Rendering

When working in Batch, Batch FX, or the Timeline, you can get instant feedback when viewing and playing back clips without the need to render. To output your clips, however, you do need to render. In many areas of Flame, rendering is straightforward by using the Render button, or contextual rendering options. In most cases, rendering clips and sequences from the Workspace only renders the required effects and transitions (and not all effects and transitions located on multiple video tracks).

When you use Burn or Background Reactor to render, some situations will interrupt or outright cancel a background render job:

Modifying a segment: If you modify a segment, any background job that already exists for that segment is cancelled. This saves the GPU from processing content that is no longer current.
Deleting an FX: If you delete a Timeline FX being rendered in the background, that background task does continue. This protects the Undo stack, making sure that if you undo the deletion of the Timeline FX you do get back the Timeline FX and its cached media.
Playback: During playback, background tasks (caching, media export, Burn and Background Reactor) are paused to protect real-time playback. You can force background jobs to execute during playback by disabling Protect Playback in the General Preferences, in the Background Tasks section.

Rendering Preferences

A few options are avaialble in the General Preferences to help you set default rendering settings. See General Preferences for more information.

Note: Rendering differences may occur when using different generations of graphics hardware on different systems.

Using Hardware Anti-Aliasing

Hardware Anti-Aliasing can be enabled in some tools to smooth edges. The amount of Hardware Anti-Aliasing applied is the same for each tool of a same project. The value is set in the Rendering tab of the Project preferences.

Note: The Hardware Anti-Aliasing values differ between Rocky Linux and macOS.

Use the Use HWAA button from the Node Prefs menu of the Action, Burn-In Metadata, GMask, GMask Tracer, Image, Subtitle, Text, and Type tools to determine if the project's hardware anti-aliasing sampling level is applied to a Node or Timeline FX.

When enabled, the tool uses the hardware anti-aliasing sampling level set in the Rendering tab of the Project Preferences.
When disabled, no hardware anti-aliasing is applied.

Note: The status of Use HWAA is saved in the setups.

The default status of the Use HWAA differs from one node to the other.

ActionA: The default status can be set at the user level in the Action / GMask Tracer / Image tab of the User Preferences.
Burn-In MetadataA: Enabled by default.
GMaskA: Enabled by default.
GMask TracerA: Enabled by default.
ImageA: Disabled by default.
SubtitleA: Enabled by default.
TextA: Enabled by default.
TypeA: Enabled by default.

Loading Setups from Previous Versions

When loading a Batch setup saved in a version older than 2026, the application may adjust the project's Hardware Anti-Aliasing option and the status of the Output Precision to preserve the setup's integrity.

When the setup's hardware anti-aliasing value is higher than the project's value, the following rules are applied:
- If the setup's hardware anti-aliasing value is higher than the maximum hardware anti-aliasing level available, one of the following happens:
  - If the project is already at the maximum hardware anti-aliasing value, a dialog message warns that the value cannot be changed.
  - If the value can be increased, a dialog message gives the options to raise the hardware anti-aliasing to the maximum allowed value or not.
- If the setup's hardware anti-aliasing value is available but different, a dialog message gives the options to keep the current project's value or use the setup's value.
When the setup's hardware anti-aliasing value is lower than the project's value, the latter is preserved.
If the setup's output precision is 32-bit and the project's output precision is set to 16-bit, a dialog message gives the options to keep the current project's precision or use the setup's precision.

Note: The Hardware Anti-Aliasing and Output Precision parameters from Batch FX segments and Clip History are ignored.

The status of the Use HWAA parameter is set to the tool's default value since it was not available in previous versions. The only exception is Action, where Use HWAA is enabled if the setup requires hardware anti-aliasing and disabled otherwise.

Background Reactor

Background Reactor is a background rendering service. Using Background Reactor allows you to continue working while effects are being rendered on the same workstation the application is running on. It can be used in dual-GPU (Rocky Linux only) or single-GPU (Rocky Linux and macOS) configurations.

Each environment (Conform, Timeline, Effects, and BFX) has its own rendering setting (foreground or background). The default Rendering mode (Foreground, Burn, or Background Reactor) is defined in the General Preferences, in the Default Rendering Options section.

Do not worry about Background Reactor monopolizing your system resources. Background Reactor only starts when you set the Render menu to Background Reactor (Auto or not). If you exit Flame while Background Reactor is still processing jobs, Background Reactor will only shut down once all relevant tasks are completed.

Background Reactor requires specific hardware on Rocky Linux, listed on the system requirements page.

For information on how configure Background Reactor, see Background Reactor.

Automatic Background Rendering

When in the Conform, Timeline, and Effects environments, Flame can automatically render Transitions and Timeline FX in the background.

To enable automatic background rendering, select Background Reactor (Auto) from the Render drop-down button.

With Background Reactor (Auto) selected, the text of the Render button changes from white to blue.


	Click Reactor to send the whole sequence to background rendering.
	Click Reactor Sel to send only the selected segments to background rendering.

With Background Reactor (Auto) enabled, a segment automatically starts rendering in the background when:

You scrub the positioner away.
You unselect the segment.

Note: In the Timeline, if you are working on a selection of segments, rendering tasks are never sent automatically to Background Reactor. This is to avoid bombarding Background Reactor with too many work-in-progress tasks. This is also why if you modify a vertical FX in Timeline, nothing is sent automatically when you change the track focus on a shot boundary. In both cases you need to click the Render button.

Burn

Burn allows you to render images in the background using low-cost Linux workstations, freeing your workstation for more creative tasks. With Burn, facilities can leverage a larger pool of rendering power so that complex visual effects requiring intensive processing can be created more quickly. See Set up a render node with Burn for more information on how to install and configure Burn to work with Flame.

Static Frame Pipeline Optimization

Rendering media can be time-consuming, and depends on a number of factors, including the type of media and the effects applied to it. Static frame pipeline optimization can significantly decrease rendering times for sequences or Batch or Batch FX schematics that use static source generators (such as the Colour Source node, for example), static media (stills), and static effects. A static effect is one that is not animated over time, such as static Type or a static GMask. When rendering static media, the result of a static source generator or a static effect, Flame renders and caches a single static frame, and uses that frame for the duration of the static element, rather than rendering each individual frame. This enables noticeably shorter rendering times.