What ought I do for a collision object..?

Thanks for taking the time to read, firstly; any advice would be greatly appreciated.

I’m in a situation where it seems to me that, despite conventional wisdom, using the armature itself as my character’s collision object (rather than an invisible mesh) is the most effective means of collision. The reason for this is that the attacking animations my character will be using, become quite intricate (rolling, jumping in specific ways) and a separate collision mesh just won’t follow the character’s shape closely enough. A jumping dropkick, for instance, requires that the collision bounds follow the character’s feet throughout the animation, whereas a separate collision mesh even with tedious rotation and force just isn’t going to cut it.

Is there an alternative to using a separate collision mesh, or using the armature as the collision object, given my particular collision needs? If, as it seems (perhaps in my naivete), the armature collision option is the best method… is there a best way of setting this up to avoid it’s pitfalls? For instance, right now, setting ‘collision bounds’ for my armature only ends up with a collision box around the origin point and not the bones, anyway…

I’ve tried extensively to research this, but I’ve just been unable to find a solution to these specific needs. If you have any suggestions, please do offer them!

I would use rigid bodies and then parent a empty to a bone, then use rigid body joint to link the “fist” to the empty

then it will collide,

or use a rag doll that the ik targets are rigid bodies,


Wompa.blend (518 KB)

Maybe create a second version of your character that is low poly, attach it to the same armature, and then turn the collision bounds on for it and use triangle collision bounds. I haven’t used an animated character in anything that I’ve done yet so I’m not actually sure if this will work, but It’s worth a try. Hope it helps;)

That doesn’t work because the collision bounds of a mesh aren’t updated when the mesh is deformed by an armature.

If you want the collision bounds to correspond to the current position of an armature deformed mesh, you need to parent individual collision objects to each bone of the armature.

Ok, well you learn something new every day. :slight_smile: I seen something in the wip forum, and it looked like something you might find use full, I’ll see if I can find it. If I do you might be able to message them directly and see what their method was.

Excuse me,
check the .blend
that is a rigid body Ik target aka procedural animations,
you can however ATTACH A RIGIDBODY using a 6dof link NOT PARENTING
I am here…

BluePrintRandom, your blend is essentially the opposite of what the OP is asking for. You have a skinned armature that tracks to physics objects and does not use any pre-made animations (basically a ragdoll). What InTheZone wants is for the collision bounds to follow an armature as it plays actions.

the second suggestion

Pin a empty to a bone with parent,
use a rigid body joint to pin a rigid to that


Demo.blend (434 KB)

Bump check out the new blend


MotorConcept.blend (428 KB)

Added another example

For a punch or a kick, I would set up one or two hit spheres (using sphere collision bounds) parented to bones of the armature. No need to get super fancy.

@BluePrintRandom: Dude, when will you learn to edit your last post instead of posting three times in a row? Multi-posting creates clutter, and is annoying.

Thank you all for your suggestions.

I’ve tried implementing the options presented here, and I’m currently at laser blaster’s suggestion (if I’ve understood correctly). I’ve created an empty cube for each bone necessary (feet, lower legs, upper legs, hips, lower spine, upper spine, head, upper arms, lower arms and hands), and parented each of these to the corresponding bone. I’m not seeing collision with these, though they do follow the bones.

I’m not sure what the empties should be set to, in regards to physics, to achieve collision. Setting to dynamic, they collide with each other even if I set them all in collision group 2 and set their collision mask group to group 1 only.

If I’m to pursue this, will I only be able to create separate collision empties for hands and feet, to avoid collisions with all other empties? Once again, due to the very diverse animations, any of the above listed bones could be responsible for collision with the target object.

I’ve been stuck trying to research and remedy this for a month now, so I very much appreciate all of your help.