Rigging question: separate meshes or not in rigging

Hi mates,

I have a rigging dilemma. It turns out that I have a model that was originally a single mesh, but that I have broken up into pieces because it combines hard (armor) and soft (body) parts intermixed.
I have weighed the soft parts with automatic weights: CTRP / Armature Deform with Automatic Weights, whose weights I have adjusted manually afterwards.
To the hard parts, I have separated them from the initial body, in Edit Mode / Vertex Groups / Remove from all Groups to clean all influence, and then in Pose Mode, I have parented each one to the closest bone using: CTRP / Bone Keep Transform
The problem arises when moving certain controllers of the rig, the separation between hard and soft parts is seen (since I have separated the meshes)
(Image when moving hip controller showing the separation between meshes)

I have tried to rig all the gaps between some parts and others, with different bones, to 100% by weight (100% influence), but they always end up being gaps between the hard mesh and soft mesh, whether in one type of animation or another.

So, my question is: If you had a model that continuously intermixed hard (non-deformable) and soft parts, would you separate these parts into different meshes? If not and everything is the same mesh, how would you make them hard parts not deform? and still follow the movement of the rig (despite not having weights)?

I would not separate, no. Not for the final model, not for the vert count you’re demonstrating and the kind of model that vert count suggests. (You can separate and rejoin stuff all the time while getting there. “Single object” is not some immutable thing…)

In order to make the hard parts not deform, I would weight them by starting with autoweights or something, selecting the hard bit, selecting a central-ish vert of that bit as the active selection, and then hitting the “copy” button on sidebar/item/vertex weights. The hard bits would definitely have weights, they’d just have uniform weights.

This would probably require tuning the weights of the soft bits a bit near the borders, so there wasn’t undue stretching, which would have to be by hand. A single iteration smooth might do it, but you’d only want the smoothing to come from the hard bits, so there’s someplace where you might make a temporary edit of the model (separating bits out) and then data transfer your weight edits back on. Depending, I guess. Eyeballing it is fine too.

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Thanks mate, finally I followed the advice of making it in a single mesh and I got to a satisfactory result of deformation in all poses.