Transition Editor

Select a biped > Motion panel > General rollout > Motion Flow Mode > Motion Flow Script rollout > Select a clip in the list window > Transition Editor

Display the Transition Editor by selecting a clip in the list of the Motion Flow Script rollout and clicking Edit Transition on the same rollout or right-click a transition arrow in the Motion Flow Graph.

Transitions

A good transition links two clips together seamlessly, the motion through the transition should appear natural, as though the motion was captured as one long motion sequence. Like an AB roll transition in video editing, an appropriate section in both clips is selected for the transition (dissolve) from the source clip to the destination clip. Velocity differences between the source and destination clips are matched during the period of transition producing a seamless result. By default, Minimum Motion Loss is used to find likely start frames in the source and destination clips when clips are appended to a script. Optimized transitions can be computed by using Optimize Transition in the upper right hand corner of the Transition Editor dialog. Optimized transitions use a minimum foot sliding method to compute transitions. Optimized transitions take longer to compute, but yield better results.

Although only one arrow is used to represent a transition between two clips in the Motion Flow Graph, any number of transitions can be named and stored in the Transition Editor representing that transition. If, for example, you create 5 different transitions between two clips for one script, all of these transitions are available in a new script that uses the same two clips. Think of Motion Flow Graph as a data storage area; if all of the scripts are deleted, the transitions are preserved and can be stored in a .mfe file.

Automatic Transitions

When you create a script, default transitions are used between the clips. Default transitions use minimum motion loss and are quick to compute. However, the best quality transitions are the optimized transitions. Once the Transition Editor is open, the first thing to try, before manual editing, are the optimized transitions (upper-right corner of the dialog). Optimized transitions use a minimum foot sliding algorithm to compute the transition and yield very good results.

Length (Transition Duration)

Set the duration of a transition in the Length field. A value of 10, for example, creates a transition of 10 frames between the source and destination clips. During the period of transition, the velocity of the source clip is interpolated to the velocity of the destination clip. If the transition takes place at the last frame of the source clip and the first frame of the destination clip, and Length is set to 10, then the last frame of the source clip is interpolated with the first 10 frames of the destination clip.

Editing Transitions Manually (Ghosts)

Manually setting the Start Frame for the source and destination clips offers the most control. Unwanted motion in either clip can be avoided and judging the best Start Frames for both clips is left to you.

The Ghost area Frame spinners allow you to view and scrub the source and destination clips by displaying stick figures (ghosts); yellow and red stick figures represent the source and destination clips. When a suitable Start Frame is located for both clips, use Set Start Frame in the Ghost areas to copy the Frame values to the Start Frame fields in the Source and Destination Clip areas.

Scrubbing the time slider over the transition period enables you to view the biped's transition from the yellow stick figure (source) to the red stick figure (destination).

Other Transition Editor Features

Rolling and Fixed specify whether a clip is rolling (in motion) or fixed (single frame) during the transition. Change the direction of the destination clip using the Angle field.

Other parameters in the Transition Editor allow you to create and name new transitions, scroll through the saved transitions, Jump to the transition-starting frame, set automatic transition parameters and go to the next transition in the script

All transitions and their attributes are saved with a .mfe file.

Procedure

To create a manual transition between two clips

  1. Select a biped and turn on Motion Flow mode on the General rollout.

  2. Create or load a script with at least 2 clips.

  3. Select a clip in the clip list on the Motion Flow Script rollout.

  4. Click Edit Transition to display the Transition Editor for the selected clip and the clip following it in the list.

  5. Scrub the Ghost area Frame spinners in the Source and Destination areas to find a place in both clips to start the transition.

    Two stick figures appear to help you find an appropriate start frame.

    The stick figures may be positioned far apart during this process, this does not matter, look for body motions in the two clips that will transition well.

  6. Click Set Start Frame in both Ghost areas when a good Start Frame is located.

    character studio repositions the destination clip for a best body fit between the two clips.

  7. Set clip duration in the Length field.

    Clip duration of 10 to 25 frames is normal.

  8. Click OK.

  9. Click Play or scrub the time slider to view the transition. You should see one red bone biped (the destination clip), one yellow bone biped (the source clip), and a biped that has the motions of the synthesis of the two clips.

Interface

Probability: Set a probability value for the transition. This is used by Create Random Motion when a random script is generated.

Length: Sets the number of frames for the duration of the transition.

Transitions are calculated by matching velocities in both clips. Smooth out abrupt velocity changes using longer transitions.

Angle: Sets the direction of the destination clip.

The angle of the destination clip is automatically set for best body fit between the two clips when the Start Frame values change. Use Angle to change the direction of the destination clip.

Ease In: Ease in value for the source clip.

Ease Out: Ease out value for the destination clip.

Previous Transition: Go to the previous transition in the script.

Displays the previous transition in the Transition Editor, moves the time slider to the start frame of the previous transition and highlights the previous clip in the Motion Flow Script list.

Next Transition: Go to the next transition in the script.

Displays the next transition in the Transition Editor, moves the time slider to the start frame of the next transition and highlights the next clip in the Motion Flow Script list.

Optimize Transition: Displays the Transition Optimization dialog.

Options in the Transition Optimization dialog allow you to search for the location for the transition.

Go To Start Frame: Moves the time slider to the first frame of the transition.

The number field shows the start frame number.

Start Frame: Set the transition start frame for the source and destination clips in their respective fields. Duration for the source and destination clips display above the Start Frame fields.

Rolling: Keep the clip in motion during the transition.

Fixed: Freeze the biped at the Start Frame position during the transition.

Ghost group

The Ghost area Frame spinners allow you to view and scrub the source and destination clips by displaying stick figures (ghosts); yellow and red stick figures represent the source and destination clips. The source and destination bipeds may not be close to each other during this scrubbing process; the destination clip will be repositioned when Set Start Frame is clicked. When a suitable start frame is located, click Set Start Frame to copy the values in the Frame field to the Start Frame field. Monitor foot position status in the field provided.

Set Start Frame: Copy the value in the Frame field of the Ghost area to the Start Frame field in the Clip area. The position of the destination clip changes to match the biped body in the destination clip to the biped body in the source clip.

Locate an appropriate start frame for the source and destination clips by using the Frame spinner and viewing the positions of both stick figures, then click Set Start Frame.

The destination clip is rotated and positioned to match both bipeds. Use the Angle spinner to reorient the destination clip.

Frame: Use the Frame spinner to scrub a stick figure back and forth, which allows you to determine a start frame for the source and destination clips. Visual feedback of the stick figures is a good way to judge which start frames are needed for the source and destination clips.

Create Transition: Click to create a new transition. The transition number field increments. Edit and name the new transition. Any number of transitions can be stored.

Note: Clicking OK saves the displayed transition. Create Transition is used only if you want to work on a new transition.

Delete Transition: Click to delete a transition.

Previous Transition: Go to the previous stored transition. This button is grayed if no previous transition exists.

Next Transition: Go to the next stored transition. This button is grayed if no next transition exists.

Ok: Store transitions and exit the dialog.

 

 

 


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