Compute recommended camera position based on playback stroke

[Daniel-Fan]

Working based branch:
https://github.com/Daniel-Fan/open-brush/tree/add-strokeIndicator

ReadMemory

1. Read the strokes info from memory, then add stroke into a MemoryList https://github.com/Daniel-Fan/open-brush/blob/add-strokeIndicator/Assets/Scripts/Save/SketchWriter.cs#L306
2. All the stroke is stored in that memoryList
3. The memoryList will be sorted by the timestamp of initial control point of each stroke. https://github.com/Daniel-Fan/open-brush/blob/add-strokeIndicator/Assets/Scripts/SketchMemoryScript.cs#L906

Workflow for playback

1. BeginDrawingFromMemory is used to initialize the playback object.
2. Before passing memoryList into the ScenePlayback, we should have finished the computation of camera position.
3. After the scene started, we only only to consider the redraw part, see details below
   • In Redraw(which should be used for scale change and zoom in and out), after it is sorted, we will start the ScenePlaybackByTimeLayered or ScenePlaybackByStrokeDistance

Data Structure of Stroke

1. There is a list in each Stroke called m_ControlPoints which stores the specific position and orientation of each point in this list. https://github.com/Daniel-Fan/open-brush/blob/add-strokeIndicator/Assets/Scripts/StrokeData.cs#L31
2. structure of control point https://github.com/Daniel-Fan/open-brush/blob/add-strokeIndicator/Assets/Scripts/PointerManager.cs#L70

[andybak]

I really like this idea. Is there any merit in using the headset position in your heuristic as well? You're capturing that in your branch - I wonder if that might be an interesting hint for camera position.

[Daniel-Fan]

Hi @andybak

Thank you so much for your comments!

Yes, currently we are working on an algorithm that will compute several camera view points which are based on headset position, stroke position and controller position in a certain period of time.

It will help user to keep tracking the latest playback object as well as some context at that time.