Rigging a straight leg


Hi all, it has been a while since I last touched on rigging and I am having problems with rigging the legs of a humanoid robot’s legs.

As you can see in the attachments, the leg model is pretty straight and I am placing my joints in the middle of each of the hinges of the legs. However I realized that should I be placing in an IK handle, the knee will be inwards instead of outwards.

Though I can change the position of the knee joint by placing it way further (at least further than the thigh joint), is this workflow a viable solution?

Additionally, I have one more question and that would be, should I separate all the meshes? Which is a better option - rig it as a whole mesh or rig it individually?



Well, I would either adjust the model myself or send it back to the modeler, so that the knee won’t bend backward. You can always set up the IK while the knee joint is bent forward and then reposition the IK handle so the leg joints are straight. Or you can adjust the preferred angle on the joints.

As for separating the mesh into parts or leaving it as one mesh, consider that if the mesh parts are all separated and then grouped under null objects, the groups can then be constrained to the joints. By doing that instead of skinning the mesh to the joints, it will reduce the load on the CPU.

Cactus Dan


Hi there, thanks for getting back to me.
As for the model, I am unable to send it back to the modeller as I downloaded it from a site.
I will consider moving the mesh then

As for the latter part, do correct me if I am wrong.
If the upper body is skinned whereas for the lower half I am using the grouping + parent constraint, wouldn’t that be weird? Like half skinned and half not?

This is the first time I heard of this method, thus pardon me my noob-ness in this aspect. Just wondering if this will cause any adverse problem in the rigs later on if someone is using it for animation etc?


I would recommend going for full skinned. I never liked those rigs with constrained meshes, and mixing constraints and skinning is even worse. It’s too messy. Dan’s right about the constraints reducing the load on the CPU, but seriously, Maya can handle a few skinClusters, we’re in 2014 afterall…
For me, a clean rig, is a rig that doesn’t moves the meshes’ transforms. Only the shapes, with deformers (lattice, skinCluster, etc…).


Hi Pahuska, thanks for the feedback.
I am still pretty much contemplated if a full-skinned rig is better or those with constrained mesh. Well even if the latter is indeed acceptable, under what kind of scenarios should it be used?



Well, I’m not that familiar with Maya’s performance, but if the client provides a model that is densely subdivided with a lot of intricate details to the point that it has millions (or billions :D) of points and polygons, then the constraining method might offer a noticeable improvement in the performance.

Also, in my opinion, for complex mechanical rigging with a lot of compound hinge joints, it’s sometimes just easier to rig the model parts themselves or their group parent with the constraints rather than creating extra joints in the skeleton and then skinning the model parts to those joints.

Cactus Dan


I have one more question. If my memory serves me right, I remember watching a rigging tutorial (humanoid rig) in which its body parts are ‘dismembered’ and the rigger continues to put the joints and skin it, saying something that this will gives a better control in skinning?

Is this true in any aspects?



Well, which rigging methods to use are usually dependent on how the model is constructed, and that may be what the rigger in the tutorial was talking about.

Every character model has its own unique issues. That’s why the ability to do creative problem solving is a must for riggers. :wink:

Cactus Dan