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# DaVinci Resolve 3D Keyer: Green Screen Setup and Fixes
- URL: https://davinciresolveclub.com/davinci-resolve-3d-keyer/
- Published: 2026-10-21T05:40:00.000Z
- Updated: 2026-10-21T12:07:11.000Z
- Description: Build a green-screen composite on the Edit timeline. Check sampling, alpha and track overlap before adjusting the matte or removing green spill.
- Author: Jason Miller
- Tags: Fusion, Tutorials, #learn, #fusion-cluster

To remove a green screen with DaVinci Resolve’s **3D Keyer**, put the foreground clip above your replacement background on the Edit timeline. Apply 3D Keyer to the foreground, open Inspector → Effects, set the Timeline Viewer to **Open FX Overlay**, and drag a sample across the screen color. For the finished view, choose **Final Composite** and enable **Use Alpha**.

For a straightforward, evenly lit screen, I’d start here, because the composite stays on the timeline. If the picker does nothing, check the overlay before changing the key. If the matte changes but the background stays hidden, check alpha and the tracks before adding more samples.

[Download](https://streamly.surf/c/2ebmf2MxAg6s?ref=davinciresolveclub.com)

## Which 3D Keyer do you need?

This guide covers the **Resolve FX 3D Keyer on the desktop Edit page**, using the Resolve 21.1 reference controls. It’s built in: Blackmagic lists [3D keyers among the free version’s tools](https://www.blackmagicdesign.com/products/davinciresolve/studio?ref=davinciresolveclub.com), so this workflow doesn’t require a separate plugin or a Studio purchase.

The name refers to sampling a three-dimensional range of color values. It doesn’t mean you need a 3D model, camera or Fusion 3D scene. The Color page’s 3D qualifier is related, but a Color-node tutorial has different routing steps. For a more detailed node-based green-screen workflow, use the separate [Fusion Delta Keyer guide](https://davinciresolveclub.com/davinci-resolve-delta-keyer/).

## Stack the clips and apply the effect to the foreground

1. Open the Edit page with both clips in the Media Pool. Put the replacement background on **V1** and the green- or blue-screen foreground on **V2**.
2. Align them so they overlap at the playhead. A background that ends before the foreground cannot appear through the rest of the shot.
3. Open **Effects**, then find **Open FX → Resolve FX Key → 3D Keyer**. Drag the effect onto the foreground clip on V2.
4. Select that foreground clip and open **Inspector → Effects**. Expand 3D Keyer if its controls are collapsed.

![Edit timeline with a selected green-screen performer on V2 above an overlapping theatre background on V1, and 3D Keyer applied to the foreground.](https://storage.ghost.io/c/a9/29/a929429b-cfab-4467-b902-a0cd9c90feac/content/images/2026/10/davinci-resolve-3d-keyer-tracks.webp)

Apply the keyer to the upper foreground clip. The lower clip supplies what will appear through its transparent areas.

If a search returns nothing, check its scope. The Effects Library search dropdown can search **All Folders** or only the current folder, as described in the [Effects Library search controls](https://documents.blackmagicdesign.com/UserManuals/DaVinci%5FResolve%5F21%5FReference%5FManual.pdf?ref=davinciresolveclub.com#page=1144). Searching inside an unrelated category can hide the effect you need. That doesn’t mean the keyer was removed from Resolve.

## Enable the viewer overlay, then sample the screen

Use the **Timeline Viewer** showing the selected foreground clip. At its lower-left corner, open the viewer overlay dropdown and choose **Open FX Overlay**. It’s the same control you use for Transform and other on-screen tools. Some interface text and manual sections call it Open FX or Open FX Overlays. This mode lets the effect’s sampling tools receive your drag in the viewer.

Choose the plain **Picker** eyedropper in 3D Keyer, then click and drag a stroke across a representative patch of green or blue. Keep it off the person, clothing and soft subject edges. A stroke samples a range of screen pixels; one isolated click may not describe the backing well enough. Blackmagic’s [3D Keyer sampling controls](https://documents.blackmagicdesign.com/UserManuals/DaVinci%5FResolve%5F21%5FReference%5FManual.pdf?ref=davinciresolveclub.com#page=3572) explain the difference between broader strokes and narrow samples.

![Timeline Viewer with a blue sampling stroke on empty green backing beside a performer and Open FX Overlay selected below the viewer.](https://storage.ghost.io/c/a9/29/a929429b-cfab-4467-b902-a0cd9c90feac/content/images/2026/10/davinci-resolve-3d-keyer-picker.webp)

Turn on Open FX Overlay before sampling. Keep the first stroke on the backing, away from the subject.

Turn on **Show Paths** if you want the sampling strokes to remain visible. Then refine the selection deliberately:

- **Picker + / Add:** sample screen shades that the first stroke missed, such as a darker patch of backing. Add only what you need.
- **Picker − / Subtract:** exclude a color accidentally included in the selection. Use this when a sample starts removing part of the foreground.
- **Delete Stroke:** remove the selected entry from the Stroke list if one particular sample made the key worse.

**Reset** is a larger change: it deletes all strokes and returns the keyer to its default state. Don’t reach for it when removing one bad stroke would preserve the rest of your work.

## Inspect the matte before fixing spill

Scroll to **Output** and choose **Alpha Highlight B/W** to inspect the alpha. In the finished matte, the subject should be white where it needs to stay opaque, while the removed backing should be black. Soft gray transitions can belong at hair and motion-blurred edges; forcing every edge to pure white or black can destroy that detail.

