the scene into Modeler 9.6 using Load Bones. (One more tip: this seems to work with Modeler 9.6.1 too.)

* Technically, the plug-in is not compatible with Joints. However, if you delete all the Skelegon tips in Modeler, the remaining base points will be accurate for Joints. Just connect the base points using curves and convert the result to Skelegons. You should, of course, set the desired rotations in Modeler after conversion.

* In Modeler you only need to do the center Skelegon bones and one side of the rig. When you convert the Skelegons to Joint Bones in Layout, use Bone Tools Mirror Hierarchy to complete the rig. Mirror Hierarchy is one Bone Tool that does work well for motion capture setups. :)

G.

Greenlaw
10-30-2010, 12:23 AM
As I typed all that, it occured to me that for a mocap rig it might not have been necessary for me to go back into Modeler to fully zero out the Joint rotations. Oh, well...there you go anyway.

The rules for rigging for mocap still seem so weird to me. :)

G.

The Scientist
11-04-2010, 04:46 PM
I've done plenty of mocap rigs before so I know what you mean about weird results. Like you said, recording pivot rotation will mess you up. So I use only skelegons when rigging for mocap, then convert them to z-bones or joints in Layout (if converting to joints, making sure to add an "end" skelegon to the tips of each hierarchy).

Of course accidents happen all the time, in this instance accidentally recording pivot rotation, so one tool that might be a saving grace in the rigging for mocap proccess is "Remove RPR" (Setup>Modify>Orientation>Remove RPR). This tool will remove the offset given to a bone (or joint) when record pivot rotation is used, and it's come in pretty handy for me in the past.

But if you're using skelegons from the start you have the awesome possibility to simply reconvert your skelegons into your mesh (after clearing out the previously converted skelegons of course) and being more careful to not record pivot rotation the next time around.

These methods have worked for me in the past multiple times, I hope they help you out as well.

-Kurt

Greenlaw
11-04-2010, 04:54 PM
Thanks Kurt. I'll keep these tips in mind.

G.

Castius
11-04-2010, 06:23 PM
You could also use Dodgy's or my scripts for repositioning skelegons in layout.
http://www.steelronin.com/plugins.htm
http://www.mikegreen.name/
Update bones

I don't know how Mine and Dodgy's script will work on joints. But i suspect they will work.