Pro Split-Screen Compositing
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Sometimes when you have two actors on screen, they don't have their best performance in the same take. Or maybe they didn't even exist in the other take. So today, I'll show you how to combine two shaky handheld shots that aren't even shot on a green screen. By using an invisible SPLIT SCREEN trick using Fusion in DaVinci Resolve.
Now, the goal of this split composite Technique isn't to highlight some fancy Picture in Picture collage effect, so if that's what you're looking for, it will be in another tutorial.
I'm showing you today the invisible art of masking and combining actors' best performances into a single hero shot to help tell the best story. In fact, not only does it let you pick the best performances for each actor or even a specific actor's body part, but you already know editing is all about timing and pacing. Well, a split composite gives you the freedom to change reaction and interaction times for every pixel on the screen. Compressing and expanding time by just a few frames can make all the difference if your audience laughs or cries.
And there probably isn't a popular show or movie that doesn't use this editing trick. So let's dive into how it works, specifically on the Fusion page of DaVinci Resolve.
Edit Page Timing
Start on the edit page by picking out your favorite ranges and stacking them up on top of each other. You can enable or disable the top layer with D on the keyboard or use the crop tool in the viewer.
Next, make sure you set your timeline resolution to your clip resolution, and then you can right-click your shots to create a new Fusion Clip.
The 4-Step Process
Following this 4-Step Technique to combine multiple handheld shaky shots, you'll be surprised how simple it can be to create new hero masters or clean up some continuity for a simple over-the-shoulder cut. The Process goes as follows: Stabilize, Mask & Merge, De-Stabilize, and a final Scale Up to hide transparent edge pixels.
Step 1: Locked off Stabilization (Match Move - Merge BG Only)
In Fusion, add a point tracker after each of your media in nodes. Each moving shot needs to be locked down just as if it was shot on a tripod, and that can be done by adding three tracking points to the points list. Ideally, you want to track one point at a time to verify the results are accurate.
Ideal tracking patterns have high contrast (bright to dark area). They're sharp, in focus, on the same plane, and don't have any obstructions or things moving in front of them in the frame. They also need to be on a fixed object in the frame. Moving people won't help you solve a camera stabilization problem.
You can suspend tracking points by clicking them twice on the tracker list and even renaming them to use in later tools in your Fusion Flow Setup. This makes it so that the good previously tracked data is not overwritten when you track new points.
You can also track based on the R, G, and B color channels to get a stronger contrast and a more accurate track. Just click the color you want in the pattern area of the inspector panel.
Finally, once you have points all attached and tracked, you change the operation, match move, merge mode to BG only, for background only under the match move setting in the inspector. BG only will stabilize the shots.
Rinse and repeat on both move shots with their own point tracker node tool.
Step 2: Mask & Merge
To mask, you add a polygon tool and click and draw around one-half of the frame that you want to reveal (or conceal). White reveals, and black conceals. You can even soften the mask with the soft edge control or turn the mask into a double poly to control just the precise softness of a single edge at a time.
Remember to disable the shape animation on the polygon if you don't intend to do any rotoscoping.
Once the polygon is drawn, you can attach it to the blue mask input of the merge node. The white area of the polygon will reveal the foreground image input. This can always be reversed with the inspect control to apply the mask inverted if needed.
Finally, you tweak the alignment of the two stable images with the merge apply mode set to "difference ."When you see a black image, there is no difference. And when that is all setup, you change the merge apply mode back to normal.
Step 3: De-Stabilize (Match Move - Merge FG Only)
The fanciest way this effect is sold is by putting the exact same camera motion back into the merged composite. You do this with just a copy and paste of whichever tracker tool you want the camera movement to add back in.
Paste a copy of the tracker after the merge, and make two simple changes.
1 - Change the match move operation merge setting away from BG only and put it to FG only for Foreground only. FG will reapply the original movement we removed to combine the shots.
2 - The tracker tool has no Foreground input currently. So drag another output from the merge tool into the Foreground of the copied tracker tool.
And that's it! You now have the exact pixel location from the original plate from which you copied the tracking data. Both shots should move in tandem.
Step 4: Scale Up and Position
A final simple transfer tool gets added to the end of the setup before sending it back to the media out. Use this to do a simple Repo, and scale the image up to hide the transparent edge pixels from this unique magic trick.
You now have that hero shot that we always wish was shot on set!
A cool thing about Fusion is that it only computes the changes once when you do stabilization and reverse the stabilization, even after moving some pixels around on the frame. It's one "concatenation" and stuff like this that makes me super excited to do Hollywood-level tricks cutting here in my house, in a converted basement bedroom.
My name is Chadwick, and this channel is called Creative Video Tips, and it's here for you! I'm here for you. Let me know what you want to learn about. I have a couple of decades of pro editing experience, and I love teaching DaVinci Resolve. So if you have stuck around till now, THANK YOU! Share this video with your friends to show them WHY THEY SHOULD EDIT WITH RESOLVE and because there is so much more to learn… I'll see you in that next video!
