Twixtor Digital Fusion Examples.

NOTE: You need Twixtor 4.5 for these examples. You also need Digital Fusion 4.04e or later or Fusion 5.01 or later.

This directory contains several projects to help explain features of Twixtor.

Important: These tutorials assume you have read the manual that was put on your disk with the plugin upon installation.

1_Make4xInDuration

This sample project show you how to take footage, with fields, and make the footage four times as long. Twixtor is not allowed to make a clip longer so note that the input loader has been set up so that the last frame of the sequence is extended. The original clip is 30 frames long, so the the Hold Last Frame for the loader has been set to 90, so the entire clip will appear 120 frames to Twixtor, which is our desired final duration.

The Speed has been set to 25%, so the Twixtored footage will play at 1/4 the speed of the original.

In the node labeled "Twixtor4InterlacedOut", the Process Mode in the Output Controls Format tab has been set to the default of Auto. Since the input is interlaced the output is interlaced.

In the node labeled "Twixtor4ProgressiveOut", the Process Momde in the Output Controls Format tab has been set to Full Frames. So Twixtor slows down the footage and converts to progressive frames for the output sequence.

2_KeyFrameRemap

This sample project shows how you might keyframe the time remapping for a more dynamic effect. Note that in the node Twixtor4RemapSpeed that the Retime Method setting is set to Speed and we animate the Speed setting. In the node Twixtor4RemapFrame note that the Retime Method setting is set to Frame and that the Frame setting has been animated.

3_TrackingProblem

This sample project shows how you might provide keyframes for the Tracking Quality parameter when there problematic frames for Twixtor. We apply Twixtor to a sequence and time stretch it by a factor of 3. In "Twixtor4ProblemShown" you can see that the hand coming across the face drags around parts of the face that shouldn't be warped. Also, the hand is not tracked properly because of the face behind it and inappropriately stutters upon retiming. So we demonstrate how to fix the problem using 2 different methods:

1. In the node "Twixtor4KeyMotionVecto Quality":The sequence starts with Tracking Quality set to Best, but there is a section where the hand comes across the face that is problematic for Twixtor. We have animated Tracking Quality setting and set it to No Motion Vectors for the problematic area, keeping Frame Interp set to Blend. This effectively turns off motion tracking and warping and produces results that defaults to simple frame blending (just like AE does by default). We set Tracking Quality back to Best when the problematic area is exited.
2. In the node "Twixtor4LowerMotionSensitivity": Instead of explicitly turning off the motion estimation as we did in example 1, we adjust it down by setting Motion Sensitivity to 20 (down from 70). This reduces the amount of movement each pixel can make (and it's influence on surrounding pixels), effectively eliminating the "gloop" (however, the background face and head does not track nearly as well).

4_SmartBlend

This sample project shows the difference of using the Warping setting of Inverse W/Smart Blend (instead of just Inverse) on a sequence with significant movement at the edges of a moving sequence. With Inverse W/Smart Blend turned off we see significant smearing at the edges when one of the frames is warped to match the other. With Smart Blend turned on we see this problem disappear.

Rule of thumb: turn Warping to Inverse W/Smart Blend on when there is significant motion at the edge of the frame. You can try setting Warping to Forward if you are doing a slowmotion of speed less than 50% and you see significant sliding.

5_WorkingWithEdits

This sample project has a piece of footage that is being slowed down by a factor of 5. Note that there is a hard cut in the source footage and a dissolve transition. In the node "Twixtor4ProblemShown" you can see the problem of interpolating between the frames of the hard cut. You can also see tracking problems in the retiming of the dissolve (you can see flickering movement that shouldn't occur). It's "obvious" that these transitions should be marked so that Twixtor does not interpolate inappropriately across the transitions.

In the node "Twixtor4MarkSegments", switch the Display setting to Source. You'll see that the Mark Segments setting now appears.

