Twixtor Combustion Examples.

NOTE: You need Twixtor 4.0 for these examples. You also need Combustion 3.0 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.

Before opening the project examples, make sure to move the movies from the SourceMovies folder into this folder (make sure the movies are in the same directory with the combustion projects, otherwise combustion will not find them).

1_Make4xInDuration

Shows you how to take footage and make the footage four times as long. Note that in the Footage settings for the clip 'catcrop' that the "Output->End Behavior" has been set to "Hold." This is done because Twixtor is not allowed to make a clip longer and the "Hold" end behavior accomplishes that. Also note that the Color Source is set to the footage we wish to stretch.

In the comp settings for "Slow Mo 4x Interlaced" we've set combustion's Fields setting to Lower First. In this comp Twixtor's interpolation methods to create each field. To view both fields set combustion's Window->Field Mode is set to Both Fields. In the comp "Slow Mo 4x Progressive" we've set combustion's Fields setting to None. For this comp Twixtor will create progressive footage.

Pre-Twixtor 4 users: note that combustions's Footage Controls->Source->Field Separation for the source footage is set as appropriate and not to "None" as required in previous versions of Twixtor. Similarly, instead of setting the output field setting inside of Twixtor, you now do that with combustions composite controls settings and, when rendering to disk, via the combustion's render settings.

2_KeyframeRamp

This sample project shows how you might keyframe the time remapping for a more dynamic effect. Note that in the comp DynamicRemapSpeed that the Time Remap Mode setting is set to Speed and we animate the Speed% setting. In the comp DynamicRemapFrame note that the Time Remap Mode setting is sett to Frame Number and that the FrameNum setting has been animated.

3_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 comp ProblemShown 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 comp MarkSegments you'll see that we've marked the start of the first cut by setting Twixtor's Src: Mark Segments to Cut A. Then we've animated the Src: 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. Retimed output frames created from dissolve transition can be created this way by setting Src: Mark Segments to No MV: Frame Blend.

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

4_30iTo24p

This is a sample project that demonstrates how to convert interlaced video to film (whole frame, 24fps). Notice otice that the composite is at 24fps and the footage is at 29.97fps.

5_TrackingProblem

This sample project shows how you might provide keyframes for the Motion Vectors parameter when there problematic frames for Twixtor. We apply Twixtor to a sequence and time stretch it by a factor of 3. In "Problem Shown" 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 comp "Key Motion Vector Quality":The sequence starts with Motion Vectors set to Best, but there is a section where the hand comes across the face that is problematic for Twixtor. We have set Motion Vectors 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 Motion Vectors back to Best when the problematic area is exited.
2. In the comp "Lower Motion Sensitivity": 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).

6_SmartBlend

This sample project shows the difference of using Smart Blend on a sequence with significant movement at the edges of a moving sequence. With 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 Smart Blend on when there is significant motion at the edge of the frame.

Twixtor PRO examples

7_LayersExample

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

8_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 composition "Problem Shown" exhibits what happens with regular Twixtor with no layer separation. Note that objects passing each other tend to gloop against each other.

The composition "Multiple Layers 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.

9_TrackPointExample

This sample project show how, with Twixtor Pro, you can get better results by guiding Twixtor the use of a few judicial Track Points.

The composition "Problem Shown" exhibits what happens with regular Twixtor with manual tracking help. Note that the object on the left is ghosted in the Twixtored result.

The composition "Twixtor Pro w Tracking Pts" shows how you can guide Twixtor. in this case with 3 tracking points.

For you to do and notice:

- Note that the Use menu for for Track Points 1, 2 and 3 have been set to "Main_BG"
- Note that the ghosting has been removed
- To see the Twixtor's track points, set Display to Source. When in this mode you can see that Twixtor draws all of the points being used. Make sure to animate Track Points when Display is set to Source.
- 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 helped with tracking guidance, we've set the Motion Sensitivities to 100.

10_TrackPointsAndLayerExample

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

The composition "Problem Shown" exhibits what happens with regular Twixtor with no layer separation. Note that the result is very unsatisfactory.

The composition "Twixtor Pro w Tracking Pts" shows how you can guide Twixtor. in this case with 1 tracking point per layer.

For you to do and notice:

- Note that the Use menu for for Track Point 1 is set to "FG1"
- Note that the Use menu for for Track Points 2 and 3 is set to "Main_BG"
- Note that the "glooping" has been removed
- To see (or animate) the Twixtor's track points, set Display to Source. When in this mode you can see that Twixtor draws the mask 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.
- Is really important is to note the track point guiding the background: it guides the background movement while the foreground obscures it (particularly note where the track point is for the second source frame of the sequence). thus guiding the motion estimator through motion that is hidden.
- Note that the FG1 Inv Matte Choke has been set to 1. 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

11_SplineGuidanceExample

You will need Combustion 3 or later this example.

This sample project show how, with Twixtor Pro, you can get better results by guiding Twixtor the use of a Combustion's splines.

The composition "Problem Shown" exhibits what happens with regular Twixtor is not supplied manual tracking help. Note that the result is very unsatisfactory.

The composition "Twixtor Pro with Spline Guides" shows how you can guide Twixtor. in this case with combustion's roto splines

For you to do and notice:

- Note that the tracking has been greatly improved.
- o 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.

12_SplineAndMaskGuidance

You will need Combustion 3 or later this example.

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

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

For you to do and notice in the comp named "Twixtor Pro with Spline Guides":

- Note that it is advisable to set Combustion to calculate frames at Half resolution (that is, "Medium" is recommended for Combustion's quality setting).. 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.
- 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.
- Note that for each spline has been assigned to a particular layer by setting the "Layer" setting for each spline.
- Note that by default, when the spline is created that the spline, by default, is used to help guide Twixtor because the Use parameter is, by default, set to On.
- Not all splines are used at all frame times to help guide Twixtor. Note that the Use setting for each spline is keyframed to Off when not used at a particular source time. When not used to help guide the tracking, the splines are often moved off the image.
- Remember, to be helpful in guiding Twixtor, you must animate the spline (and have it active via the Use setting) on at least two source frames.
- Note that the Use setting should be animated when in "source time," that is, when Display is set to Source.
- To see what Twixtor is using to guide the tracking, set Display to Source. Note that Twixtor does not draw the masks unless they are active (via the Use setting) AND the Display menu is set to Source.
- Is really important is to note that the splines used for guidance often show Twixtor where objects move as they are obscured or move on/off screen.

13_MotionVectorsIn

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

13a_RetimeUsingVectors

This comp 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 project is set to work in 16bpc.

13b_RetimeLayersUsingVectors

In this case motion was calculated for the two objects (hand and face) independently. The comp labeled "Problem Shown" shows the tearing and smearing that can happen if you don't also provde the Twixtor Pro, Vectors In plugin 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.

Copyright 2000-2005 RE:Vision Effects, Inc.