Ridgid joint modifier and armatures parenting

hi all,
its been a while since ive been trying to make my character s long coat look like a real cloth,but what i realized is that when u parent the mesh to the armature it obviously creates vertex groups which prevents the ridig joint modifier to work,only when i remove the vertex groups the coat acts as a cloth,by that i end up with the conclusion that rigid joints dont work with armatures thus i cant achieve my goal to make it look like a cloth,i tried a script but the same issue occurs as soon as i parent to the armature…can anyone enlighten me with ideas?
thanks in advance,

I don’t know anything about soft bodies, but you can get a decent cloak with a partial ragdoll component, no python required (with 2.5 at least) :D.

-Parent some static collision shapes to the armature bones for the chest, arms, legs etc.
-Then make the cloak shape with say about 2x4 panels (rigid bodies, connected to each other and the chest collision shape with the appropriate rigid body joints)
-Add copy loc/rot constraints to the armature bones for each of the cloak panels
-Add the armature actuator to run the constraints

Results should be similar to the skirt, cloak and hair in these video’s, no complete ragdolls required


im a bit confused but not enterily,is it possible for u to make a mini tutorial? if so i really appeciate it and thanks for the first reply ,bout the videos i can tell this is the best solution for me…it would be really cool a mini tutorial!
thanks in advance,

Just follow the 4 steps in the first post & I made a simple example .blend, maybe I’ll put it in the resources. I doubt it is a technique most people consider as an alternative for soft bodies for cloth etc. :D; this seems to keep a decent framerate.

PS: I know it is a crappy example animation, I am not much of an animator so I prefer to let ragdolls sort it out :stuck_out_tongue:


SoftBodyAlternative.blend (828 KB)

Np dude i really appreciate ur help and for having ur time dedicated to my thread,ill download it and then will try to apply the tecnique into my file…
so thanks a lot so far and ill be back later

hi bro,
i tried exactly the way u did but something went wrong unfortunately so im sending u the file so u can analyse what i am missing …thanks in advance!

File : http://www.megaupload.com/?d=GELIEO37

Your collision box interferes with the cloak collision objects. Objects either need to not overlap, be Rigid Body Jointed together or be ghosts to avoid that.

Waiting for the horribly slow download… (www.pasteall.org/blend is much more user friendly ;))

Some more pointers:
-The DynamicBox is indeed interfering, make it very flat just above the floor and it won’t get in the way of collisions
-Add collision shapes to all the individual leg bones, deforming mesh does not update bounds (so set the deforming mesh to no collision also to avoid it from interfering)
-Then add the bones you want to make up the cloak (I think my knight skirts are the best example to look at, maybe close it on the backside with some extra panels/bones)
-Add panels for each cloak bone to follow, make sure each panel local axes are aligned with the local bone axes (bone length is in Y direction)
-There is no fixed number of bones/panels to animate the cloak; it is a trade-off between accuracy and performance
-Add rigid body joints to connect the panels together, make sure always one of the pivot points corresponds to the bone pivot point position
-Add the bone “copy rotation” constraints for each corresponding panel, if the pivots of the rigid body joints are at the right position then copy location can best be left out.
-Add the armature actuator to run the constraints at runtime

this is too much for my tinny brain a video tutorial would be the best way,its quick and easy to record it,but ill keep trying…thanks a lot for now and having ur time…and here it is the file:

thanks in advance,

i ll be waiting for the fix and for u to point me out where i missed the point

Have you tried re-making my example for yourself? Just play around with something simple; 2 or 3 objects connected with rigid body joints and then try to get the bone constraints (copy rot/loc) working.