In the node Mark Segments you'll see that we've marked the start of the first cut by setting Twixtor's Mark Segments to Cut A. Then we've animated the Mark Segments menu setting and set it to Cut B at the start of the cut between the first and second segments. No motion interpolation or color blending between frames is used when Twixtor creates a retimed output frame that is between Cut A and Cut B. For the dissolve transition we'd like Twixtor to create dissolved (blended color) inbetween frames, but with no motion interpolation (many times when working on a dissolve or other transition in the source footage, the tracking within Twixor can behave poorly). Retimed output frames created from dissolve transition can be created this way by setting Mark Segments to No MV: Frame Blend.

Note: To reinforce that Mark Segments should be set and animated in the original timing of the clip being retimed, Mark Segments can only be set when Twixtor's Display setting is set to Source.

NOTE: If you decide to animate the settings for Mark Segments (or any menu in Fusion), you should make sure to set the animation settings for all the keys to "Step In" and "Step Out", using Fusion's spline editor for animated settings, so that you don't inadvertantly get unwanted "inbetween" menu settings over the course of the animation.

6_LayersExample

This sample project shows how, with Twixtor, you can use a matte to separate foreground and background for even better results when an object in front passes other objects.

Digital Fusion 4 users take note: it is not obvious by looking at the flow, but in the node "Twixtor4FGMaskUsed" the LayersFGMask clip has been connected to the TwixtorFG1Matte input mask setting that can be reached by right-clicking on the image in the viewer when the Twixtor node is selected (see the manual). This connection was accomplished by right-clicking in the viewer when the Twixtor node was selected and selecting "Bitmap" from the TwixtorFG1Matte submenu.Also note that the connected clip's controls show up in the Masks tab for Twixtor.

Fusion 5 users: it should be obvious that the LayersFGMask clip has been connected to the TwixtorFG1Matte input mask. This was done by right-clicking in the viewer when the Twixtor node was selected and selecting "Bitmap" from the TwixtorFG1Matte submenu.

7_ThreeLayersExample

This sample project shows how, with Twixtor Pro, you can use multiple layer mattes to separate several foreground elements for even better results when an objects pass over each other.

The node "No FG Mattes" exhibits what happens with regular Twixtor with no layer separation. Note that objects passing each other tend to gloop against each other.

The node "2 FG Mattes Used" with Twixtor" exhibits how a better result can be obtained by supplying mattes for the two foreground objects.

For you to do and notice:

- Because we've separated the footage into layers, we get better results by expanding the default motion sensitivites of the layers from 70 to 100 (which lets the motion estimator search for greater movement).
- Switch the Display setting to FG1 Twixtored or FG2 Twixtored or BG Twixtored to see each layer Twixtored by itself.
- Note that the matte for FG2 is created for the whole object (the cat head) whether or not it is obscured, and not just for the part that is visible.

8_MotionVectorsIn

This example shows how to use motion vectors as input to retime a sequence using input vectors to the Twixtor plugin.

8MotionVectorsIn1

1) Retime Using Vectors

This flow shows how to hook up the Prev and Next motion vectors (that is, motion vetors from the current frame to the previous frame and motion vectors from the current frame to the next frame, respectively). Note that the Vector images are 16bpc.

8MotionVectorsIn2

2) Retime Layers Using Vectors.

In this case motion was calculated for the two objects (hand and face) independently. The node labeled "Problem Shown" shows the tearing and smearing that can happen if you don't also provide Twixtor with a matte that shows where the foreground object is. "Layers Correct Usage" shows the improved results by supplying the plugin a foreground matte that delineates where the foreground object is at each frame.

The rest of the examples are only applicable for Fusion 5.01 or later.

9_SplineGuidanceExample.comp

This sample project show how, with Twixtor, you can get better results by guiding Twixtor with Fusion's splines.

The node "TwixtorProblemShown" exhibits what happens with regular Twixtor is not supplied manual tracking help. Note that the result is very unsatisfactory (especially at the second frame).

