render_timeremapper.py

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bl_info = {
    "name": "Time Remapper",
    "author": "Garrett",
    "version": (0, 1),
    "blender": (2, 70, 0),
    "location": "Properties > Render > Render Panel",
    "description": "Time remaps whole scene according to an animatable"
                   "speed factor",
    "warning": "beta",
    "category": "Render",
    "wiki_url": "",
    "tracker_url": ""}


import bpy
from os import path, remove
import signal


class OBJECT_OT_render_TR(bpy.types.Operator):
    bl_idname = "render.render_timeremapper"
    bl_label = "Render using Time Remapper"
    bl_description = "This renders out frames based on your time remapping"
    bl_register = True

    # this is only used during rendering frames
    abort_render = bpy.props.BoolProperty(default=False)

    def SIGINT_handler(self, signum, frame):
        """This signal handler will be called when user hits CTL+C
        while rendering"""
        self.abort_render = True

    def execute(self, context):

        scene = context.scene

        # ensure they are using Cycles
        if scene.render.engine != "CYCLES":
            raise RuntimeError("\n\nYou must be using Cycles Render "
                               "for this script to work properly.\n")
        # ensure they haven't selected a movie format
        if scene.render.is_movie_format:
            file_format = scene.render.image_settings.file_format
            raise RuntimeError("\n\nCannot render movie file, "
                               "you must select an image format"
                               "\n(Current file format: {})"
                               .format(file_format))

        print("Getting list of frames to be rendered "
              "(should take <1 second...)")
        TR_frames = get_TR_frames(context)

        # total number of frames
        total_num_fr = len(TR_frames)

        print("\n\nRendering " + str(total_num_fr) +
              " frames now ... to stop after rendering current frame,"
              "press CTL+C...\n\n")

        # store original render path
        orig_render_path = scene.render.filepath

        # keep a count for labelling the filenames
        count = 0

        first_frame = scene.frame_start

        # before starting loop, set up a signal handler for CTL+C
        # since KeyboardInterrupt doesn't work while rendering
        # (see bit.ly/1cfBmlS)
        self.abort_render = False
        signal.signal(signal.SIGINT, self.SIGINT_handler)

        # start loop that renders the frames.
        # (anim_frame is the actual frame in animation we're at, ex: 4.5435)
        for anim_frame in TR_frames:

            print("-------------------")

            # check for frame step and skip frame if necessary
            if count % scene.frame_step != 0:
                print("Stepping over frame " + str(first_frame+count) +
                      ". (Frame Step is " + str(scene.frame_step) + ")")
                count += 1
                continue

            # render frame, ie. the number we assign this frame
            render_frame = first_frame + count

            #################################
            #  Dealing with Immune Objects  #
            #################################

            # list of immune objects that will need to have their inserted
            # keyframes deleted
            immuneObjects = []
            # Minimum frame offset. We don't want to have temporary keyframes
            # placed on integer frames (ex: 4.0, 7.0), since it could mess with
            # original keyframes.  I found this value to work well empirically,
            # any smaller and Blender treats the keyframes (4.00 and 4.01) as
            # the same keyframe.  0.03 is not a perceptible change
            # (this is a hack and could break in future releases)
            min_fr_offset = 0.03
            if using_immune_objects(context):
                # check if anim_frame is too close to being integer frame
                # and if so, push away to have minimum offset
                if 0 <= anim_frame % 1 < min_fr_offset:
                    anim_frame += min_fr_offset - anim_frame % 1
                elif 1-min_fr_offset < anim_frame % 1 < 1:
                    anim_frame -= anim_frame % 1 - (1 - min_fr_offset)

                for iobj_name in [scene.timeremap_immuneObject1,
                                  scene.timeremap_immuneObject2,
                                  scene.timeremap_immuneObject3]:
                    # check if this property is set
                    if iobj_name != "":
                        # skip this object if the user has changed the name
                        if iobj_name not in scene.objects.keys():
                            continue
                        iobj = scene.objects[iobj_name]
                        keyframe_locrot_by_target_frame(iobj, render_frame,
                                                        anim_frame)
                        immuneObjects.append(iobj)

            ########################################
            #  End of Dealing with Immune Objects  #
            ########################################

            # create filename.
            # Note that Blender expects a four digit integer at the end.
            current_renderpath = orig_render_path + str(render_frame).zfill(4)

            # check if file exists, and if so whether we should overwrite it
            # first we get the full current path to image to be rendered by
            # adding the extension if File Extensions is enabled.
            full_current_renderpath = bpy.path.abspath(current_renderpath) + \
                scene.render.file_extension * \
                (scene.render.use_file_extension is True)
            if path.exists(full_current_renderpath):
                if scene.render.use_overwrite is False:
                    print("Skipping frame " + str(render_frame) +
                          " because there already exists the file: " +
                          full_current_renderpath)
                    count += 1
                    continue
                else:
                    print("File: " + full_current_renderpath +
                          " will be overwritten.")
                    # Wait to overwrite it until last possible moment.

