> ## Content Index > Fetch the complete content index at: https://davinciresolveclub.com/llms.txt > Use this file to discover other available public pages before exploring further. # How to Animate a Line in DaVinci Resolve Fusion - URL: https://davinciresolveclub.com/animate-line-stroke-davinci-resolve-fusion/ - Published: 2026-10-12T20:25:17.000Z - Updated: 2026-10-17T05:45:36.000Z - Description: Draw a line on a transparent layer, reveal it with Write On End, and control its timing, position and visible length. Plus the fixes for one-frame strokes, the wrong modifier and an opaque canvas. - Author: Jason Miller - Tags: Fusion, Tutorials, #fusion-cluster To animate a line in DaVinci Resolve Fusion, add a **Paint** node, choose **Polyline Stroke**, draw an open path, then keyframe that stroke’s **Write On End** from **0** to **1**. Leave Start at 0 to keep the part you’ve already drawn. For a line over footage, paint onto a transparent Background and Merge it over the clip. I’d start with that separate-layer setup for a callout, a route or a curved accent. You can change the line’s timing and position without moving the shot underneath it. The steps below use the controls documented in Resolve 21.1; the frame values are an example you can adapt to your clip. [Download](https://streamly.surf/c/2ebmf2MxAg6s?ref=davinciresolveclub.com) ## Build a transparent layer for the line Open your clip on the Fusion page. A basic clip starts with MediaIn1 connected to MediaOut1\. Add Background, Paint and Merge using the Select Tool dialog: press Shift-Space, search for the node and add it. Check the wires after each addition, because adding a selected tool can insert it into the current connection. 1. Select **Background1** and set its color **Alpha to 0**. Match its image dimensions to the footage you’re drawing over. This is a transparent canvas; the Paint brush supplies the line’s color. 2. Connect Background1’s output to Paint1’s **orange image input**. Paint needs an image to establish its canvas. The blue input is an effect mask. 3. Connect MediaIn1 to Merge1’s **orange background input**, and Paint1 to Merge1’s **green foreground input**. 4. Connect Merge1 to MediaOut1\. Load Merge1 into a viewer so you can see the line against the shot. Blackmagic’s [Paint setup instructions](https://documents.blackmagicdesign.com/UserManuals/DaVinci%5FResolve%5F21.1%5FReference%5FManual.pdf?ref=davinciresolveclub.com#page=1748) describe both this composite and the simpler alternative, MediaIn1 → Paint1 → MediaOut1\. Painting directly on the clip uses fewer nodes. A transparent branch is the better choice when you want to reposition, fade or reuse the graphic separately. ![Transparent Background feeds Paint; the painted line enters Merge’s green foreground input and footage enters its background input.](https://storage.ghost.io/c/a9/29/a929429b-cfab-4467-b902-a0cd9c90feac/content/images/2026/10/fusion-line-paint-merge.webp) Set the canvas Alpha to 0, then put Paint on the foreground branch. MediaIn stays on the background branch. If the connections still feel unfamiliar, the [Fusion node quick map](https://davinciresolveclub.com/davinci-resolve-fusion-tutorial-for-beginners/#fusion-nodes-quick-map) explains what the inputs do. Keep this composition small until the line appears correctly. ## Draw an editable Polyline Stroke Select Paint1\. In the Paint toolbar above the viewer, choose **Polyline Stroke**. Hover over the icons to find the name; choosing the default Multistroke is an easy way to draw something that disappears on the next frame. Use a **Circular Brush** for a hard-edged line and **Color** as the Apply Mode. Pick a contrasting color, keep brush opacity and color alpha at 1, and adjust the brush Size until the line is readable at the shot’s actual viewing size. 1. Click where the line should begin, then click to add the next point. Two points give you a straight line; add a few more for a bend or a curve. 2. Keep the path open for a callout or route. Don’t click the first point again unless you want a closed shape. 3. Use the polyline toolbar’s **Modify** mode to adjust points without adding more. Select the points you want curved and choose **Smooth**; use the handles to shape the bend. Keep deliberate corners Linear. 