Best way of filming and multicam editing a rc car race

lyhne Posts: 14 Just Starting Out*
edited July 2021 in Practical Filmmaking

Hi all,

I want to film a rc race, like how you see it in tv like F1 race. So my idea is to do like this:

Place as many fixed cameras as possible around the track. Then I will switch from camera to camera when editing, to follow the cars around the track. The challenge is to keep track of using the right pass-by from each camera so that I don’t mess up by clipping using the wrong clips.

My idea to fix that is like this: Use a signal horn to sync videos. Then I can place each camera clip in its own track in the editor in hit film and move the clips on the timeline until the horn signal is perfect synced.

When clipping the final video can I somehow in hitfilm in an easy way choose track 1 from this time to this time, then track 2 next couple of seconds , then track 3 next couple of seconds and so on.

Is that the easiest way to make the movie, or is there a better technique?


  • DafterThings
    DafterThings Posts: 985 Enthusiast

    That's pretty much what I would do.

    Start all the cameras, make a noise picked up by all camera mics (I think this is what a clapperboard is for?), run the race and then stop all the cameras. Take all the footage into a comp shot, sync them up using the sound and then simply use the cut tool to select the parts of each video. They should all be in time order anyway (once synced).

  • Triem23
    Triem23 Posts: 20,275 Power User

    Yeah, that's pretty much your option.

    What you're setting up is a "multicam edit." Some software, like Vegas Pro or FCPX, have dedicated multicam modes. Unfortunately, Hitfilm doesn't, so your editing will be a little tedious.

    For purposes of discussion, let's say you have four cameras. This means you'll want FIVE tracks in the Editor - one for each camera and your "Master." You'll want to sync your cams on the Timeline first (using Trimmer to Editor workflow is the wrong way to approach a multicam. It'll just suck).

    Use the color swatches to assign each track a different display color.

    On your first pass you'll be stepping through the videos, slicing out the in/out points for desired clips per camera then moving them to the Master Track. After this pass save the project, then save again under a new name. Then you can delete the camera tracks (if desired) and just refine your Master. There are editors I know who actually prefer this workflow to the dedicated multicam modes in their editing software.

    Unfortunately Hitfilm doesn't have an easy way to solo a single track. Once you have everything synced up consider duplicating one camera track in the Editor, right clicking and making a Comp from this track. Resynch your other cameras and use Split screen masking (if you have that add on) or using position/scale to make a multiview display with every camera visible at once. If you've color coded your tracks in the Editor, then maybe use instances of lightning or small planes to add a little color line to each camera matching its track color.

    Render this comp. Import the render and put it on the top track (mute the others, you won't need to see them yet for your first pass). You can use the multiview as your reference so you don't have to keep turning tracks off and on to check each camera. With the color reference you'll know if your green camera is what you want to see right now you slice the green track! Rendering the multiview will take time, but it'll make the editing go faster. Better to render your multiview overnight and walk away from the computer than spend extra time muting/unmuting tracks to check your cameras.

    Incidentally, the multicam modes in other software basically auto-create the multiview for you, so the workflow described here is pretty standard. You just have to build your own multiview.

  • iamkhanproductions
    iamkhanproductions Posts: 596 Enthusiast

    Go Pro Cameras, Lots of Go Pro cameras..

  • lyhne
    lyhne Posts: 14 Just Starting Out*
    Okay, that's a little more complicated than I hoped for. I hoped there were a easy way of marking which track (=camera) was being used by somehow put markers in the editor. I haven't filmed it yet but I will soon do so and try your proposals.
  • lyhne
    lyhne Posts: 14 Just Starting Out*
    There is a 90day trial for FCPX but unfortunately it's for Mac only, I have a Win10 PC. But there are a 30day trial for Vegas Pro, maybe I should try that out
  • lyhne
    lyhne Posts: 14 Just Starting Out*
    Now that I know this technique is called "MultiCam edit" I could search better and found this video: it looks pretty easy but I don't understand why he makes copies of the tracks?

    @Triem23 I understand the first part you mention:
    "On your first pass you'll be stepping through the videos, slicing out the in/out points for desired clips per camera then moving them to the Master Track. After this pass save the project, then save again under a new name. Then you can delete the camera tracks (if desired) and just refine your Master. There are editors I know who actually prefer this workflow to the dedicated multicam modes in their editing software. "

    But I don't quite follow the last part. Why is that needed?
  • Triem23
    Triem23 Posts: 20,275 Power User
    edited July 2021

    Vegas Pro does have a dedicated multicam mode.

    Oh, saving the project again under a different file name is, in general, smart practice. A tv show or film editor will literally use an updated file name every time they save.

    First, if you "over edit" and decide you liked yesterday's cut better, it's there. Second, if a file corrupts - and it can happen - you'll be glad to have the backup.

    In this specific case I suggested deleting all the original sync tracks and just refining the master edit you've made. But keeping a backup of the multicam sync is just smart so it's there if needed.

    Edit: I haven't watched the cromthor video yet. I'll get back to you on that.

  • lyhne
    lyhne Posts: 14 Just Starting Out*

    Ok, that makes sense, thanks for pointing that out :-)

  • alaska_vfx_filmer
    alaska_vfx_filmer AlaskaPosts: 556 Enthusiast

    Davinci resolve does multicam almost as good as fcpx, and its free

  • Triem23
    Triem23 Posts: 20,275 Power User

    @lyhne Now that I've watched the video you linked, I can comment on it.

