FCurve Details Constraints

FCURVE EDITOR AND CONSTRAINTS

Note: This page will in the future include subposes

Today we’re going to get into the technical, the fcurve editor and constraints. In preparation lets look at the trailer for a movie that used a lot of technical animation the upcoming movie Gravity…
[iframely]http://www.youtube.com/watch?v=EPAibX5Mexo[/iframely]

 

TODAYS CLASS

Constraints
FCurve Editor Technicalities

 

TODAY

1. Constraints
2. FCurve Editor Technicalities
3. Lighting Morpheus and Continuing your Animation

 

FILES

(right click download)
Morpheus Unlocked With Lighting and BG Rig

 

LIGHTING MORPHEUS

We now have some nice lighting for Morpheus. To make things easy the new rig has all the lighting and bg included. But we still have to do a few things to make the lighting work.

1. Copy the new rig morpheusRig_UnlockedLighting.mb into the scene/rigs folder

2. Delete the existing stage or BGs in your scene, everything except for the morpheus rig.

3. In the Reference Editor replace the current rig with the morpheusRig_UnlockedLighting.mb

File > Reference Editor
Reference > Replace Reference

4. Now that morpheus is in our scene we’re not done yet we need to adjust some render settings…
a) Open the Render Settings
Window > Rendering Editors > Render Settings
b) Switch the drop down from Maya Software to Mental Ray*

*If not in the drop down switch it on in the plugin manager
Window > Settings Preferences > Plugin Manager
Find “Mayatomr.bundle” check on both Loaded and Auto Load

5. Now we have to make some adjustments in the Render Settings Window
a) Under the common tab
Image Format = Tiff
Frame/Animation ext: name.#.ext
Frame Padding: 4
Start Frame (set to your scene start)
End Frame (set to your scene end)
Renderable Camera m1:camera1
Trash the persp camera if it is renderable we don’t need it
Image Size
Presets: HD 720

b) Under the Indirect Lighting Tab
Final Gathering: On

c) Under the Features tab
Motion Blur (dropdown) Full

5. Now we should be able to render an image
a) go to the Render View
window > rendering editors > render view
b) render from camera1
render > render > camera1

A frame should be rendered looking as here.

Do not tweak the render settings, lights or shaders. This assignment must be rendered as is and the image should like the one above. No props are to be added either.

 

Rendering times

Rendering times should be roughly 1 – 2 minutes per frame if you have a 15 second shot you will be rendering

375 frames x 2 mins = 750 mins or…

12 hrs and 30 mins

Please leave aside plenty of time! 2 to 3 days for rendering.

 

CONSTRAINTS AND SWITCHING WORLD SPACES

 

Animating Constraints

Animating constraints between two objects is really very straight forward.

1. Shift select the multiple objects we wish to constrain to
2. Shift select then the main object we want to constrain last
3. Go to
Animate Menu > Constrain > Parent Constraint (options)
4. Tick “Maintain Offset” off and press “Apply”

When we want to change the magnet weighting of each object we can select the constraint on the constrained object find the attributes with object weighting and change/animate accordingly.

 

Mixing Keys with Constraints Film Example

Some scenes will require complex hierarchy changes in animation. While working on the previs for this sequence from Happy Feet 2 the Krill character had to be animated in multiple world spaces including sometimes parenting him to the camera itself.

I found the easiest solution was to plot out the previs animation to different world spaces using constraints but only work in one world space at a time with plotted keys. When I wanted to adjust another section of aniamtion I’d re-plot to that world space, delete keys on area’s I needed to change and reanimate from there.

This is a simple technique that came from my experience working on complicated scenes on the film Gravity.

The Happy Feet 2 scene was a tricky sequence to work on in previs/lensing becuase the director George Miller kept changing the details of the previs animation including merging shots together and re cutting as we went along. Some crazy camera moves were a real challenge to work on…

Happy Feet Two Krill Abseiling Scene. Dr D Studios and Warner Bros, many animators were involved in this scene.
http://youtu.be/kCtYNJiDbtg

 

Mixing Keys with Constraints

The important thing to remember with mixing keyframes and constraints in maya is that the action we performed last wins. So if we constrain first and then keyframe after the keyframe will break the constraint. But if we keyframe first and then add the constraint… the constraint will take priority.

