Track and Blur Key Mixer Tutorial
DaVinci Resolve has some of THE BEST tracking and masking tools of any video editing software, but sometimes - shapes get complex enough to warrant splitting them into separate nodes - like blurring the face of this woman on the bench that is behind a dude walking in front of her. Today, I’d like to teach you color page tracker essentials AND how you can combine multiple masks with the Key Mix node on the color page to combine a power window and a Magic Mask for any occlusions you might need to deal with…
For our cutting club members that want to follow along, the footage is up at creativevideotips.com/cuttingclub to download and play along. Thanks to you for supporting and growing this channel.
Step 1 - Circle Mask Face
Start with a circular power window with the center anchor point over the nose.
Remove edge feathering softness for a cleaner tracking result, you can add that back later while in the “clip” mode of the tracker
Move to the color page tracker palette, uncheck the unecessary options (maybe 3d), and start tracking on the LARGEST AND SHARPEST frame.
If the shape needs to run off-screen, look for objects nearby with the same motion and reposition the power window to overwrite bad tracking data.
Delete bad tracking data by lasso dragging a box around the keyframes in the tracker you want to remove and click the three dot options menu to remove selected tracking data.
Enter full on manual mode by clicking the “frame” tab in the tracker pallete. Start by setting a keyframe on the last good tracked from from the clip tab, and then move to a moment later in time to reposition the power window manually back on the subject. The anchor point should remain the same, ideally the nose of a person.
Step 2 - Magic Mask Occlusions
Find a frame that is largest and sharpest for the foreground occlusion object.
Go to the object mask, magic mask pallete on the color page and use the eye dropper tool to swipe over contrast regions of the frame to create a reference frame selection.
Click the mask overlay button in the tracker pallete to highlight the selection as a red overlay.
Set the mode to better, for a more refined edge on the matte creation.
Finally - just hit track forward and backward to track the magic mask.
If necessary, create negative strokes with an option drag with the eyedropper if the selection does not fully cover the occlusion subject.
Step 3 - Key Mixer Node
Right click in an empty area of the node graph and choose to add a node - key mixer.
The key mixer node combines multiple alpha channel masks to combine them in useful ways.
For this example connect the blue output of both the power window circle mask node, and the magic mask node into the key mixer. By default they are added together.
But to exclude the occlusion from the power window, choose invert and mask from the key pallete and the result is perfect to send into a blur node downstream.
Step 4 - Blur
Add one more corrector node to perform the blur on the original graded footage.
The blur and sharpen pallete is one good option for a smooth looking blur, but there is also a resolve fx mosaic blur that can be applied for the pixelated style.
The final blur node should get the blue masking alpha transparency information from the output of the Key Mixer node.