            # check if we need Placeholders
            if scene.render.use_placeholder is True:
                # delete the old file if it exists
                if path.exists(full_current_renderpath):
                    remove(full_current_renderpath)
                # create placeholder  (tag 'a' helps prevent race errors)
                open(full_current_renderpath, "a").close()

            # Jump to animation frame (frame is a float)
            scene.frame_set(int(anim_frame), anim_frame % 1)

            scene.render.filepath = current_renderpath
            print("Rendering true frame:", anim_frame)
            # Render frame
            bpy.ops.render.render(write_still=True)
            print("Frames completed: " + str(count+1) + "/" +
                  str(total_num_fr) + "\n\n")
            count += 1

            # Clean up after keyframing immune objects (if there are any)
            for iobj in immuneObjects:
                delete_locrot_keyframes(iobj, anim_frame)

            # Check if CTL+C was pressed by user
            if self.abort_render:
                print("\nAborting Animation")
                # reset the SIGINT handler back to default
                signal.signal(signal.SIGINT, signal.default_int_handler)
                break
        # End loop that renders frames

        # reset the filepath in case user wants to play movie afterwards
        scene.render.filepath = orig_render_path

        print("\n\nDone")

        return {"FINISHED"}
    # end of execute(.)
# end of class OBJECT_OT_render_TR


class OBJECT_OT_playback_TR(bpy.types.Operator):
    bl_idname = "render.playback_timeremapper"
    bl_label = "Playback time remapped frames"
    bl_description = "Plays back frames, defining the start and end" \
                     " based on the time remapping"
    bl_register = True

    def execute(self, context):

        scene = context.scene

        print("Preparing playback")
        # get number of frames that we need to play back
        num_frames = len(get_TR_frames(context))

        old_frame_end = scene.frame_end

        scene.frame_end = scene.frame_start + num_frames - 1

        bpy.ops.render.play_rendered_anim()

        # restore the old end frame
        scene.frame_end = old_frame_end

        return {"FINISHED"}

# end of class OBJECT_OT_playback_TR


def draw(self, context):
    layout = self.layout

    scene = context.scene

    layout.label("Time Remapper:")

    row = layout.row(align=True)
    row.alignment = "LEFT"
    row.prop(scene, "timeremap_method")
    if scene.timeremap_method == "SF":
        row.prop(scene, "timeremap_speedfactor")
    elif scene.timeremap_method == "TTC":
        row.prop(scene, "timeremap_TTC")

    row = layout.row(align=True)
    rowsub = row.row(align=True)
    rowsub.operator("render.render_timeremapper",
                    text="TR Animation",
                    icon="RENDER_ANIMATION")
    rowsub.operator("render.playback_timeremapper",
                    text="TR Playback",
                    icon="PLAY")

    row = layout.row(align=True)
    row.alignment = "LEFT"
    rowsub = row.row(align=True)
    rowsub.label("Immune objects:")
    rowsub.prop_search(scene, "timeremap_immuneObject1", scene, "objects",
                       text="")
    rowsub.prop_search(scene, "timeremap_immuneObject2", scene, "objects",
                       text="")
    rowsub.prop_search(scene, "timeremap_immuneObject3", scene, "objects",
                       text="")


def find_fcurve(scene_or_obj, data_path, index=0):
    """Find a particular F-Curve."""
    anim_data = scene_or_obj.animation_data
    for fcurve in anim_data.action.fcurves:
        if fcurve.data_path == data_path and fcurve.array_index == index:
            return fcurve


def is_keyframed(scene_or_obj, data_path, index=0):
    """Check if the scene or object property is already keyframed
    Ideas from @CoDEmanX on Blender SE for this."""