Overall: Keyframes vs Constraints the one we did last wins, as seen in the demo below.

It’s important to distinguish because it’s common to use constraints to copy keys from one world space to another. This is handy for plotting world space changes like walk cycles animated on the spot into world coords. Or as I’ve found on any scene which requires animating between different hierarchies as seen above.

 

Plotting Constraints

 
 

Locking Feet On Walk Cycles

Here’s an overview of how and why we want to plot our controls from local space into world space for walk cycles.
http://www.youtube.com/watch?v=dyvOW1ZEbS8

Here’s how we can manually do this in Maya step by step.

1. Animate the walk cycle on the spot.

2. Use the MoveAll control to animate the walk cycle through space, be sure to make the feet slide as little as possible.

3. Create 3 locators in world space and plot the animation of both feet and hips. By…

a) Key the locators for translation and rotation
b) Constrain the locators individually to the hips and both feet
c) bake the animation by selecting the rotation and translation attributes in the channel box and in the fcurve editor…
curves > bake channel
d) delete the contraints

4. Delete the animation on the MoveAll control and reste it to world center. Leave keyframes on the hip and feet controls
5. Constrain the hip and feet curve controls to the locators
6. Plot out the new postion and rotation of the curve controls with “bake” as per step 3.
7. delete the constraints and the locators.

Here’s the process in this video…
http://youtu.be/DNvdjBnlaAM

There are many scripts that do this with a nice interface, one such script is Locinator by CG Monks
http://www.cgmonks.com/tools/maya-tools/locinator/

And some more tutorials here with Morpheus and constraints…
http://vimeo.com/dlatour/videos

On the short film Polar I used the same technique manually in another program called Softimage for the 3rd shot which was shared with other animators. Animating 5 Polar bears with four feet each and a long shot with deadlines and a tricky client makes for some challenging obstacles as we all found out!

Coke-a-Cola Short Film “Polar”. Animal Logic. Many animators were involved in the many walk cycles at the beginning of this short film.
http://youtu.be/WtxJft7B2ts?t=36s

 

ANIMATION SETTINGS

Changing the Frame Rate (FPS)
Window > Settings/Preferences > Preferences > Settings > Time > PAL (25fps) or other

Animation Settings for things like fcurve defaults
Window > Settings/Preferences > Preferences > Animation

Making the Timeline Bigger For Visualising Audio

Setting Keys
Set key for translate = shift w
Set Key for Rotation = shift e
Set Key for Scale = shift r
Set key for all = s
Set Key for one attribute = (right click on attribute name in the channel box) right click set key

Using the Channel Box as a slider
Click on the attribute name in the channel box.
– middle click drag in the 3d window.
– shift makes it go faste
– ctrl makes it go slower

Moving Keys in the Time Slider
To select in the time slider.
– Hold down shift and click on the key
– Hold down shift and click drag over many keys
To move
Click in the middle of the red area and drag
To Scale
Click on the tiny arrows at each end of the red selection, drag out to scale.

Setting the Default Curve Tangent to Auto Tangent Type
1. Return your default hotkeys to be Automatic in the preferences window.
Window > Settings/Preferences > Preferences
Animation > Default Tangent > Auto (for default in and out)

Returning to Stepped Keys
This is not compatible with the Morpheus Rig
– Right click > stepped mode in the timeline (to return to stepped keys)
Right click in the timeline > Enable Stepped Key Preview

How to show the Time Slider and Range Slider
If you loose the Time Slider or Range Slider
– Right click on the dotted grey area next to any toolbar. Click on
– Time Slider or Range Slider

 

FCURVE EDITOR TIPS

Framing Curves

Time Snap
Make sure time snap is on (magnet icon with ticks below)

Navigating the Graph Editor
In the graph editor you navigate like other 3d windows.
pan = hold alt, middle click drag
zoom = hold alt, right click drag
To zoom on one axis = hold alt and shift then right click drag (in the desired direction)

Move Keys in the Graph editor
Select the move tool = w
Move = middle click drag

Move Keys on One Axis
Select the move tool = w
Move = hold shift and middle click drag in a direction

Numerical Move
Select the time number input area at the top of the graph editor and type your new value.

