View Full Version : EXCELLENT! ACS4 and MB Works sweet together!

07 July 2003, 03:47 PM
I've been playing around with getting acs4 rigs into and out of motionbuilder and I'm very happy to report that they work well together! You can rig with acs4, run the script so it sets itself up and Ik's itself, then export to fbx(don't forget to turn the rig to face -z in layout). Animate in MB, then bring it all back to your scene, where the acs4 rigs continue to perform without hiccups!

The great thing about it is all the control nulls, ik chains and goals that acs4 creates remain intact in MB.

The only problem I see is that if you animated in LW first then bring it into MB, the head of the model freaks out first then straightens out, either from the head control null orienting in the wrong direction or the animation starting further down the timeline for some reason. It looks wacky in MB, but once you bring it back into LW it looks perfectly fine and is as you made it.

07 July 2003, 07:23 PM
oooooh! Thanks for the info.

This way, you do not need to auto characterize and mess with naming and stuff, right? ACS4 makes the rig and everything?

Does the rig that comes out of ACS4 and into Motionbuilder have the markers (the red and blue circles), or do you just manipulate bones? And what does it do with the null shapes (those controller objects that I've seen in screen caps) that ACS4 puts out?

Thanks again :)

07 July 2003, 07:23 PM
well thats cool news, I thought I was going to have to shelf that after I got MB. I really haven't used it yet.

I was assuming the naming would be all out of whack, it also
seemed to have a lot more bones.

will have to go back and play with it again.


07 July 2003, 08:22 PM
I was in contact with Lukasz about creating a Motion Builder ACS4 rig with finger controls via sliders. Although Lukasz has my latest skeleton, I have not received a new version of his rig for testing. He's probably really busy. Anyway this would have been an official ACS4 rig for all ACS4 users.

07 July 2003, 10:00 PM
Well, you still have to manually characterize the skeleton initially. I'm going to try to work on a skeleton that has the MB mandatory bones correctly named. I always assumed that you could only bring in raw rigs into MB, ie simply converting the bones and doing nothing else. I'm surprised at how much stuff you can do to the skeleton in LW (acs4 does a ton of stuff) that can be brought into MB non destructively.

The only thing I've noticed so far is that the .fbx format destroys morphs that were layed previously to exporting to fbx so be sure to save your morph data as a file.

07 July 2003, 03:29 AM
Hi Shade,
Sorry for being so slow to understand, but I am not sure that I understand how ACS4 works with MB. Are you saying that you use ACS4 in Layout to make a rig, then bring it into MB and manually associate the bones in your rig with MB's skeleton?

Also, I thought MB could bring in endomorphs. Is that wrong?
Thanks a bunch!

07 July 2003, 03:44 AM
@Mechis, that's right, use ACS4 to rig your character then bring it into MB and manually associate the bones. MB does bring in endomorphs, but I'm not sure that it recognizes previously animated morphs.

07 July 2003, 03:52 AM
Ah. I see. I'm going to download the ACS4 demo and see how it works out :) Thanks again!

07 July 2003, 04:32 AM
I downloaded the ACS4 demo and I do not think I got the results I'm supposed to. I was able to get the rig created in LW (the rig is pretty cool, btw) and then I exported it to .fbx. When I opened the file up in MB though, I saw the model and there were nulls everywhere. That's not normal, is it? I attached an image of what I saw.

Also, how do the bones match up when you want to associate the bones with MB's bones. Isn't the skeletal structure different?

Thanks a lot!

07 July 2003, 10:01 AM
Yeah, your going to have those nulls in the scene,they are part of how acs4 converts rigs. I think trying to get rid of them will have adverse effect on the rig back in Lightwave. Either hide them (if there is a way) or ignore them, because they don't do anything in motionbuilder.

Michel Besner
07 July 2003, 11:21 AM
In MB, create a group, and then hide it
(Edit Menu -> Groups ....)


07 July 2003, 05:53 PM
right on, thanks!

07 July 2003, 08:53 PM
I don't get it, for biped characters, why would u still need acs4 if you are using mb. I feel way easier to animate in MB than in LW.

07 July 2003, 04:37 AM
ACS4 makes rigging easier and much more reusable. I think you also assume that you will always be able to completely finish what you are doing in MB, which will not always be the case.