    anim = scene_or_obj.animation_data

    if anim is not None and anim.action is not None:
        for fcurve in anim.action.fcurves:
            if fcurve.data_path == data_path and fcurve.array_index == index:
                return True
    return False


def using_immune_objects(context):
    """Check if the user has a valid immune object set, i.e. an object
    that will be immune to time remapping."""
    scene = context.scene

    for iobj_name in [scene.timeremap_immuneObject1,
                      scene.timeremap_immuneObject2,
                      scene.timeremap_immuneObject3]:
        if iobj_name != "":
            if iobj_name not in scene.objects.keys():
                print("WARNING: One of your selected immune objects ('" +
                      iobj_name + "') no longer corresponds to an object. "
                      "Did you change the name of that object?")
                continue
            else:
                return True

    return False


def keyframe_locrot_by_target_frame(obj, target_fr, frame):
    """Set the location and rotation of the object at frame to be same as
    values at target keyframe

    Return: if the object already had a keyframe there, then return a list of
    3-tuples, one 3-tuple for each keyframed property"""

    for data_path, tot_indices in [("location", 3), ("rotation_euler", 3),
                                   ("rotation_axis_angle", 4),
                                   ("rotation_quaternion", 4)]:
        # loop through index
        # (we loop 4 times for properties like Quaternion Rot.)
        for ind in range(tot_indices):
            if is_keyframed(obj, data_path=data_path, index=ind):
                fcurve = find_fcurve(obj, data_path, index=ind)
            else:
                continue

            # update the property to have value that it has at target frame
            props_to_update = getattr(obj, data_path)
            props_to_update[ind] = fcurve.evaluate(target_fr)
            setattr(obj, data_path, props_to_update)

            obj.keyframe_insert(data_path=data_path, index=ind, frame=frame)

    return


def delete_locrot_keyframes(obj, frame):
    """Delete all the location and rotation keyframes for object at given
    frame."""

    for data_path, tot_indices in [("location", 3), ("rotation_euler", 3),
                                   ("rotation_axis_angle", 4),
                                   ("rotation_quaternion", 4)]:
        # loop through index
        # (we loop 4 times for properties like Quaternion Rot.)
        for ind in range(tot_indices):
            if is_keyframed(obj, data_path=data_path, index=ind) is False:
                continue
            obj.keyframe_delete(data_path, ind, frame)

    return


def get_TR_frames(context):
    """Gets a list of time-remapped frames to be rendered"""

    scene = context.scene

    if scene.timeremap_method == "SF":
        TR_frames = get_TR_frames_from_SF(context)
    elif scene.timeremap_method == "TTC":
        TR_frames = get_TR_frames_from_TTC(context)
    else:
        assert False

    return TR_frames


def get_TR_frames_from_SF(context):
    """Gets a list of time-remapped frames to be rendered by
    looking at the Speed Factor parameter."""

    scene = context.scene

    # Time-remapped frames to render
    TR_frames = []

    # current time-remapped frame
    current_TR_frame = scene.frame_start

    # for unkeyframed, we can't use the F-Curve, so we treat it separately
    if is_keyframed(scene, "timeremap_speedfactor") is False:

        # avoid infinite loop by checing that speed factor's positive
        if scene.timeremap_speedfactor <= 0:
            raise RuntimeError("\n\nYou're speed factor must always be"
                               "positive to avoid getting stuck in an"
                               " infinite loop!")

        # loop through all frames until the end
        while current_TR_frame <= scene.frame_end:
            TR_frames.append(current_TR_frame)
            current_TR_frame += scene.timeremap_speedfactor

        return TR_frames
    # end of if block

    # speed factor's F-Curve
    SF_fcurve = find_fcurve(scene, "timeremap_speedfactor")
    assert SF_fcurve is not None

    # we loop through however many (time-remapped) frames it takes
    # to get to the end frame
    while current_TR_frame <= scene.frame_end:

        # add current frame to our list
        TR_frames.append(current_TR_frame)

        # get current speed factor
        current_SF = SF_fcurve.evaluate(current_TR_frame)

        # avoid infinite loop by checing that speed factor's positive
        if current_SF <= 0:
            raise RuntimeError("\n\nYou're speed factor must always be"
                               "positive to avoid getting stuck in an"
                               " infinite loop!")

        # move to next frame based on the current value of the speed factor
        current_TR_frame += current_SF
    # end while loop

    return TR_frames
# end of get_TR_frames_from_SF(.)


def get_TR_frames_from_TTC(context):
    """Gets a list of time-remapped frames to be rendered by
    looking at the Time Time Curve parameter."""

    scene = context.scene

    if is_keyframed(scene, "timeremap_TTC") is False:
        raise RuntimeError("the property timeremap_TTC must be keyframed"
                           "\nIt cannot be a constant value.")