Numerical Offset Move
Select the time number input area at the top of the graph editor.
Make sure you highlight the number for either time or value. Type the following:

To Add 10: +=10
To Subtract 10: -=10

Scale keys
Select the move tool = r
Scale = middle click drag

Scale Keys on One Axis
Select the scale tool = r
Scale = hold shift and middle click drag in a direction

Numerical Scale
graph editor > edit > scale (option box)

To Snap Keys
graph editor > Edit > Snap
or
click the time snap icon (a magnet) or value snap icon (a magnet)
and move the keys a little, they will snap into place.

Tangent Types
There’s a few tangent types in Maya the main ones are:
– Auto (Automatically tries to be smart about what your tangents should do)
– Spline (tangent point or average the next and previous keys)
– Linear (straight lines)
– Flat (flattens all the tangents)
– Stepped (for animatic and storyboard like animation, or on/off animation)

Scrub Mode
hold the “k” key and left click and drag

Scrub Mode without moving the pose
hold the “k” key and middle click and drag

Changing the Default Copy And Paste Options
It’s highly recommended to change the paste options to “merge”

1. go to the graph editor > edit > paste (options)
2. Paste Key Options > Edit > Reset Settings
3. Click on the “Help Images”
4. Paste Method: Click on Merge
Copy = “apple c” on PC it’s “ctrl c”
Paste = “apple v” on PC it’s “ctrl v”

Changing the Set Key Options
By default the “s” key is set to Key All, a better setup is to have it key the channel box’s “selected attribute” and have shift+S key all instead.

1. Animate > Set Keys (option)
2. In the window go Edit > Reset Defaults
3. Click “All Keyable Attributes”
4. In the bottom section “from channel box”

Now we want to set a hotkey for shift s

1. Windows > Settings Preferences > Hotkey Editor
2. In the Categories tab scroll down to User, this is where we can make custom hotkeys
3. Click “New” on the right hand side
4. copy the following mel into the command section…
setKeyframe;
5. Call the shortcut a name like Anim_SetKeyframeAll
6. Hit Accept to confirm the command
7. Assign that command to the hotkey “shift s”

How to Cycle a Curve
Easiest way to cycle a curve is in the fcurve editor with the icon with a curve and either a left or right arrow above. Hitting these will cycle pre or post infinity, they will also automatically switch the infinity on.

To switch off cycles
1. select the curve/s
2. FCurve editor > Pre Infinity > Constant
2. and FCurve editor > post Infinity > Constant

Toggle Infinity On/Off
1. FCurve editor > View > Infinity

Other Cycle types
Cycle will Offset = like a stair case
Linear = keeps the curve going in it’s current trajectory
Oscillate = cycles back n forth

Non destructive Inserting Keys
If we set a keyframe with any of our usual hotkeys they’re prone to slightly alter the curves. The insert key function in the graph editor is the non destructive way to add a keyframe whislt keeping our curves exactly the same.

FCurve Editor > Keys > Insert Key

or the 2nd icon from the left with the key and a + sign.

Add Keys Tool
Another nice way of adding keys is with the add keys tool

FCurve Editor > Keys > Add Key Tool

This allows us to click and drag new keys out in the graph editor

Using the Lattice
The lattice tool lets us modify curves on mass and can be handy for baked keys and motion capture.

Rippling Keys

Region Tool

Buffering Curves

Non Weighted Tangents Vs Weighted Tangents

Full Control Over Tangents
Breaking or making big or small

Breakdown Keys

Curve Isolate Curves

Selecting in the Channel Box to find curves