How this family works
Material is assigned to geometry. Objects, camera and lights enter Merge3D through parallel branches; Renderer3D outputs the image for 2D compositing.
What classic Fusion 3D is
A classic Fusion 3D branch contains objects in a coordinate space. Geometry, 3D text, image planes, cameras, lights and materials are assembled into a scene rather than layered directly as 2D pixels.
That scene can be transformed and viewed from different cameras without re-rasterizing every object at each step. The conversion to a normal image happens only when Renderer3D evaluates the scene from a camera.
Merge3D is not the normal Merge
Merge3D combines scene elements that coexist in 3D space. It does not place one flat image over another the way the regular Merge does. Several objects, cameras and lights can feed a Merge3D and remain distinct 3D entities.
A normal Merge expects images. Therefore a Merge3D output normally goes to Renderer3D first. The Renderer3D output is then a regular image that can be connected to a 2D Merge.
The main pieces of a 3D scene
Geometry defines form: Text3D, Shape3D, ImagePlane3D and imported meshes are common examples. Transform3D positions scene elements. Camera3D determines the viewpoint. Lights and materials control how surfaces respond visually.
Renderer3D resolves those scene relationships into pixels. Its settings affect quality, lighting, shadows, transparency and other render behavior, so it is both a technical boundary and a creative part of the scene.
When 3D is worth using
Use 3D when perspective, parallax, camera movement, volumetric positioning or lighting relationships matter. 3D titles, screen walls, product cards, layered image planes and camera-driven motion are common production cases.
If the visual can be built as two flat layers with a simple scale or position animation, classic 3D may only add complexity. Choose it when the spatial relationship is part of the design.
Returning to the 2D composite
A clean workflow often ends the 3D branch at Renderer3D. From there the rendered image is merged over live footage and matched with ordinary Blur, Glow, color, matte and grain tools.
Keeping that boundary clear prevents the common mistake of trying to feed a live 3D scene into nodes that only understand pixels.
Practical example: a 3D title inside a 2D shot
A typical title setup starts with Text3D or another 3D object, combines scene elements through Merge3D, adds Camera3D and one or more lights, and then uses Renderer3D to turn the scene into an image.
Only after Renderer3D should the title be treated like a normal layer. A regular Merge can place it over MediaIn, and ordinary 2D tools such as Glow, Blur, Color Corrector or masks can finish the integration.
This example shows the essential boundary: Merge3D assembles objects that still live in a scene, while Merge assembles rendered images. Keeping those jobs separate prevents one of the most common architectural mistakes in Fusion.
Connect material to geometry; connect cameras and lights to the scene
A texture feeds a compatible material input; the material feeds the geometry’s Material input or ReplaceMaterial3D. The shaded object, Camera3D and SpotLight enter Merge3D through independent branches, and the resulting scene feeds Renderer3D. Materials, lights and cameras are not sequential image effects after Merge3D.
For footage on a plane inside the scene, use MediaIn → ImagePlane3D → Merge3D. For final compositing, keep footage in 2D: MediaIn → Merge Background and Renderer3D → Merge Foreground. Choose according to whether the plane must participate in camera/object relationships or simply form the final background.
Black renders, missing shadows and the wrong camera
First check the camera selected in Renderer3D: the Viewer’s free perspective is not necessarily the final render view. Then check object position, near/far clipping, scale and normal orientation. Adjust material only after those checks; increasing specular cannot reveal an object outside the camera frame.
Lighting and shadows depend on the selected renderer, its settings, the light and the object’s properties. Check Lighting/Shadows where those options are available, and confirm material support in Software/OpenGL. Judge antialiasing and motion blur in the final Renderer3D output rather than solely in the interactive 3D Viewer.
Which node to choose?
| Node / group | Task | Check before using |
|---|---|---|
| Text3D / Shape3D | Geometry | Position, normals and assigned material |
| ImagePlane3D | Image on a scene plane | UV, size and transparency |
| Camera3D / lights | Viewpoint and lighting | Separate connections to the scene |
| Merge3D | Combine scene elements | Scene data is not yet an image |
| Renderer3D | Scene → image | Camera, Lighting/Shadows and alpha |
Three working setups
Extruded title
Text3D + Camera3D + SpotLight → Merge3D → Renderer3DMaterial is assigned to Text3D; the result can feed ordinary Merge FG.
Footage in 3D space
MediaIn → ImagePlane3D → Merge3D → Renderer3DCamera3D joins the scene separately and defines the plane’s perspective.
Finish only the 3D layer
Renderer3D → Color Corrector → Glow → Merge (FG)The BG plate stays separate; inspect alpha and color before final assembly.
A dependable workflow
- 01
Create geometry with Text3D, Shape3D, ImagePlane3D or an importer.
- 02
Assign material to geometry; connect textures to the appropriate material inputs.
- 03
Prepare Camera3D and lights as separate branches; position the object with Transform3D.
- 04
Combine geometry, camera and lights with Merge3D.
- 05
Select the camera, renderer, dimensions, lighting and shadows in Renderer3D.
- 06
Finish the image in 2D and feed Merge Foreground; footage feeds Background.
- 07
Check alpha, edges, color, motion blur and the complete shot.
What usually goes wrong
Confusing Merge3D with the normal image Merge.
Trying to connect a live 3D scene directly to ordinary 2D image effects.
Forgetting that a camera determines the final rendered view.
Adding lights without considering whether the selected material actually responds to them.
Building a 3D scene for a task that would be simpler and faster as 2D motion graphics.
Ignoring render quality and alpha settings at the Renderer3D boundary.
Continue with the official guide
Examples explain the connection logic. For the exact controls and availability in your installed version and edition, use the corresponding Blackmagic Design manual.
- Fusion 19 Reference Manual
Data types, tool inputs, masks, particles and 3D.
- The Visual Effects Guide to DaVinci Resolve 20
Practical compositions, Match Move, Planar Transform and animation.