    # Time-remapped frames to render
    TR_frames = []
    # jump to non-time-remapped start frame
    nonTR_frame = scene.frame_start
    scene.frame_set(nonTR_frame)

    # to avoid getting stuck in an infinite loop (ex: TT curve never reaches
    # the end frame), we break when we exceed max_frames.
    count = 0
    max_frames = 100000

    # TTC's F-Curve
    TTC_fcurve = find_fcurve(scene, "timeremap_TTC")
    assert TTC_fcurve is not None

    current_TTC_value = TTC_fcurve.evaluate(nonTR_frame)

    # we loop through however many (time-remapped) frames
    # it takes to get to the end frame
    while current_TTC_value <= scene.frame_end:

        TR_frames.append(current_TTC_value)

        nonTR_frame += 1
        current_TTC_value = TTC_fcurve.evaluate(nonTR_frame)

        count += 1
        if count >= max_frames:
            raise RuntimeError("\n\nHaven't reached end after counting 100 000"
                               "frames!\nMake sure the TT Curve value reaches"
                               " the end frame at some point.")
    # end of while loop

    return TR_frames
# end of get_TR_frames_from_TTC(.)


def update_TR_method(self, context):
    """Check if user switched to using a TT curve.  If so, and it is not
    keyframed, then keyframe it to produce a 45 degree angle curve (which
    corresponds to a one-to-one time mapping)

    Ideas from @pinkvertex on Blender SE."""

    scene = context.scene

    print("Inside update method")

    # if not switching to TT curve, or if it's already keyframed, return
    if scene.timeremap_method != "TTC" or is_keyframed(scene, "timeremap_TTC"):
        print("OK no need")
        return

    if not scene.animation_data:
        scene.animation_data_create()
    if not scene.animation_data.action:
        scene.animation_data.action = (bpy.data.actions
                                       .new("timeremap_TTC_action"))

    # find the correct f-curve in case there's multiple
    fcurve = scene.animation_data.action.fcurves.new("timeremap_TTC")
    # keyframe it to make a 45 degree straight line
    fcurve.extrapolation = "LINEAR"
    fcurve.keyframe_points.insert(frame=0.0, value=0.0)
    fcurve.keyframe_points.insert(frame=1.0, value=1.0)


def register():
    bpy.utils.register_module(__name__)

    bpy.types.Scene.timeremap_speedfactor = bpy.props.FloatProperty(
        name="Speed factor",
        options={"ANIMATABLE"},
        default=1.0
    )
    bpy.types.Scene.timeremap_TTC = bpy.props.FloatProperty(
        name="TT Curve",
        options={"ANIMATABLE"},
        default=0.0
    )
    bpy.types.Scene.timeremap_method = bpy.props.EnumProperty(
        name="",
        description="Method for defining the time remapping",
        items=[
            ("SF", "Speed Factor", "Use a speed factor "
             "(where 0.5 means 2x slow-mo)"),
            ("TTC", "Time-Time Curve",
             "Use a curve which shows how rendered frame maps"
             "to true-time frame")
            ],
        default="SF", update=update_TR_method
    )

    # We allow for 3 immune objects (of course, this could be increased)
    # I couldn't figure out how to get these into a collection and still use
    # the prop_search funciton while drawing panel.
    bpy.types.Scene.timeremap_immuneObject1 = bpy.props.StringProperty(
        name="Immune Object 1",
        description="Make object immune to time remapping effects"
    )
    bpy.types.Scene.timeremap_immuneObject2 = bpy.props.StringProperty(
        name="Immune Object 2",
        description="Make object immune to time remapping effects"
    )
    bpy.types.Scene.timeremap_immuneObject3 = bpy.props.StringProperty(
        name="Immune Object 3",
        description="Make object immune to time remapping effects"
    )

    # Draw panel under the header "Render" in Render tab of Properties window
    bpy.types.RENDER_PT_render.append(draw)


def unregister():

    del bpy.types.Scene.timeremap_speedfactor
    del bpy.types.Scene.timeremap_TTC
    del bpy.types.Scene.timeremap_method
    del bpy.types.Scene.timeremap_immuneObject1
    del bpy.types.Scene.timeremap_immuneObject2
    del bpy.types.Scene.timeremap_immuneObject3

    # remove the panel from the UI
    bpy.types.RENDER_PT_render.remove(draw)

    bpy.utils.unregister_module(__name__)


if __name__ == "__main__":
    register()