07 July 2003, 06:26 AM
With much experimentation, I was able to get the ACS4 rig into MB and characterize it. I have a couple of questions and was hoping you might be able to help me:

1) To use the setup, did you make an fk/ik control rig? I found that I could not manipulate the setup, unless I did so.

2) I did not seem to have the control that the ACS4 rig has in LW. For example, I could not lift up the heel, while keeping the front of the foot on the ground (like rotating on the ball of the foot) and I could not rotate the forearm from the elbow (like I can in the MB standard rig).

Maybe I am making mistakes that I do not know? Maybe it is how I characterized the rig? For the most part, the rig moves fine, but I am not sure if the ACS4 rig offers mobility/control advantages that the MB standard rig offers already.

If you get a chance, please tell me your thoughts. Thank you!

07 July 2003, 05:30 AM
just caught an old thread about the experimental features in LW, double the speed of ACS4 in LW.

worth a try

07 July 2003, 04:10 AM
that experimental thing didnt' do jack for me, and it gave me poppy ik solving.

I don't see how you can import animation from MB to lw and then use ACS for cleanups. The whole ACS rig is very much Goal and expression driven, which will override your animation data in the bones. Wouldn't that be pointless to use ACS after MB? One of the reasons I purchase MB is not have to deal with LW as much in the rigging and animation process. It feels to me a waste of time rigging your character everytime you throw that into a package and exporting out to another one.

07 July 2003, 08:41 AM
This is great news indeed. I am sure lots of us bought ACS4, and I thought I had to waste my copy of ACS4 since MB comes out. It'd be great to have both work together.

solar power
07 July 2003, 06:07 PM
uhh.. Basic one here but,

I'm missing something when I put my ACS rigs into MB. I can go ahead and charachterize and animate, but all my goals and nulls don't move at all either in MB or LW.

The characters mesh looks fine in MB, the goal/nulls stay at 0,0,0. But obviously when I get my model back into LW, the skeleton animates fine, but (of course) since the goals/nulls dont move there is stupid serious mesh deformation going on.

What part of the process did I miss?

Using ACS3 Rig, but I don't think that has anything to do with it.

Thanks for any ideas. Here are the bone assignments that I've used.

07 July 2003, 08:04 PM
The ACS3 and 4 rigs are very different from each other. Could be any number of things.

solar power
07 July 2003, 07:13 AM
As far as charachterizing in MB. You use the actual bones from the ACS Rig right? Not the joints or goals.

Can you elaborate on the steps you take to charachterize your ACS4 Rigs in MB? Do the assignments that I've made look correct to you?

Are you able to animate multiple ACS Rigs in MB at the same time?

tnx for the 411.

solar power
07 July 2003, 05:26 PM
OK. Maybe we all can work together to get a nice comprehensive list of steps in the LW+ACS+MOTIONBUILDER pipeline in one place. Seems that others have had trouble finding the way also, so it would be nice to share the smarts. This has been my process. It must be fundamentally flawed because I cant keep all the pieces of the Rig together throughout the journey. Using both ACS3 & ACS4 rigs I still end up with animation on the skeleton, but not on the nulls and other control stuff in the ACS Rig.

So, maybe those of you who are rockin' with mad ACS style can edit this list to include what I'm missing, point out my mistakes, and include any other wisdom you've gained along the way.

Thanks for sharing the knowledge.





1. Export ACS Rig from LightWave as .fbx using Kaydaras plugin. ( )

2. In MB: Open Rig.fbx Drag a 'character' from the Asset Browser (Templates>Characters>Character) onto the mesh. The mesh should turn green as this happens. Click "Characterize".

3. Manually associate the parts of the ACS skeleton with the MB naming conventions in the "Character Defintions" tab. "Reference" and "base" are required. Do this either by atl+dragging selections from the schematic view into the 'model' fields of the "Character Defintions" tab, *or* by dragging elements from the scene browser.