The node "TwixtorWithSplines" shows how you can guide Twixtor with Fusion's splines.

For you to do and notice:

- Note that the tracking has been greatly improved.
- The splines have been animated to follow the salient features.
- To see the splines Twixtor is using to help guide the tracking, set Display to Source. When in this mode you can see that Twixtor draws all of the splines being used.
- Note that we've changed the Warping setting to Forward. We've done this because we've added tracking guidance, and Twixtor's retiming generally works better with this setting when tracking guidances has been given.
- Because we've separated the image into layers, and because we've helped with tracking guidance, we've set all layers' Motion Sensitivities to 100.
- The splines' "Layer" setting is set to Main_BG (this is the default).
- The splines' "Use" setting is set to ON (this is the default)

10_SplinesAndLayers.comp

This sample project show how, with Twixtor, you can get better results by guiding Twixtor with the use of a few judicial splines used in tandem with Twixtor's layer separation feature.

The node "TwixtorProblemShown" exhibits what happens with Twixtor with layer separation, but no spline guidance . Note that the result is very unsatisfactory.

The node "TwixtorSplinesAndLayers" shows how you can guide Twixtor in this case with 1 spline per layer.

For you to do and notice:

- Note that the Use menu for the spline "FG1_CenterOfEye" is set to "FG1"
- Note that the Use menu for the spline "BG_EyesAndEars" is set to "Main_BG"
- Note that the "glooping" has been removed
- To see (or animate) the Twixtor's splines, set Display to Source. When in this mode you can see that Twixtor draws the splines being used to guide Twixtor.
- Note that we've changed the Warping setting to Forward. We've done this because we've added tracking guidance, and Twixtor's retiming generally works better with this setting when tracking guidances has been given.
- Because we've separated the image into layers, and because we've helped with tracking guidance, we've set all layers' Motion Sensitivities to 100.
- It is really important to note the spline guiding the background: it guides the background movement while the foreground obscures it (particularly note where the spline is for the second source frame of the sequence) thus guiding the motion estimator though the motion is hidden.
- Note that the FG1 Inv Matte Choke has been set to 1 (in the Foreground Layers tab). Set it to 0 and RAM preview the sequence; notice when set to 0 that a ring of the foreground is left on the background as it is Twixtored.

11_MoreSplinesAndLayers.comp

This example shows a very complex example with 4 layers (3 foreground mattes supplied) and several splines, used on several layers, to guide Twixtor's tracking.

The node "Problem Shown" exhibits what happens with Twixtor, even with layer separation. Note that the result is very unsatisfactory.

For you to do and notice in the node named "TwixtorSplinesAndLayers":

- Note that Fusion has been set to calculate frames at Half resolution. This is so you can easily navigate the project. After you've explored the project and its settings, you might want to turn this to Full to see how much better the results are.
- To see (or animate) the Twixtor's splines, set Display to Source. When in this mode you can see that Twixtor draws the splines being used to guide Twixtor.Note that the "glooping" has been removed
- Note that we've changed the Warping setting to Forward. We've done this because we've added tracking guidance, and Twixtor's retiming generally works better with this setting when tracking guidances has been given.
- Because we've separated the image into layers, and because we've helped with tracking guidance, we've set all layers' Motion Sensitivities to 100.
- Not all rotosplines are used at all frame times to help guide Twixtor. Note that we move the rotosplines off the image when not needed. To see when a spline is used, you can set the Display mode to Source and then turn on DrawGeom. When a spline is drawn, it is being used.
- Note that each spline is assigned to its appropriate separation layer.
- So that splines moved from off image to on image don't adversely affect the tracking, we animate Twixtor's Use setting to OFF for each rotospline when a spline not meant to be used (that is, when off the image) and ON when it should be used. Remember, to be helpful in guiding Twixtor, you must animate the rotospline (and have it active) on at least two source frames.
- It is really important to note that the splines used for guidance show Twixtor where objects move as they are obscured or as they move on/off screen.

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