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

Walk cycle A walk cycle generally consists of four key poses – Contact – Recoil – Passing – High-point – See html html – Let Blender interpolate between these poses

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.

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

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

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

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

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.)

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

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.

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.)

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

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

“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)

“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)