corrective blend shapes in Maya for muscle deformation and cloth wrinkles and skin weighting.

As you can see in the previous post i didnt skin the high poly very well, in fact i just left the default skin weights and ended up with this


This is similar to what you might get at the elbow or knee joints. Sone good skin weight adjustment would fix this fine but it is possible to fix this by using corrective blendshapes instead. I created a blend shape for the cylinder and the adjusted it at the bent position so that the mesh was not collapsing on itself.



I then set driven keys so that the rotation of the joint turned the blendshape on.

As i said before you can do this with skin weighting so why use this method? Because it can be used to create effects like muscle bulges and cloth wrinkles as well as correcting hard to weight areas.

Referencing in Maya using proxies and high poly models and jazz like that

To enable me to animatie while the others are still modeling we will be using referencing. This means that we can create low poly proxy models for me to animate and he replace them later with the high res meshes.

Here is an example using a cylinder.

Low poly mesh with joints, the mesh is parented to the joints rather than skinned as it is broken into two parts. as well as saving time skinning, it means that maya will run faster while I animate as it doent not have to calculate the skin weights all the time.



I saved the scene as "low poly" and then in a new scene loaded it as a reference


I then animated the low poly version

I saved this and then went back to the low poly file and created i high poly version of the cylinder that fitted over the lowpoly



After skinning the high poly i saved the scene as "high poly" and went back to the animated scene. I then replaced the low poly reference with the "high poly" scene


Because the joint names are the same in both the high and low poly scenes the animation carries across. It is even possible to create the high poly and then overwrite the low poly file and then reloading the reference instead of replacing it.

Making accurate train tracks in Maya

I originally thought the tracks would be easy to make by just extruding along a curve. Turns out that just doing that can cause some problems when it comes to accuracy.

Firstly I made a cruve to represent the path of the tracks.

Then I created two cubes that the tracks could be extruded out of.

Just exturding one face out at a time doesnt work because it move the extruded faces to follow exactly along the curve like this


Combining the cubes and the extuding the faces at the same time works if the track is straight


However, as soon as the curve bends you start to get some unwanted twisting in the tracks

I thought a way to possibly solve this would be to have to separate curves so that each rail of the track could be extruded separately. Simply duplicating the curve however only works if the track is straight

At the bend the curves get closer to gether and are no longer parellel

One way i found to get around this problem is to make an object that represents the cart (or something that can follow the curve) I chose a cube. I duplicated it twice and then moved the pivots of the duplicates so that one was horizontally parallel to one rail and the second was parallel to the other. I then attached both to the curve using attach to motion path.

Moving the pivots meant that the duplicates wouldnt just follow the curve along the middle like what you get when extruding one rail on its own. Instead, they follow paths that stay the same disence away from each other at all times. I then created motion trails from the duplicates



Here you can see hoe they stay the same distance apart all the way along



Next, the motion trails can be converted into curves and the rails extruded along them to create an accurate track!

There may be a way more simple way to do this but i didnt find it! maybe im just stupid?

Rigging in Maya

The way we plan to work is to use proxy versions of the characters to animate while the high res versions are being made. Ill use dans drawings to make the proxies to the same proportions as the drawings and then send them to Dan and Anna to make the high res, using the proxies as guids as well as the drawings. For rigging i found a mel script that automatically creates controllers for a skeleton. Its totally customisable so can be added to if needed. It might seem like cheating, but its not! I know how to set up everthing the script does so all its doing is saving time.



Above is the UI for the script. You just need to type in the name of the corrsponding joints and it will create the controllers for each one. Below shows some of the controllers on a bunch of joints.



Get the script from : http://www.highend3d.com/maya/downloads/mel_scripts/animation/zooCST---character-setup-toolkit-2874.html