Recently I have been continuing to experiment with the frame interpolation and warping capabilities of Reelsmart Twixtor and the TimeWarp and Optical Flow plugin for After Effects 7.0, in order to create smoother motion for 3d animation.
Frame interpolation refers to the process of creating new frames by analyzing existing frames. This is usually necessary when speeding up or slowing down footage. In such programs as Final Cut Pro and Premiere Pro (and After Effects sometimes), this interpolation is often accomplished by Frame-Blending, especially when slowing down footage. Frame-Blending essentially means to take two adjacent frames and combine them by making both transparent. This usually results in the ghosts of objects showing up in the frame, especially fast moving objects. This can appear quite strange or distracting to my eye.
Twixtor uses a combination of frame-blending, warping, and motion blur to calculate new interpolated frames. The warping capabilities, if executed carefully, results in much smoother natural looking motion when slowing down footage. This natural-looking motion is useful to the animation experiments I have been doing.
Most stop-motion animation is performed at 12 or 15 frames per second, depending on the end frame-rate of the format. For example, if the final output was going to be 24fps, as my project will be, one would animate at 12, meaning that there would be 12 frames passing in one second. In order to “upconvert” the frame-rate to the destination format, each frame must be repeated twice (24=2*12). Having each frame play twice results in motion that looks much more jerky than normal live-action. Frame-Blending can help slightly to smooth this out, but it doesn’t look very good. Here is where Twixtor comes into play. If you import an image sequence of an animation into After Effects with an interpreted frame rate of 24 (meaning that each frame of the original animation is one frame, and our animation is playing double-speed), and then apply the Twixtor plugin the composition, slowing it down by a factor of 2, the motion is smoothed out considerably. (this is the video from the test animation in the 3D labs that I did with Brad).
Of course, one must carefully adjust the settings of the plugin to avoid artifacts of the image warping, as I have discovered in my tedious experimention. If there is a great deal of motion between frames, the warping and blending can really get out of hand. This is a crazy little animation with clay and a frenetically moving background.
Clay Leg Man, original 12fps:
[flv:http://www.archive.org/download/Crotch_Launch_Animation__2_1/claymanregularmotion.mov 360 240]
Clay Leg Man, Twixtorized:
[flv:http://www.archive.org/download/Clay_Leg_Man/ClayLegManTwixtorized.mov 360 240]
These videos, which require the new quicktime plugin version of the Adobe Flash Player, and which in my estimation are of a great deal better quality than youtube, were made possible by the free Creative Commons media storage available at ourmedia.org, and the greatness ofarchive.org.
This is all very interesting, but I really must work on my soundtrack now.
Recently I have been continuing to experiment with the frame interpolation and warping capabilities of Reelsmart Twixtor and the TimeWarp and Optical Flow plugin for After Effects 7.0, in order to create smoother motion for 3d animation.
Frame interpolation refers to the process of creating new frames by analyzing existing frames. This is usually necessary when speeding up or slowing down footage. In such programs as Final Cut Pro and Premiere Pro (and After Effects sometimes), this interpolation is often accomplished by Frame-Blending, especially when slowing down footage. Frame-Blending essentially means to take two adjacent frames and combine them by making both transparent. This usually results in the ghosts of objects showing up in the frame, especially fast moving objects. This can appear quite strange or distracting to my eye.
Twixtor uses a combination of frame-blending, warping, and motion blur to calculate new interpolated frames. The warping capabilities, if executed carefully, results in much smoother natural looking motion when slowing down footage. This natural-looking motion is useful to the animation experiments I have been doing.
Most stop-motion animation is performed at 12 or 15 frames per second, depending on the end frame-rate of the format. For example, if the final output was going to be 24fps, as my project will be, one would animate at 12, meaning that there would be 12 frames passing in one second. In order to “upconvert” the frame-rate to the destination format, each frame must be repeated twice (24=2*12). Having each frame play twice results in motion that looks much more jerky than normal live-action. Frame-Blending can help slightly to smooth this out, but it doesn’t look very good. Here is where Twixtor comes into play. If you import an image sequence of an animation into After Effects with an interpreted frame rate of 24 (meaning that each frame of the original animation is one frame, and our animation is playing double-speed), and then apply the Twixtor plugin the composition, slowing it down by a factor of 2, the motion is smoothed out considerably. (this is the video from the test animation in the 3D labs that I did with Brad).
Crautch Lunch, Original:
[flv:http://www.archive.org/download/Crotch_Launch_animation_test_2/crotchlaunchseqregular.mov 360 240]
Crautch Lunch, Twixtorized:
[flv:http://www.archive.org/download/Crotch_Launch_Animation__2/crotchlaunchseqtwixtorized.mov 360 240]
Of course, one must carefully adjust the settings of the plugin to avoid artifacts of the image warping, as I have discovered in my tedious experimention. If there is a great deal of motion between frames, the warping and blending can really get out of hand. This is a crazy little animation with clay and a frenetically moving background.
Clay Leg Man, original 12fps:
[flv:http://www.archive.org/download/Crotch_Launch_Animation__2_1/claymanregularmotion.mov 360 240]
Clay Leg Man, Twixtorized:
[flv:http://www.archive.org/download/Clay_Leg_Man/ClayLegManTwixtorized.mov 360 240]
These videos, which require the new quicktime plugin version of the Adobe Flash Player, and which in my estimation are of a great deal better quality than youtube, were made possible by the free Creative Commons media storage available at ourmedia.org, and the greatness of archive.org.
This is all very interesting, but I really must work on my soundtrack now.