4. Click "Characterize". Answer 'yes' that your model in LightWave was facing -Z before you exported to .fbx.

5. Click "Create Control Rig" in "Character Defintions" tab.

6. Animate

7. "Plot the Charachter" to the skeleton. (Character Controls Panel >Edit > Plot Character)

8. "Save File as.." from MB. Give the File a new name. (Do you choose "just animation"?? no lights, no camera, devices??? dunno)

8. With original ACS Rig open in LW Layout > use the Merge FBX plugin. Animation should now be in LW. ( This is where my Rig gets all messed up. The skeleton moves, but all the nulls stay in the same place.)

These are the associations that I've been making in MB. But I'm still having problems getting my Rigs to behave.



Hips ===============Root
RightFoot ===========R_Foot

What parts of the ACS Rig are supposed to move while animating in MB. Seems that most of my nulls don't move while in MB, but the mesh looks alright untill I get it back into LW.

07 July 2003, 08:16 PM
Yeah. I was trying to do this too after I saw this thread (I posted in here earlier). I got as far as you did. I never tried to bring the rig back into LW, because I wasn't sure that the ACS4 rig really had any value that the Motionbuilder rig did not have (control-wise).

I'm not sure, but I think the only reason to even try to use the ACS4 rig is if you want to animate a little in MB and a little in LW. I decided that I was just going to try to do all my animation in MB and not animate at all in LW.

Feel free to correct me or tell me I'm wrong :) What do you all think?

solar power
07 July 2003, 04:29 PM
OK, to sort out the problems I'm having in LW with my ACS Rigs, I went ahead and set up a Rig using the famous 3DDave skeleton.

And the same problem is occuring with the 3DDave Rig. After merging the animation from MB into the LW scene, all that is translated is the skeleton. The Reference_Null and the bounding box that represents the mesh remain at 0,0,0. Usually the bounding box will follow an animated object.

Now, using the 3DDave Rig yields much more pleasing results because the mesh sticks to the skelly and the limbs don't point at any goals (whereas the ACS Rigs get all screwed up because the IK goals remain at 0),

but are these the results that others are getting in LW also??

I really would like to be able to set up charachters that could be animated in MB as well as in LW. The ACS rigs are very powerful in certain situations. But, obviously, MB is much better suited to certain types of animation. It would be nice to be able to use the same rig, although I guess I could take the time to build two separate Rigs for each character.

Anyone have experience they'd like to share?

Shade said: "Animate in MB, then bring it all back to your scene, where the acs4 rigs continue to perform without hiccups!
The great thing about it is all the control nulls, ik chains and goals that acs4 creates remain intact in MB."

I haven't been able to bring this functionality back to LW. Real interested to hear how its done.

solar power
07 July 2003, 04:08 PM
Alas. Despite many attemps, research, and networking, I have yet to be able to move a functioning IK/FK ACS Rig into and out of MOTIONBUILDER.

(anyone is welcome to chime in here and expose the error of my ways.)

But in my travels, I have established an acceptable work around for anyone who might want to convert ACS Rigs (or any IK/FK Rig) to function with MB.

TIP: If you do the renaming of your charachters Rigs (prefix or suffix) in LW first (i.e. using the ACS skeleton)..... you'll have to manually charachterize in MB, but you'll then be able to import animation in Scenes with multiple charachters from MB to LW without having to do the lengthy saving of animation on each character

(Select branch -> Save Selection ->Merge animation to charachter_1 in its own LW Scene ->Repeat for character_2 ->then merge the two LW Scenes using 'Load From Scene')

because none of the charachters Rigs will contain the same name, there won't be any problem mapping animation to multiple charachters. Plus you won't have to re-assign the weightmap relationships to the renamed bones.

Too bad MB doesn't support a dot separator in the bone naming convention (Char1.Hip, Char1.LeftUpLeg, etc.)

Ok. So basically in LW I just stripped all the IK features of the ACS RIG. When the goals and target items are removed, all the bone's motion properties revert to 'KeyFrames' instead of 'IK'. This leaves you with a basic skeleton, the mesh, and the main 'reference' null. All of the 'parenting' and 'weight map to bone associations' remain intact.

Anyway. If I was me a few days ago (which I was, by the way=) I would have like to have been able to read this. Hope it helps someone.

Here is the ACS -> MB bone mapping structure that seems to work well:

CGTalk Moderation
01 January 2006, 03:00 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.