So i’m knee deep in making a Starship troopers aracnid esque type character. I solved the control rig issues by using a quadruped character type and using the following joint hierarchys for the front/back legs:  Arm/ForeArm/Hand/Fingerbase UpLeg/Leg/Foot/Toebasebase So basicly the character is walking on its toe/fingerbases. The character also only has one spine node since motionbuilder requires you to have one and finally a head node. So basicly the minimal amount of bones you need for motionbuilder to accept the hierarchy which it does.

The controlrig and animation works just fine but the problems start when trying to get a ragdoll working on this rather unconventional character. I can add the ragdoll and set up the body parts which required alot of work since the standard setup didn’t really work for the character. I then add a solver to try the ragdoll and press online and the live button in the physics solver. Nothing happens. The bodyparts don’t simulate at all.

I tried exactly the same workflow with a regular character and that works. Does anyone know if thare are any limitations as to what bones/options a character has to have for the ragdoll solver to work properly? 

I’m using motionbuilder 2010 btw and i am exporting from maya.

/Mikael Hansson

Mikael Hansson
Lead Animator
Fatshark AB

“Games are like sausages, the end result may be tasty but you don’t want to know what goes into them.”

So i found a solution myself by using the nifty search function but it still didn’t work. According to the previous post i need to have collar bones on the character for the ragdoll solver to work properly. I tried this by changing the bone hierarchy of the front “legs” to incorporate the shoulder bone Shoulder/Arm/ForeArm/Hand so that the character now walks on its hands as opposed to walking on its fingerbases. Still no action when starting the physics solver and making it live though. Can anyone confirm if the collar bone problem has been fixed or not in mb2010?

Mikael Hansson
Lead Animator
Fatshark AB

“Games are like sausages, the end result may be tasty but you don’t want to know what goes into them.”

By default the ragdoll has limits set to a more human like range of motion, if your adding it to a quad character the limits are not going to allow for the simulation to move the ragdoll as you expect.

Look at the limits for the ragdoll and see if that helps.

Brad

Brad Clark
Co-Founder: Rigging Dojo-Teaching the art and science of character rigging
Author: Inspired 3D Advanced Rigging
The Character Animator Toolkit for Motionbuilder :available now: