Beginner Screen Replacement Tutorial for Resolve
Download the practice ProRes footage used in the tutorial in the Cutting Club.
Referenced Composition
There are five ways to work with Fusion in DaVinci Resolve. There’s the standard timeline clip composition, which is my typical go-to. This clip comp involves placing the playhead over the clip you need to do some VFX with and clicking the Fusion button. I love this method because it retains the source timecode and resolution of the actual footage. Other ways include creating a blank fusion composition from the effects pallete, and there is also the ability to make a “fusion clip,” which is a mixed-down precomposed compound clip (this sucks because you lose resolution and timecode). Then there’s the VFX connect clip, which will open in the standalone version of Blackmagic Design’s Fusion app. But this brand new referenced composition method has a trick up its sleeve - the ability to swap screen inserts quickly on the edit timeline.
Using the replace edit function, you can quickly swap a still element or video clip and slip it after making the referenced comp. This allows you to fine-tune the timing of any action on screen. The timeline slip edit will help you avoid the complicated, confusing mess of the Fusion page keyframe timeline. Another significant benefit of these referenced comps is that they will work with the native resolution of the source footage (and not the timeline resolution), which will always allow for more precise masking and keys.
VFX Color Management
DaVinci Resolve is the king of color management, and it’s easy to work with the DaVinci YRGB Color Managed project-wide color science setting. For this tutorial and the effort to keep it simple, the option to keep this in automatic mode for an HDR working color space is perfect. The HDR preset allows for Rec2020 primaries, which are as wide as just about any camera for their available “box of crayons.” It will also correctly map the gamma (brightness values) back to a screen (like rec709), so you don’t have to do any fancy curves by hand.
We use color management and color transforms for VFX because we work with so many shots using formats and elements to build shots into combined, linear working color space to achieve a consistent, photo-realistic VFX composite.
How to Create a Referenced Fusion Composition
To create your first Fusion-referenced composition - right-click on the highest video clip in a stack and choose the contextual option to create a referenced composition. That’s all there is to it. Give it a name, and a clip will be placed in your media pool bin. At this point, I will ensure the timeline playhead is over the clip and that you can click to open the Fusion Page.
I discovered that if any motion tracking is involved like there is with a screen insert shot, you will want to duplicate your background footage on the top layer before creating this referenced composition, and having the duplicate on top sets your frame range, which is what gets keyframes with the tracking data. After opening Fusion, disable the topmost Media In node with the “Passthrough” P command. This is essentially making the top Media In layer invisible.
Point Tracker
Fusion inside of DaVinci Resolve Studio 19 has a new AI-based intellitrack system that tremendously simplifies the point-tracking process. In fact, intellitrack is the new default in Resolve Studio. The pattern boxes detect objects more so than contrast areas. And when you need to track modern screens, phones, or televisions, you’ll often find a ton of shiny reflections. Even with a planar tracker - YOU CAN’T TRACK REFLECTIONS! So this is when the standard old point trackers come into play.
Make use of four individual Intellitrack point trackers in each corner of the screen, change the operation mode to corner positioning with Merging FG (foreground) over BG (background), change the “apply mode” to screen, and enable motion blur in the settings tab. That’s it!
If you have an occlusion for a point you want to corner pin, use the Append Track dropdown to track a nearby object on the same plane as the camera. The object can continue the same displacement path for that tracker even though it can’t “see it.”
Finally, you can move the points out or in from the actual tracking feature with the tracker offsets. These can even be keyframes to fix any tracking that has slipped a little over time.
Brightness Contrast Node
The brightness/contrast bc node is one of Fusion's most powerful and valuable nodes. Maybe the merge is number one, but this would not be far behind. The reason I love it so much is that it’s lightweight. It won't slow your comp render time down! And when you do VFX for screen replacements, you often need to bring the gain value down to let it sit in the scene a little better. So, because we are already working in a linear light space behind the scenes in Fusion with Resolve Color Management enabled. We can simply lower the gain slider. This reduces the exposure of the screen insert, which is exactly what I would suggest doing for most on-screen graphics.
Magic Mask
The magic mask is the final node you’ll often reach for when you need a quick rotoscope for any occlusion in a composite. For example, in the YouTube tutorial, pipe the footage directly into the yellow input of the magic mask, load it into the viewer, and drag a stroke onto the part of the frame that needs to be isolated. Click the better option will create a softer, more realistic mask.
The final two steps are to connect the output of the magic mask (the grey square), into the blue effect mask triangle of the tracker node. And then lastly, in the tracker node, check the box to apply the mask inverted under the settings tab.
Final Tips
On the edit page - use the “smart” render cache under the playback menu (up at the top) for better performance and to get real-time playback.
The replace edit (F11) will match the source playhead to the timeline playhead. Replace Edit is my preferred way to update new versions of the element going into the screen. The caveat is to ensure enough footage on both sides of the playhead to “fill up” the clip. No in or out marks are needed, but you do need to patch in the track destination (the orange box).
A slip edit is a great way to fine-tune video footage inside the screen insert. To view the result of the playhead during the trim, uncheck the box under the bottom of the view menu called “show multiview edit preview.”
Color grading will happen on the actual referenced fusion composition, not the elements of the stack underneath it.
Render in Place is always a good option when you want to commit the effects to the timeline, and you can always revert to the editable referenced composition later on for tweaks.
Is this solution pixel-perfect? No. Does it get you 90% of the way there in 5-10 minutes? I think so. Please let me know in the comments if you’d like to learn more advanced compositing techniques or if you just dipped your toes in Fusion and need the basics like this one. I want to help teach you what you need to know. And because there’s so much more to learn… I’ll see you in the next video!