How do I set the reference frame in the Tracker?

I have run a Tracker. I want to set the reference frame. Can I set it after I have run the Tracker? Or do I set it before tracking the shot?

Thanks in advance.

Please give more detail in what you need to achieve. There are many ways to use tracking data.

Please give more detail in what you need to achieve. There are many ways to use tracking data.

I am using tracked data to match move a bullet hole over the forehead of an actor. I used Mocha Pro to generate the track, then copy-pasted the track data as a Tracker into Fusion.

Look for TrackerPlus in Reactor.

The Tool scripts contained in the tool can be run from any Tracker.

Look for TrackerPlus in Reactor.

Can I copy-paste keyframes from Mocha into TrackerPlus? If not, does TrackerPlus have a planar tracker mode?

Please give more detail in what you need to achieve. There are many ways to use tracking data.

I am using tracked data to match move a bullet hole over the forehead of an actor. I used Mocha Pro to generate the track, then copy-pasted the track data as a Tracker into Fusion.

Use a Merge for your foreground image. Link the Merge center to Tracker offset position. Use tracker x and y offset to fine tune the position.

Please give more detail in what you need to achieve. There are many ways to use tracking data.

I am using tracked data to match move a bullet hole over the forehead of an actor. I used Mocha Pro to generate the track, then copy-pasted the track data as a Tracker into Fusion.

Use a Merge for your foreground image. Link the Merge center to Tracker offset position. Use tracker x and y offset to fine tune the position.

I used Mocha's shape to track. Mocha created 4 trackers, which exist in one Tracker node when pasted. So, there are 4 Offset Position settings for the 4 trackers. I'm new to Fusion so I don't know how the nodes would be connected. Is the Tracker connected to the stream between the bullet hole and the Merge? What would the flow look like?

So you have 4 corner positioning. Just connect the foreground image to the green input on the tracker. In Operation tab choose corner positioning. The tracker will shape the image to follow the surface you have tracked in Mocha. Now you can also fine tune each of the corners to adjust the shape/perspective of the image.
Then feed the output of the tracker into a Merge, use the green foreground input. Connect the background image to the yellow input of the merge. The center of this Merge can also be used to offset and reposition the entire track.

That is the basic setup, you will probably need to mask the foreground, add any fx you like to the foreground. Do it before the tracker so any changes to the foreground image will be tracked.

In addition to the foreground image you can also track other elements later in the flow, such as a hotspot for example. Right click on the center position of the hotspot, Modify with Tracker, and you see a long list of different tracking data points, you will probably pick "Unsteady position".

Thanks, George. I appreciate the walkthrough.

Look for TrackerPlus in Reactor.

Can I copy-paste keyframes from Mocha into TrackerPlus? If not, does TrackerPlus have a planar tracker mode?

You don't need to use TrackerPlus itself--it comes with a tool script that you can run on any Tracker, including the one created by Mocha. I believe you have the tool installed already, so all you need to do is set your mocha Tracker to Select Time, right click the node and point to Script > UpdateReferenceFrame (or something like that, it may also be in a subfolder. I don't have TrackerPlus installed at the moment, and I don't remember the precise name). The reference frame will be updated to use the current frame.

Thanks, Bryan. I'll give that a go.

I've decided to redo the track with Fusions Tracker. There must be a step in the workflow that I'm missing, because I can't get it to simply track.

I scrub to the frame that I want to use as the time reference. I connect a Tracker to the footage and make sure its showing in Viewer 1. I align the tracker with a high contrast feature on the actor's nostril. As soon as I click to track, the tracker jumps to another area in the shot.

What am I missing here?

From the way you describe it, nothing. So there's probably a part that you're leaving out
Can you copy/paste the nodes in the 'code' boxes? Maybe that will help.

