Skeletal rigging, movement, deformation?

[Anonymous]

I am a hobbyist, trying to use Fusion 360 to design the mechanism for a robotic powered exoskeleton, which will closely conform to the shape and movement of a real human body. It's nothing too ambitious, really...  

I need a movable and posable model of a human body to work with, in order to design the mechanism and make sure it will move in an accurate manner. I need to be able to attach the mechanism to the limbs of the posable human body, and to be able to move the human rigging, and have the mechanism move to match. Simple solid-body posable marionettes of a human body are unacceptably inaccurate.

I am able to obtain precision anatomical posable human models from DAZ 3D, but so far I have been unable to figure out how to get this to work within Fusion 360.

When the posable model imports into Fusion 360, the skeleton / rigging is stripped out, and it turns into a solid immobile statue that is useless for what I am trying to do. If the human mesh cannot be moved then there is no way to test the exoskeleton mechanism for self-collision or over/under extension.

How can I make this work?

,

Posable human models (newer versions are more anatomically accurate):

DAZ 3D / Michael 6 -- http://www.daz3d.com/michael-6-pro-bundle

DAZ 3D / Michael 5 -- http://www.daz3d.com/michael-5-pro-bundle

DAZ 3D / Michael 4 -- http://www.daz3d.com/michael-4-pro-bundle

So let's take Michael 4.

Load the default posable shape into DAZ 3D.

Export as AutoDesk FBX format.

Import into Fusion 360

Skeleton and rigging is stripped out and it turns into a statue.

,

I tried exporting as the AutoDesk FBX ASCII format, and when I look through the FBX text file, I can see that it contains skeleton / rigging information, but it is being stripped when the FBX is imported into Fusion 360:

,

Model: 238973376, "Model::hip", "LimbNode" {
Version: 232
Properties70: {
P: "RotationOffset", "Vector3D", "Vector", "",0,103.875999450684,0
P: "RotationOrder", "enum", "", "",2
P: "RotationActive", "bool", "", "",1
P: "ScalingMax", "Vector3D", "Vector", "",0,0,0
P: "DefaultAttributeIndex", "int", "Integer", "",0
}
Shading: Y
Culling: "CullingOff"
}

,

PoseNode: {
Node: 836840288
Matrix: *16 {
a: 1,0,0,0,-0,1,0,0,0,-0,1,0,-78.5281677246094,142.169006347656,15.995587348938,1
}
}

,

Deformer: 236764304, "SubDeformer::", "Cluster" {
Version: 100
UserData: "", ""
Indexes: *114 {
a:

LONG STRING OF NUMBER DATA REMOVED

}
Weights: *114 {
a:

LONG STRING OF NUMBER DATA REMOVED

} 

Transform: *16 {
a: 1,0,0,0,0,1,0,0,0,0,1,0,78.5281677246094,-142.169006347656,-15.995587348938,1
}
TransformLink: *16 {
a: 1,0,0,0,-0,1,0,0,0,-0,1,0,-78.5281677246094,142.169006347656,15.995587348938,1
}
}

- Dale Mahalko

[TrippyLighting]

I don't work in Poser, but have some 10 years of experience in Blender. In Poser the mesh you are working with is rigged, meaning the mesh elements are assigen to a bone structure, possibly weighted. When you then animate a bone the mesh moves with it.

You cannot do that in Fusion 360. Fusion 360 is not an Animation Software that works with such a bone/sekelton system.

I would believe that the complete figure can be exported from Poser into another mesh modeling software in a format that also includes the bone structure (COLLADA ?)

You could mesh model the exosteletton that mesh modeling software e.g. Blender, Modo, 3DS Max, Maya etc.

Then you can export/import the control (quad) mesh for the mesh-modeled exoskeleton as a .obj into Fusion, convert it into ta T-Spline and add mechanical features.

You could on the other hand "disect" your digital human model and detach the limbs and split them in upper arm, lower arm, hand ec and join them with Fuinon Joints. This would make the figure poseable similar to a manequin. I hope all the faint hearted have not passed out at this point 😉

In whole that's a lot of skills to be acquired if that is your first project!

[Anonymous]

Thank you. The way you are replying is not unexpected. I was contemplating that I may end up having to model the mechanism in an imprecise non-CSG 3D modeler like Maya first, and then have to migrate the mechanism only, to CSG CAD software later.

The problem is that a simple visual modeler like Maya or DAZ 3D is probably not going to care about interpenetration or have any way to detect it, or to be able to do structural and material strength analysis.

I could design something in Maya, then bring it over to Fusion and discover in simulation that it what I worked many days / weeks to create is completely unworkable, because real-world materials simply do not behave that way or are not strong enough.

,

Would it be possible to implement deformable rigged meshes into a Fusion 360? There is no lack of mesh "surface precision" when it is deformed. All mesh changes are precisely defined in the deformation parameters.

(I expect that of course it is possible. The actual question is why it would not or cannot be allowed to be done.)

If if a rigged deformable mesh used within Fusion, it does not matter that it actually be treated as a solid body like other normal Fusion CSG objects. It can be a phantom object without a solid surface, and to which other normal CSG cut/join functions are not permitted to apply, but instead allowing only mate / joint operations to the mesh's skeleton.

I mainly just need to be able to anchor the mechanism to the skeleton for initial design purposes, and then be able to detect or be informed where the mechanism is colliding with the outer mesh/skin layer, when the skeleton and mechanism are moved.

- Dale Mahalko

[TrippyLighting]

I was explaining two possible ways to achive what you want to do with available tools now.

Perhaps in some rather distant future that could also be implemented in Fusion 360, if there is enough demand for it. that's what the idea station is for 😉

My estimate is that it may not gain enough traction to be implemented any time soon.

In general your comments indicate that you have formed an idea that is based on thoretical comcepts but is not based on any practical experience with either Fusion 360 or Mesh modeling software such as Maya, Modo, Blender, 3DS Max. You can model precise in mesh modelers. It's just usually not parametric.

I believe that starting with a Mesh modeler is really your best bet. 

In general no single tool, however sophisticated is going to solve all the engieering and prototyping problems.

This is particularly true for such an Exosceleton that has to adapt to the huge variety in the shapes and sizes of a human body.