Large mesh does not move along with the rig (Rigify)

Hello

I am relatively new to Blender and want to use it to change the pose of a 3D scan of a person.
The Mesh of the 3D scan is detailed (2Million faces >200MB file) and I wonder if this is causing a problem.

I installed Blender and riggify and followed some tutorials like “Rigging in Minutes with Blender’s Rigify Addon” on pluralsight or “How to use Rigify rigging tool in Blender 2.80” on YouTube
I followed the steps in the first tutorial with the warrior_character and was able t pose that mesh without issues. Doing the same with my 3D Scan does not work.

As far as I understand the basic steps are:
-load your mesh
-add a human metarig
-move all the bones to match the arms fingers and so on
-create a rig with the “Generate Rig” button (and hide the metarig since it is no longer used)
-select the mesh first, than shift+ select the rig, then press ctrl+ p for the “set parent to” menu and select “with automatic weights”
-in pose mode I can change the pose of the rig but the mesh does nothing (even if I wait patiently).

the last step takes a while (~25minutes) but eventually finishes without any error messages. I am not 100% sure if the parenting step worked, is there a way to check this?

Here is a link to my file with the metarig before i create the actual rig.

Yes, the fact that it is 2 million verts is the problem.

Autoweights break down at certain vert densities. If you check your debug window, you’ll probably see that autoweights failed.

Nobody much cares because performance for animating a 2M vert model is out the window bad anyways. Nobody wants to pose a 2M vert model. You can see that-- even if weights did take, it would take that long to update the mesh.

Plus, as a 3D scan, the edge flow is probably shit. Even if you did rig and pose it, it would look bad.

Retopo the scan.

Didn’t look at the file.

I would not mind if changing the pose takes forever, since my plan was to alter the pose just once.
Then I would cut the model into cubes and use a 3D printer to create a lifesize mannequin.

I guess I have to reduce the vertices without losing too much detail. There are a lot of free tools available. Any idea what the maximum number of vertices would be that can be used?
I just tried 130k, that can be used but the loss of detail is definitely visible.

If you want to pose it only once, what I’d recommend doing is making a bare-bones low poly out of extruded cubes, rigging that low poly, and mesh deforming from that low poly.

If you do that, you can get away with a pretty half-assed job for a single, uninterpolated pose.

If you haven’t retopo’d a model before, I would recommend just downloading a low-poly naked character from somewhere, roughly scaling into shape, shrinkwrapping to your model, and then dragging verts out by their normal until your high poly is fully enclosed.

An alternative would be to use the new sculpting tools in 2.81 that allow armature-like posing. I haven’t experimented with those myself.

You could weight paint manually, but it would be irritating.

I can now rig and pose the model with a quality that is definitely good enough for the task of scaling 3D models to the body (to turn in game graphics into costumes).
I still need to put the texture back on the model but I already found some solutions in this forum.

For the full resolution model I now have a few ideas. Thank you for the support!
I will watch a few tutorials about retopology and shrinkwrapping.
Sculpting and deforming might also be a good option since I do not need to change a lot. Moving the arms closer to the body and the legs closer together should not be that hard.
The head that has the most detail does not need to be deformed. I can probably use the lower resolution model in the correct pose as a guideline for the high resolution model.