Monday, 29 September 2014

Semi Auto Skinning R&D

If you have not already seen Hans Godard's vimeo page then you should go there now. That man does some great work and is a huge inspiration.
His latest video demos a workflow for automatizing smooth skinning. I tried to do something similar but couldn't crack the math for SSD. So I did it my own way. The most important thing is that it works and gives good results.

My version is based on Splice and Python. Python slows things down a lot but I am getting into C++ so the next version will be full Maya C++ API.
Even with Python I didn't have to wait too long. With a 12k vert mesh and 85 skinned joints the procedure was done in a bit more than 5 minutes 3m30s (did some optimizing). That still beats doing it by hand and painting the weights until the wrists start to hurt.

A big thank you to Jonas Törnqvist for giving me the model for testing. Great modeler and a great guy.

No more talking, here is the video:

semiAutoSkinningRD from Armin Halac on Vimeo.

Sunday, 14 September 2014

Tangent Spine

Combining the best out of FK and IK spine rigs and adding even more. IK/FK spines are allow much control over the torso but are tedious to animate. A lot of layered controls on top of each other can require some counter rotating and produce gimble issues. With this setup the animator can rotate from various points on the spine. Similar to FK but FK requires the user to distribute the rotation across multiple controls if fluid shapes are required. And they always are.
On my setup most of the posing is handled with the rotation of the two main controls and can be further refined using the tangent controls and the translation of the main controls.
Advanced volume preservation controls plus the IK like behavior that can be achieved with this setup are great for stylized animations.

See it in action:

Tangent Spine Rig from Armin Halac on Vimeo.

Monday, 8 September 2014

Variable foot rig

The foot is one of the areas that doesn't get special attention when rigging a character. Many rigs have the standard inverse foot setup that makes the animator slide a bunch of attributes and try to get something they like.

 I like to keep everything on the character without messing too much with sliding numbers in tiny boxes. That way the animator can quickly experiment with poses and get organic shapes.

Here is the setup I came up with:

Variable foot from Armin Halac on Vimeo.

As seen in the video the foot is really flexible and allows for easy posing. The bend control can moved to any point along the foot and make the foot bend in any direction. The only slider that requires the animator to take his/hers eyes of the character is used to control the falloff. Falloff control allows the foot to peel nicely from the ground or to bend at a harsh angle. The foot uses the same rig for both IK and FK modes.

The model is owned by Irie Studios.

Monday, 1 September 2014

Revolve node

One more custom node done in Fabric Splice. This time I tackled a couple of things at once.

First was wheel rotation. This solution is based on the objects world matrix instead of a position value or something similar. The idea was based on one of Rigging Dojo's AIR sessions with Raf Anzovin. The object can have as many controls as you want and it will always calculate the correct roll. I added the possibility to connect a parent inverse matrix so the setup can be a child of some other node. Useful when having world positioning controls on a rig.

The next was a parameter to drive objects along a curve. Similar to the rotation, only the output is different. Instead of outputting an angle value the parameter is a value between 0 and 1.

And the last was instancing. A mesh will be projected on the custom splice curve and it is driven by the parameter value. I extended the BezierXfo class that comes with Splice and added a new function that takes a number of instances and a starting offset as the input. In this case parameter is that offset and it tells the function where the first element should be on the curve. Then the other elements are projected onto the curve with an equal distance between them.

Check out the video bellow to see the node doing its thing:

Revolve Node in Maya from Armin Halac on Vimeo.