1. Computer Graphics Imaging Ying Zhu Georgia State University Lecture 23 Walk Cycle, Action Editor, and NLA Editor

2. Walk cycle A walk cycle generally consists of four key poses – Contact – Recoil – Passing – High-point – See http://www.blender.org/documentation/htmlI/x8 053.html http://www.blender.org/documentation/htmlI/x8 053.html – Let Blender interpolate between these poses

3. Create a walk cycle The process – At the start frame, create the “rest” pose. Select all the bones that have been moved, press I to insert a key frame. – Increase frame number. Create the “Contact” pose. Select all the bones that have been moved, press I to insert a key frame. – Increase frame number. Create the “recoil” pose. Insert a key frame. – Increase frame number. Create the “passing” pose. Insert a key frame. – Increase frame number. Create the “high-point” pose. Insert a key frame. – Repeat the above process until the character reaches the original contact pose.

4. Create a walk cycle Select a bone (or bones), open the IPO Curve Editor – Choose “Pose” IPO type – You’ll see the IPO curves for the bones

5. Copy and paste poses In Pose mode, select Pose menu and choose – Copy Current Pose – Paste Pose – Paste Flipped Pose “Paste Pose” is useful for copy and paste the same pose in a walk cycle “Paste Flipped Pose” is useful for creating mirrored pose in a walk cycle – E.g. reversed leg position Can also use the copy/paste icons

6. Combine walk cycles with path Two ways to create a walk cycle – Move the character forward while you create the walk cycle – Create the walk cycle without move the character forward In latter case, you can attach the armature with a path – Create a path – Select armature and then the path, press ctrl + P – Choose “normal parent” (not “follow path”) – The character will walk along the path

7. Action Editor Three editors are used in creating complex character animation – IPO Curve Editor – Action Editor – NLA Editor Each is built on top of another and handles a different level of task

8. Action Editor IPO Curve Editor deals with the animation of each bone – A user creates a pose and insert a key frame – An IPO curve interpolate between key frames In Action Editor, you can create individual “action” – An action is a sequence of poses that serve a purpose (e.g. walk, wave hand, rest, etc.)

9. Action Editor To create an action you create a sequence of poses and insert key frames In Action Editor window you’ll see a number of channels – Each channel represents a bone – A diamond marker is a pose marker – Each vertical line represents a complete pose – Along the time line, pose markers are interpolated by the IPO curves to see them you need to switch to IPO curve editor

10. Action Editor You can give each action a meaningful name To add a new action, click on the button next to the action name and select “ADD NEW” – Then you create another set of poses and insert key frames, and so on.

11. NLA Editor NLA stands for “Non-Linear Animation” NLA Editor is a level above the Action Editor It allows you to organize and mix the actions you created in the Action Editor – Organize actions along time line (If you see a blank window when you enter NLA Editor, press Home or Shift + MMB to scroll the window up and down.)

12. NLA Editor Select an armature, move the green line to the starting frame, press Shift + A to add an action strip – Choose an action from a list These are the actions you created in the Action Editor – You can move and scale the action strip Press Shift + A to add more action strips – Organize them along the time line to create a logical sequence of actions

13. NLA Editor Action strips may overlap at some point – E.g. “wave hand” in the middle of a “walk cycle” In many cases, you want one action to ease into another action – E.g. walk  run  walk  rest

14. “Ease in” and “Ease out” in NLA How to set up “ease in” and “ease out”? – Place two action strips so that the end of one action overlaps with the start of the next action by a number of frames (e.g. 15-frame overlap) – Right click to select the first action – Press N to bring up the “Transform Propoerties” menu – Press “Auto-Blending” – In the “In” field, type in the number of overlapping frames (e.g. 15)

15. “Ease in” and “Ease out” in NLA How to set up “ease in” and “ease out”? (Cont.) – Right click to select the second action – Press N to bring up the “Transform Propoerties” menu – Press “Auto-Blending” – In the “Out” field, type in the number of overlapping frames (e.g. 15)