    Above I suggested making one track for each camera clip and one "master" track for your edit. I also suggested precomping a copy of all your cameras and either using the Split Screen Masking add on or scale/position keyframes to create a picture in picture of all your angles and rendering that out. Bring in the multicam render, and hide the individual tracks. I suggested then watching the multicam render, slicing the individual cameras where desired then moving each slice into the master track.

    These recommendations were made because I don't know how many camera angles you have, or how powerful your computer is. Hitfilm (and other NLEs) are pretty brute force - which means they have to look at everything that's active on a Timeline - *even if the layer/track is currently empty - to calculate and render the current frame. By rendering out a multicam window and muting all the sync tracks on your Timeline Hitfilm is only playing two tracks - the multicam and the master. This reduces resources so Hitfilm can play back more smoothly.

    In particular, I suggested moving cut clips up to a single master because this puts all the edits on one track and leaves gaps in the sync tracks where I can see footage has been used. This is how my brain organizes data.

    In the cromthor video he's doing the same basic concept, with a different organization.

    Cromthor has set up his "multicam" directly in the Editor Timeline. By re-scaling footage directly. Cromthor has duplicated all his footage and is "cutting holes" in the top tracks. Where a top track has no footage you see through to the footage underneath. I've done this, but I ended up preferring moving all my cuts to a single track. In cromthor's workflow refining the edit means he's got to mess around dragging clip edges on two tracks. My scheme refines the edit on a single track. Both are "correct." It just depends on what makes more sense to you. His method reduces setup time, but he's got - in this example - six tracks playing while my version has two. If you have, say, 8 or 10 cameras going (not unreasonable for a RC track) that's 16 or 20 tracks playing at once. That's going to cause lag. My method has two tracks playing - period.

    And now to actually answer your question. Cromthor duplicated his tracks because he's leaving a "reference" copy intact. That way he can always see a full copy of all his sources. If he had been cutting his "input" tracks, they'd all gap. While he didn't show this step, after he resized his "Output" tracks to fill the screen, he would have deleted his "input" tracks. He doesn't need them anymore.

    You do NOT have to duplicate the "input" tracks to create an "output" track. You could just directly slice the "input" tracks then resize those at the end, but, if you slice the input tracks you can't see footage that's just been trimmed. Directly cutting the input tracks is a "correct" workflow as well. Again, it depends on what makes most sense to you.

    Cromthor's method is actually pretty clever. Depending on how many cameras I had I'd probably incorporate one of his tricks into my method:

    I'd still pre-process my individual cameras in a Comp Shot and render - in the Editor Timeline this will still make things smoother - but try and leave an extra large area for my "output" window. In my Editor Timeline I'd select all my camera tracks and shrink them to fit the output window zone. Then I'd mute my camera tracks. I'd put my multicam render at the bottom, all my muted camera tracks above that, then my (visible) single master/output track at the top. As I sliced sections from the camera tracks and moved them to the master track I'd be able to see my cuts taking shape. After the first pass, resave under a new name, delete my camera and multicam tracks then select all the clips in the master and Fit to Frame like Cromthor's workflow.

  • lyhne
    lyhne Posts: 14 Just Starting Out*

    @Triem23 Thanks a lot for all your input. I will use between 5-10 cameras depending on how many I can get hold of and how many I need to fully cover the track. I am going to make the track myself so I can always adjust the track to my number of cameras. I should probably keep the number of cameras down for this first time.

    My PC is an almost brand new Lenovo Laptop:

    ThinkPad P17 Gen 1 with Intel Core i7-10850H vPro (2.70GHz, 12MB) 17.3 1920x1080 Non-Touch, Windows 10 Pro 64, 32.0GB, 1x1TB SSD, M.2 2280, PCIe Gen3x4, OPAL2.0, TLC, Quadro RTX 4000 8GB, WiFi6 AX201 2x2, IR&HD Cam Mic, 6 Cell Li-Pol 94Wh

  • JodiW
    JodiW Oxford, UKPosts: 1 Just Starting Out

    Thanks everyone for the tips on this feed. I just tried doing this with 7 cameras. I was playing a piece of music and only one camera so recorded multiple performances. Fortunately, with the music playing it was easy to find the transients of the drums and line it up.

    But I find the hitfilm editor pig slow when I have more than a couple of layers. I was doing a cut-through the layers approach, but you seem to have to clean up any footage underneath the clip you want to use, otherwise the renders take forever.

    I didn't bother with a multi-screen shot. Instead, I turned on a layer at a time, reviewed what footage I wanted in the next bit, then essentially cropped everything else out. I moved along measure by measure pretty much.

    It served its purpose, I cut a 4min piece in a day, and it's not even music video-style fine cutting. but it's very inflexible if I needed to come back to it to do any adjustments. I feel I'd have to go back to the original synced file save (the tip with saving into new files helped a lot!).

    I wish hitfilm could cover all my editing needs, but this particular task it sucks at. All the things I seem to want to do seem to bring out the slowest performance in the hitfilm editor. I found scaling also seems to kill the editor, even in comp mode (I can't believe a 2019 Ryzen 2nd gen desktop is a slouch). Even a flag somewhere to turn off layer blending in preview renders would be a little help. Maybe a more ideal solution might be a special lock mode for synced layers where you're only selecting which bits of the layer content is visible or not, rather than actually cutting the content (e.g. editor works as normal, but if you had cut an area then you can right-click on an empty area and do a restore block or something).