new offset anim method

1.2.0

- changed: curve offset on base 100 (allow multiple action with same curve path animation range)
- changed: offset animation extrapolated by default (for potential motion blur at start and continue after curves end)

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+1.2.0
+
+- changed: curve offset on base 100 (allow multiple action with same curve path animation range)
+- changed: offset animation extrapolated by default (for potential motion blur at start and continue after curves end)
+
 1.1.0
 
 - added: another method to add curve placing character in two position

OP_animate_path.py

@@ -318,11 +318,12 @@ def anim_path_from_translate():
 
     length = fn.get_curve_length(curve)    
     
+    ## steps: number of repetitions (how many times the move distance fit in the lenght of the curve)
     steps = length / move_val
 
+    ## frame_duration: number of frame for the move multiplied by the step
     frame_duration = int(steps * move_frame)
 
-
     const = root.constraints.get("Follow Path")
     if not const:
         return 'ERROR', f'No "Follow Path" constraint on bone "{root.name}"'
@@ -333,29 +334,30 @@ def anim_path_from_translate():
     if fcu:
         ob.animation_data.action.fcurves.remove(fcu)
     
-
-    ## add eval time animation on curve
     anim_frame = settings.start_frame
-    curve.data.path_duration = frame_duration
-
-    # curve.data.eval_time = 0
-    # curve.data.keyframe_insert('eval_time', frame=anim_frame) # , options={'INSERTKEY_AVAILABLE'}
-
-    const.offset = 0
-    const.keyframe_insert('offset', frame=anim_frame)
+    # curve.data.path_duration = frame_duration # set only 100
+    curve.data.path_duration = 100
     
-    # curve.data.eval_time = frame_duration
-    # curve.data.keyframe_insert('eval_time', frame=anim_frame + frame_duration)
+    const.offset = 0
+    const.keyframe_insert('offset', frame=anim_frame) # , options={'INSERTKEY_AVAILABLE'}
 
-    const.offset = -frame_duration # negative (offset time rewinding so character move forward)
+    ## negative (offset time rewinding so character move forward)
+
+    # const.offset = -frame_duration # Valid when duration is set same as curve's path_duration
+    # const.offset = -(((move_frame * 100) / frame_duration) * steps) # works and slightly more precise but super convoluted
+    const.offset = -100
     const.keyframe_insert('offset', frame=anim_frame + frame_duration)
 
-    ## all to linear (will be set to CONSTANT at the moment of sampling)
+    ## All to linear (will be set to CONSTANT at the moment of sampling)
     fcu = ob.animation_data.action.fcurves.find(offset_data_path)
     if fcu:
         for k in fcu.keyframe_points:
             k.interpolation = 'LINEAR'
     
+    # Set extrapolation to linear to avoid a stop # TODO: maybe expose choice ?
+    fcu.extrapolation = 'LINEAR' # default is 'CONSTANT'
+    # defaut to linear (avoid mothion blur problem if start is set exactly on scene.frame_start)
+
     ## set all to constant
     # for k in t_fcu.keyframe_points:
     #     k.interpolation = 'CONSTANT'

OP_setup_curve_a_to_b.py

@@ -60,7 +60,7 @@ class UAC_OT_create_a_b_step(bpy.types.Operator):
 
         a = markers[0].location
         b = markers[1].location - a # remove a postion to get position in curve object space
-        
+
         # Set the curve and constraint
         curve = fn.generate_curve(location=a, direction=b, name='curve_path', context=context)
         settings = context.scene.anim_cycle_settings

__init__.py

@@ -4,7 +4,7 @@ bl_info = {
     "name": "Unfold Anim Cycle",
     "description": "Anim tools to develop walk/run cycles along a curve",
     "author": "Samuel Bernou",
-    "version": (1, 1, 0),
+    "version": (1, 2, 0),
     "blender": (3, 0, 0),
     "location": "View3D",
     "warning": "",