4. Switch to the Paint toolbar’s selection tool when you’ve finished drawing. Select the stroke and open the Inspector’s **Modifiers** tab. Choose the modifier for the line you just drew, such as **PolylineStroke1**, and expand Stroke Controls. Changes here apply to that stroke. Paint can also show a placeholder for the next stroke, so the last item in the list isn’t necessarily your visible line. The [documented Paint stroke types](https://documents.blackmagicdesign.com/UserManuals/DaVinci%5FResolve%5F21.1%5FReference%5FManual.pdf?ref=davinciresolveclub.com#page=2639) matter here. Stroke and Polyline Stroke are editable and normally span the composition. Multistroke is built for fast retouching, defaults to one frame and can’t be edited like a vector stroke after you draw it. Use Stroke for a freehand gesture and Polyline Stroke when you want control over the path’s points. ## Animate Write On End from 0 to 1 In the existing stroke’s **Stroke Controls**, leave **Stroke Animation at All Frames** and find the **Write On** range. Its Start and End values define the visible part of the path. Start 0 and End 1 show the whole line; Start 0 and End 0 show none of its length. 1. Move to the frame where the reveal should start. Set **Start to 0** and **End to 0**. 2. Enable animation for **End** using its keyframe diamond, or right-click the End control and choose Animate. This sets the first keyframe at the current frame. 3. Move later in the composition and set **End to 1**. Once animation is enabled, changing that value at another frame creates the next keyframe. 4. Scrub from the first keyframe to the second. The line should extend along the path, then remain visible. Confirm that you are viewing the Merge/MediaOut result and changing the modifier for the visible stroke. ![PolylineStroke1 in Paint’s Modifiers tab, with Start at 0 and Write On End keyed from 0 at frame 0 to 1 at frame 24.](https://storage.ghost.io/c/a9/29/a929429b-cfab-4467-b902-a0cd9c90feac/content/images/2026/10/fusion-line-write-on-keyframes.webp) Animate End to reveal the path. Start stays at 0 so the completed part of the line remains visible. For example, if your composition starts at frame 0, End 0 at frame 0 and End 1 at frame 24 make a one-second reveal on a 24 fps timeline. At 30 fps, use frame 30 for the same elapsed time. If your visible Fusion range starts at a different frame, count from that starting frame instead of typing 0 automatically. Move the second keyframe closer for a faster reveal or farther away for a slower one. **Duration is not the speed control for these manually keyed End values.** The keyframe spacing controls the reveal. The stroke’s lifetime decides whether the stroke exists while that reveal runs. If you’re unsure which editor owns an animation, the [keyframes and curve editor guide](https://davinciresolveclub.com/davinci-resolve-keyframes-curve-editor/#choose-the-control-that-matches-the-job) separates the Edit page controls from Fusion’s Keyframes and Spline panels. For this line, stay with the Paint stroke on the Fusion page. ### Why I use manual keyframes instead of the Write On preset The Stroke Animation menu also has a **Write On** option. According to Blackmagic’s [Write-On animation instructions](https://documents.blackmagicdesign.com/UserManuals/DaVinci%5FResolve%5F21.1%5FReference%5FManual.pdf?ref=davinciresolveclub.com#page=1758), that option creates timing keys from the frame where you created the stroke to the frame where you select the preset. Picking it at the drawing frame can leave you without the interval you intended. Manual Start/End keyframes give you an explicit beginning and finish. You don’t need to switch to the preset to animate End. If you already applied an automatic mode, inspect the keys it added before adding your own timing. ## Make the reveal smoother or turn it into a traveling segment First get the reveal working with two keys. Then open **Spline**, show the stroke’s animated End channel and select its keyframes. Right-click a selected key and choose **Smooth** to expose the Bézier handles. Shape the curve to ease into the drawing and settle at the end. Blackmagic documents these [Spline handle controls](https://documents.blackmagicdesign.com/UserManuals/DaVinci%5FResolve%5F21.1%5FReference%5FManual.pdf?ref=davinciresolveclub.com#page=1551) separately from the path’s own curve handles. These are two different kinds of smoothing. Smoothing the path changes where the line bends, and smoothing the End animation changes how quickly it’s revealed. For a technical route diagram, I’d keep linear timing unless a slower entrance helps the viewer read the graphic. For a callout, a short ease can make the movement less abrupt. To draw the line off after it appears, leave End at 1 and animate **Start from 0 to 1** later. The start of the visible line advances along the path until nothing remains. For a short segment that travels along the path, animate both values while keeping **Start below End**. For example, a visible range of Start 0.2 and End 0.4 can later move to Start 0.6 and End 0.8\. The gap between the two values sets how much of the path is visible, and the paired keyframes move that section. Don’t let Start catch End unless you want the