Code: Select all

{
   Tools = ordered() {
      Loader1 = Loader {
         Clips = {
            Clip {
               ID = "Clip1",
               Filename = "/Volumes/G-DRIVE USB-C/GENESIS/__VFX/78B-3_Blood/78B_tk03_4vfx.mov",
               FormatID = "QuickTimeMovies",
               Length = 406,
               Multiframe = true,
               TrimIn = 0,
               TrimOut = 405,
               ExtendFirst = 0,
               ExtendLast = 0,
               Loop = 1,
               AspectMode = 0,
               Depth = 0,
               TimeCode = 0,
               GlobalStart = 0,
               GlobalEnd = 405
            }
         },
         Inputs = {
            ["Gamut.SLogVersion"] = Input { Value = FuID { "SLog2" }, },
         },
         ViewInfo = OperatorInfo { Pos = { 350, 246 } },
      },
      Tracker1 = Tracker {
         Trackers = {
            {
               PatternTime = 150,
               PatternX = 0.315216368767639,
               PatternY = 0.530183946488294
            }
         },
         CtrlWZoom = false,
         Inputs = {
            Input = Input {
               SourceOp = "Loader1",
               Source = "Output",
            },
            Name1 = Input { Value = "Tracker 1", },
            PatternCenter1 = Input { Value = { 0.315216368767639, 0.530183946488294 }, },
         },
         ViewInfo = OperatorInfo { Pos = { 670, 124 } },
      },
      Saver1 = Saver {
         Inputs = {
            ProcessWhenBlendIs00 = Input { Value = 0, },
            Clip = Input {
               Value = Clip {
                  Filename = "/Volumes/G-DRIVE USB-C/GENESIS/__VFX/78B-3_Blood/_Renders/78B_tk03_vfx_v01.mov",
                  FormatID = "QuickTimeMovies",
                  Length = 0,
                  Multiframe = true,
                  Saving = true,
                  TrimIn = 0,
                  ExtendFirst = 0,
                  ExtendLast = 0,
                  Loop = 1,
                  AspectMode = 0,
                  Depth = 0,
                  TimeCode = 0,
                  GlobalStart = -2000000000,
                  GlobalEnd = 0
               },
            },
            OutputFormat = Input { Value = FuID { "QuickTimeMovies" }, },
            ["Gamut.SLogVersion"] = Input { Value = FuID { "SLog2" }, },
            Input = Input {
               SourceOp = "Loader1",
               Source = "Output",
            },
            ["QuickTimeMovies.Compression"] = Input { Value = FuID { "H.264_avc1" }, },
         },
         ViewInfo = OperatorInfo { Pos = { 1535, 245 } },
      }
   }
}

I got the track to work. However, for some reason, the tracked element is offset every other frame. I couldn't paste the code, because it exceeded 60,000 characters - probably because of the track.

Here is the node layout:

Do you see the area you are tracking in the Inspector before you start tracking? In the area I am pointing to in the attached image.

Do you see the area you are tracking in the Inspector before you start tracking? In the area I am pointing to in the attached image.

Yep. I am able to get to track. But, why would the element be offset every other frame?

Could you try connecting something like a Text+ node with some sample text to see how it follows along? Can you elaborate on what you mean by offset every other frame? Is it lagging behind, is it jumping around?

It jumps to the left every other frame. On one frame its where it should be, the next frame its offset to the left by about 100 pixels, then the next frame its back where it should be, then the next frame it's offset to the left again. I don't know why it would do that. The track itself seems fine.

I'll attach a Text node and see what happens.

Maybe try messing with the search area for the tracker or maybe the Adaptive Mode.

It seems that the problem was with the Polygon mask I used on the element. I just opened the element in Affinity Photo (a Photoshop type app), and erased the area I was masking out with the Polygon shape. I reimported the new version into Fusion and attached it to the track- without the Polygon mask - and it follows the track.

It seems the Polygon shape was causing the problem. Maybe I should use the Polygon shape on the Merge? I don't know. What do you think?

It seems that the problem was with the Polygon mask I used on the element. I just opened the element in Affinity Photo (a Photoshop type app), and erased the area I was masking out with the Polygon shape. I reimported the new version into Fusion and attached it to the track- without the Polygon mask - and it follows the track.

It seems the Polygon shape was causing the problem. Maybe I should use the Polygon shape on the Merge? I don't know. What do you think?

I've used polygon masks with tracking elements before and haven't had an issue, I don't know why it caused an issue in your case.

I don't know either. I'm new to Fusion, so I'm still getting used to the workflow. Maybe if I attached the mask to the Tracker node itself? Would that make a difference?

What do you need the mask for?
I don't know if this is the case here, but maybe the mask in some way messes with the resolution or ROI or DOD (I can never tell those apart) so the image flips back and forth. Also: if you do the tracking without having anything attached to the FG input, does it still do that?

What do you need the mask for?
I don't know if this is the case here, but maybe the mask in some way messes with the resolution or ROI or DOD (I can never tell those apart) so the image flips back and forth. Also: if you do the tracking without having anything attached to the FG input, does it still do that?

Once I removed the mask, after cleaning up the edges, it stopped jumping around. Unfortunately, the overall track is still erratic. The shot was filmed on a gimbal, where I walk from 10 feet away up to about 2 feet away. That distance may be too dramatic for the tracker. I also tried a Planar Tracker, and that still wasn't good enough. I'm trying to get the director to reshoot it, and just use simple makeup on the actors.

Well, you do know where to find me off-forum, so I can offer you some more precise tips/tricks.

Well, you do know where to find me off-forum, so I can offer you some more precise tips/tricks.

Will do.