MAYA // Twist start end IK spline without advanced twist controls

twist from start :
set attribute on ikHandle like this : twist = roll * -1
for example, roll=150 and twist=-150

setup exemple where MD_invert_roll_1, input2X is set to -1

MAYA _ replace skinned mesh

To replace a skinned mesh by another : SKin -> Substitute geometry
very useful to replace with a High Res Mesh or when a mesh is messed up (uv,normals) it also keeps the deformer but not the blendshapes.  source A   source B

MAYA _ Ik spring solver

Ik spring solver is useful on  multiple joint chain for proportional or custom rotation of the joints with the ik. Just enter this mel command to be able to create them : ikSpringSolver;

MAYA _ IK pole vector constraint joints move

Sometimes when applying pole vector constraint on a RP IK, the joints move, here is the fix :

"The fix, as it turns out, is really easy. Before you apply the pole vector constraint, you need to place your controller (whatever is going to drive the pole vector) exactly between the start of the IK chain, and the end effector, e.g., the shoulder and the wrist. This is quickly done by selecting the start and end joints, and then the controller, and creating a point constraint (do not maintain offset). Then delete the constraint. Next, use an aim constraint to point the controller directly at the middle joint (say, the elbow). Delete the constraint. Then you just need to move the controller along its pointing axis a little ways, to push it away from the bones. For example, if your aim vector for the constraint was +X, then push your controller a few units forward in its local X axis. Now you can create the pole vector and the joints shouldn’t snap at all."

from http://www.toadstorm.com/blog/?p=129

MAYA_clean motion path to constrain on curve

1. Create your motionPath as you normally would

2. Select the "motionPath1" node in you Channel Box inputs and you should see "U Value" and it should be keyframed. Select that attribute and Break Connections to kill the animation. This "U Value" is just like "Parameter" in PointOnCurveInfo nodes in that it will move your connected object along your curve using values 0-1. You think it would be that simple but you will likely get Cycle Check errors.

3. To clean up the setup and avoid errors you can use the connection editor to connect motionPath1 (allCoordinates "xyz") to the translate "xyz" values of whatever object you have attached to your path, and then simply delete the 3 addDoubleLinear nodes that are no longer necessary.

This leaves you with your curve->motionPath->attachedObject and also gives you all the other options that are built into the motionPath node like Follow, Twist, etc. I usually attach locators to motionPaths rather than directly attach objects and also like to use setRange nodes to expand the 0-1 value of "U value" to something more friendly to interact with like 0-10 or 0-100

Image in the Node Editor:
andrewandoru.com/images/motionpathrigging.jpg

source - Andrew Hake

MAYA _ Skin with a curve

To skin with a curve and deform with the control vertex :
- select a joint and the mesh -> bind skin -> smooth skin
- select the curve and the mesh -> edit smooth skin -> add influence option : check Use geometry
- go to the skin cluster and check Use component

MAYA _ surface attach/rivet

To create a locator that follow a face, in plugin manager load muscle, select two edges on your mesh, then :
Animation > Muscle > Bonus Rigging > Surface Attach

or use a follicule
vimeo.com/47456885

MAYA _ float value annotation in viewport

Annotation node can't have float value, only string. So to display a value in viewport:
- dynamic- particles - particle tools : create one particle
- select particle shape and add a float attribute toto
- particleshape - render attribute - particle render type : numeric
- attribute name : toto
- then connect any value (like scaleX) to toto