segment to disappear. The menu’s **Trail** mode can automate a related effect, but it adds its own timing. For a segment that must hit a particular frame, I prefer the explicit Start and End keys. ## Move the line without moving the footage Write On changes how much of the existing path is visible. It doesn’t move the path across the image. For the whole graphic, add a **Transform** between Paint1 and Merge1 and animate its Center. This moves only the painted branch. A Transform after Merge1 would move the footage and line together. The stroke’s own Center, Angle and Size controls can also reposition an individual stroke. If only one endpoint needs to move, use the Polyline Stroke’s shape animation instead. At the first pose, right-click **Right-click here for shape animation** at the bottom of its controls and choose **Animate**. Move to the next pose and adjust that endpoint in the viewer. Keep the other points where they belong. This changes the line’s shape, while Center moves the line as a unit. You can also publish an individual point from the polyline toolbar when you need a separate point control or a tracker connection. That distinction resolved the endpoint problem in this [discussion about animating a callout line](https://www.reddit.com/r/davinciresolve/comments/1naa1gn/animate%5Fpaint%5Fstroke%5Fpoints/?ref=davinciresolveclub.com). A line that has to follow a moving subject needs motion or tracking data as well as a reveal; the [tracking and roto guide](https://davinciresolveclub.com/rotoscoping-davinci-resolve-fusion/#track-broad-motion-before-detailed-roto) covers that separate job. ## Fix a line that disappears or won’t animate ### The line lasts for one frame Check the stroke type. If you drew with Multistroke, redraw the line as Stroke or Polyline Stroke for editable animation. For an existing vector stroke, check its lifetime in the Keyframes panel and its Stroke Animation mode. Limited Duration can end the stroke before the reveal finishes; All Frames avoids that restriction for this setup. ### Changing End does nothing Select the line in the viewer and open its existing modifier. Don’t edit an unused next-stroke placeholder. Blackmagic explicitly describes that [extra stroke entry in the Modifiers tab](https://documents.blackmagicdesign.com/UserManuals/DaVinci%5FResolve%5F21.1%5FReference%5FManual.pdf?ref=davinciresolveclub.com#page=1757). Then verify that End has keys at two different frames and that their values differ. ### The full line appears immediately Return to the first frame of the reveal and check End. It should read 0 there, not 1\. Check for an earlier key, a second unanimated copy of the stroke, or keys placed outside the visible clip range. If the automatic preset added keys you didn’t intend, correct that timing before judging the result. ### The shot turns black, or the line is invisible A black rectangle over the shot usually means Background1 is opaque. Set the canvas Alpha to 0 while keeping the brush’s color alpha and opacity at 1\. For an invisible line, follow the output: Background into Paint’s image input, Paint into Merge’s green foreground, footage into its background, Merge into MediaOut. Also check brush Size, Write On Start/End and whether an effect mask is hiding the paint. ### The line looks dotted or rough Check brush Spacing, Size and Softness on the selected stroke, then inspect the result at the intended output size. Spacing controls the brush dabs along the path. A large number of unnecessary control points can also make a curve harder to shape cleanly. Adjust the path geometry separately from the animation timing. ## Choose a different tool when the task changes For a simple geometric outline with no brush texture, a **Polygon mask on a colored Background** is another useful route: turn off Solid and set Border Width. It defines a matte that reveals the Background’s color, rather than painting colored pixels onto a canvas. Blackmagic documents the [Polygon outline controls](https://documents.blackmagicdesign.com/UserManuals/DaVinci%5FResolve%5F21.1%5FReference%5FManual.pdf?ref=davinciresolveclub.com#page=2483); don’t look for Paint’s stroke modifiers on that node. For text appearing character by character, use the [Text+ typewriter workflow](https://davinciresolveclub.com/davinci-resolve-text-plus-typewriter-effect/). Its Write On control acts on text, whereas Paint’s Write On acts along a drawn path. Once your line is visible, the useful adjustments are usually timing, thickness and placement. Keep the original clip on its own Merge branch, and you can refine those without disturbing the shot. The [Fusion learning hub](https://davinciresolveclub.com/davinci-resolve-fusion/) has the next guides for masks, tracking and reusable graphics.