If the person disappears while the backing remains, check **Invert**. It reverses the key selection. Set it by the matte you need, and don’t toggle it just because a tutorial happens to do so.

For the replacement view itself, return Output to **Final Composite** and check **Use Alpha**. These [output and alpha controls](https://documents.blackmagicdesign.com/UserManuals/DaVinci%5FResolve%5F21%5FReference%5FManual.pdf?ref=davinciresolveclub.com#page=3576) determine how the keyed clip composites over another video track. A black-and-white diagnostic view is useful while you adjust the key, but it isn’t the finished picture.

![3D Keyer output controls showing Alpha Highlight B/W for matte inspection and Final Composite with Use Alpha checked for the theatre replacement view.](https://storage.ghost.io/c/a9/29/a929429b-cfab-4467-b902-a0cd9c90feac/content/images/2026/10/davinci-resolve-3d-keyer-alpha.webp)

Inspect the alpha, then return to Final Composite with Use Alpha enabled to judge the replacement background.

### Choose the adjustment that matches the defect

I’d keep **Flat** as the starting behavior for green- or blue-screen work, because it’s the mode the detailed 3D Keyer chapter recommends. Don’t change every control simply because it’s available. Start with better samples, then choose the smallest adjustment that addresses the remaining defect.

- **Screen shades remain selected unevenly:** Chroma Tolerance expands or contracts the selected color range. Chroma Softness changes the transition around that range. Watch the subject as you adjust either one.
- **White specks remain in the black background matte:** a restrained increase in Clean Black can remove them. It can also erode translucent edges.
- **Black pinholes appear inside the white subject matte:** Clean White can fill them, but it also grows translucent edges. Keep checking hair, fabric and gaps between fingers.
- **Compression blocks interfere with sampling:** Pre Filter acts before the color samples are processed. Judge whether it helps the matte without sacrificing useful detail.
- **The edge looks harsh:** a small Blur Radius adjustment may soften it. A larger blur can create a halo around the subject, so inspect the composite as well as the matte.

These are the documented functions of [Matte Finesse](https://documents.blackmagicdesign.com/UserManuals/DaVinci%5FResolve%5F21%5FReference%5FManual.pdf?ref=davinciresolveclub.com#page=3575). They aren’t a universal settings recipe: the right amount depends on the screen, compression and foreground detail. Check several frames before deciding that one adjustment solved the shot.

### Use Despill for green or blue contamination

Once the matte is usable, adjust **Despill** to reduce reflected green or blue on the subject. It corrects color contamination and doesn’t replace the alpha setup. Turning a green backing gray isn’t the same as making it transparent.

The detailed Resolve 21.1 chapter describes a Despill slider; older lessons may show a checkbox. Follow the control available in your version, and compare skin, hair and clothing over the actual replacement background. More suppression isn’t automatically a better color match.

## 3D Keyer not working: check the stage that failed

### The eyedropper does nothing

Reselect the foreground clip, open its 3D Keyer controls in Inspector → Effects, and set the Timeline Viewer overlay to Open FX. Select Picker and drag across the backing. If the matte now changes, the sampling route works, so refine the selection from there. Increasing Clean Black can’t fix a viewer that was never sending the effect a sample.

### The backing becomes gray, or you only see a matte

Check Output first. Alpha Highlight and Alpha Highlight B/W are inspection modes; use Final Composite for the replacement view. If only the backing’s color changed, inspect the alpha separately. Despill may have reduced its green without producing the transparent areas you intended.

### The matte looks right, but the background does not appear

Enable Use Alpha and confirm that the background clip sits below the foreground and overlaps the current playhead. Also confirm that you applied the effect to the upper clip. This is the Edit-page timeline route, so you don’t need to build a Color-page Alpha Output connection to follow these steps.

### The subject has holes, missing edges or a green rim

I’d separate transparency from color first, because a solid matte with a green rim calls for a different correction from a matte that has cut through the person. Check the alpha for an overbroad sample or reversed selection before increasing cleanup. Remove the offending stroke or subtract the accidentally selected subject color. Only then decide whether Clean White, a small edge adjustment or Despill addresses what remains.

### Lights or the edge of the screen remain in the frame

Use **Garbage Matte** to exclude areas outside the useful performance region. Its Matte Shape options include Rectangle and Ellipse; None disables the crop. Open FX Overlay exposes the shape’s on-screen controls. Leave room for the subject’s full movement, then play through the shot: a crop that clears a light stand can also cut off an outstretched hand later.

### You are trying to remove black rather than green

That’s a brightness-selection task. Blackmagic recommends the HSL or Luma keyer when you need control over a range of luma values. Keep in mind that a brightness key can also remove equally dark parts of the foreground, and the background’s color alone doesn’t make it separable.

## When I’d move the shot to Delta Keyer

Stay with 3D Keyer when a few sensible samples and restrained cleanup produce a useful matte through the whole shot. I’d move to [Delta Keyer’s more detailed matte and edge controls](https://davinciresolveclub.com/davinci-resolve-delta-keyer/) when uneven backing, fine hair or contaminated edges keep forcing compromises. That gives you a more structured refinement workflow instead of an ever-growing collection of samples.

The [Fusion guide hub](https://davinciresolveclub.com/davinci-resolve-fusion/) covers those node-based next steps. If you already have the composite you need but want to deliver the keyed foreground as its own file, follow the separate [transparent-video export guide](https://davinciresolveclub.com/davinci-resolve-export-transparent-background/). Making transparency inside the timeline and preserving it in an exported file are separate decisions.