# Easy question: Rigging the volume bones?

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Just for clarification, are you supposed to rig the volume bones in addition to the mbones or are you supposed to rig to the volume bones in leiu of the mbones. Or do both options work?

Thanks again.

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Briefly: You can use Collision Volumes and mbones both at the same time for weighting purposes. However it may be important to know what that actually means. Below you find an excerpt from the Avastar documentation about Fitted Mesh support

Citation from the Avastar.online website:

mBone - CollisionVolume pairs

We have pairs of (mBone, CollisionVolume) like for example (mPelvis,Pelvis), (mTorso,Torso) etc.
For those bones the sum of the weights in both weightmaps define how the bone pair influences the mesh during rotation and translation. While the weight on the Collision volume alone define the influence of the appearance sliders (scaling).

So you can distribute your weighting between the mBone and its paired collision volume without changing how the mesh behaves during animation. While the more weight you put on the Collision Volume the more influence you give to the appearance sliders.

Note: By distribute your weighting i mean that for each vertex the sum of the weights on the mbone and its paired Collision Volume does not change.

Physics Bones

We have a special set of Collision Volumes added for physics purposes (PEC, HANDLE, BACK, BUTT) Those Collision volumes are also parented to mBones but here the relationship between animation and appearance sliders is a bit more complicated. I believe the pairing for mPelvis, mTorso and mChest is like this:

• (mPelvis, Pelvis + BUTT)
• (mTorso, Torso + LEFT_HANDLE + RIGHT_HANDLE + LOWER_BACK)
• (mChest, Chest + LEFT_PEC + RIGHT_PEC + UPPER_BACK)

So you can distribute your weighting between those mBones and any or all of their related Collision Volume Bones without changing how the mesh behaves during animation. While again the more weight you put on the Collision Volume the more influence you give to the appearance sliders.

In practice

You just take your weight paint brushes and paint until your mesh behaves about right. This works for the simp[le bone/volume bone pairs (see above) without issues for large portions of your meshes. You only get trouble near the bone joints where you need to take special care about how to distribute the weights among the related bones.

The 4 weights per vert limitation

However when you add weights to the physics bones, then you can very easily get above the limits of Second life which say :

no more than 4 weights per vertex

This limitation gives you headache when you use all fitted mesh bones on your mesh

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Thank you! This helped a lot!

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