It is good to figure out the basics before applying it to something complex, and you’re not going to learn if I build everything for you :wink:

Hi dude,
yeah i know u have to teach the student how to fish and not fish it for him lol,but i dont even know where to start when u say: try to get the bone constraints (copy rot/loc) working,for me u speaking in greek( sorry greeks thats an expression here in Brasil so dont take it personally ,its just another way of saying u speaking a different language) dat been said,in my file i couldnt even get the box plakes to deform my mesh,they move independently nd dont deform the cloak…ill try to play around with that but it would be cool if meanwhile u fix that for me then i would have more homework hehe…i promise u ill play aroudn with simpler mesh,i love to learn things but in this case its been over a month im trying to figure out how to get it to work and till now nothing ,i only got failures which kind of demotivates me…
anyways ill keep trying but im almost 100% sure i wont get it to work in my file!
thanks again.

Ah that helps to clear some issues :slight_smile:

some quick pointers

Collision bounds
-See properties menu => Physics
-Check the collision bounds checkbox for better collision shapes, it is most efficient to use one of the primitive bounds before convex hull
-The cloak panels work best work the ‘box’ shape
-Limbs like legs can propably best use ‘capsule’, in which case the limbs need be aligned in z-axis

Rigid body joints
-See the properties menu under constraints
-Then add a rigid body joint for the cloak panels, connect them to each other and to the chest (or whatever part the cloak is attached to the character)
-move the pivot points around to the start of each bone or between panels (see example file)

Armature constraints in short
-To put bone constraints on the armature you have to select the armature and go into pose mode
-Then in the properties menu look for Bone constraints
-Add constraint, then select copy rotation (or copy location), after that you can select the target (in this case the corresponding cloak panel object)
-To run the constraints in-game add an armature actuator in the logic menu, set it to “run armature”

Those are the relevant menu’s I used so if it is not clear you can check how it is set-up in the example .blend.

The rest is just tedious work setting all up and getting the bones and cloak panels to align properly…

If it is still not clear you might better start off with some more general blender tutorials

Armature constraints in short
-To put bone constraints on the armature you have to select the armature and go into pose mode
-Then in the properties menu look for Bone constraints
-Add constraint, then select copy rotation (or copy location), after that you can select the target (in this case the corresponding cloak panel object)
-To run the constraints in-game add an armature actuator in the logic menu, set it to “run armature”

ohhh now it makes more sense,the rest of it is just a pain in the neck to figure out the positions,any tips regarding that?
thanks a bunch

ok im still trying to fix the deformation or rotation messed up,how can i fix or align in the right rotations,where do i see that? any help is greatly appreciated!

btw when i use the run armature it works haha it deforms the cloak ^^

I have been trying to make a rope… unfortunately, when I add the copy rotation constraint to the bone, the rotation is completely another one from the parent object.

Then I tried to rotate the bones in edit mode, so the axis would be according to the rotation of the parent object… same shit again.

here’s the file: http://www.mediafire.com/?25y2q67ybk8lk5z

If you could take a look, I would thank you a lot!

Greez André

And by the way… maybe you could also tell me, why my blender crashes everytime, after deleting the kite-lines and when I start then the game… bizarre

:evilgrin: Patience :evilgrin:

copy rotation/location would indeed have been nice :(, so best keep it simple (rotate bones a fixed number of degrees, pick nice numbers)

Display the bone axes (armature => object data => display)
First create the bones, then for each bone:
-set origin to start of the bone (shift S)
-Add a cube
-rotate it to align with the bone axes
-Move the cube along the local y axis, halfway of the bone (remember the amount moved to set the pivot of the rigid body joint in the opposite direction along the y axis)
-Scale the cube in edit mode to a suitable panel size

Finally connect all the panels together with rigid body joints and set up the copy rotation constraints, small alignment errors should not matter that much

Nice thanks for ur suggestions Wraaah,ur tecnique was the only one which best suits to my game ,its just perfect,i havent build the constraints to my character yet coz ive been busy with other stuff in the game but im planning to start building it in 2 days,and just to show u how constraints can really be powerful,look at this guy video : http://www.youtube.com/watch?v=senepya_96c&feature=related he created the car physics without python just using constraints and there are other videos with the same topic,its amazing how blender can be powerful even for those who dun know much of python like me hehe…but ill defenetly have to learn it very soon…anyways have a look at the video its worth it :d
all the best,