Flares OFX 1.4 Technical Documentation

Windows:

General Installation Steps

Our plugin installs just like any other OpenFX plugin.

1. Download the plugin archive
2. Extract the files if needed.
3. Copy the plugin folder into your system’s OpenFX directory. Common locations include:
   • Windows: C:\Program Files\Common Files\OFX\Plugins\
   • Linux: /usr/OFX/Plugins/ (currently not supported)
4. Restart your host application to load the new plugin.

Important Notes

• Paths vary depending on the host application.
  For example, Nuke also checks .../OFX/Nuke directories and supports the OFX_PLUGIN_PATH environment variable for custom locations.
• Other hosts (e.g., Resolve, Fusion, Vegas, Natron, etc.) may use only the shared OFX/Plugins folder or provide their own installation guidelines.

We strongly recommend checking your host application’s documentation to confirm where it expects OpenFX plug-ins to be installed.

Linux:

Flares OFX is available for Rocky Linux 8 and 9 and includes RPM packages for streamlined installation.
The Linux version of this plugin is compatible with Nuke and other OFX-supported hosts.

Choose the appropriate RPM package for your system:

• Rocky Linux 8:
  flares-ofx-studio-1.4.10-1.el8.x86_64.rpm
• Rocky Linux 9:
  flares-ofx-studio-1.4.10-1.el9.x86_64.rpm

Install

Using dnf (recommended, automatically resolves dependencies):

sudo dnf install ./flares-ofx-studio-1.4.10-1.el9.x86_64.rpm

Or with plain rpm:

sudo rpm -i flares-ofx-studio-1.4.10-1.el9.x86_64.rpm

(Replace el9 with el8 if installing on Rocky Linux 8.)

Verify Installation

The plugin will be installed to the directory defined by the RPM package — typically a system-wide location such as:

/usr/OFX/Plugins

Set Environment Variables

Path to custom lens systems and user data: FLARESOFX_DATA_DIR (defaults to home)

Studio version also supports setting the license key through special environment variable: FLARES_LICENSE_KEY

OFX Path

Copy or symlink the plugin folder into your OFX plugins directory. The plugin should then show up automatically in the nodes.

1. License Types

• Personal License
  A single-machine license for individual users.
  The key is activated locally and stored on that machine.
  In order to activate or deactivate the key one needs internet connection.
• Studio License (Offline Floating)
  Designed for studio environments.
  A single license key can authorize multiple workstations by referencing a shared directory.
  This allows centralized license management without requiring an internet connection.

2. License Activation

Licenses can be activated directly inside the plugin:

1. Open the Lens System Browser.
2. Click on License Manager.
3. Paste the provided license key.
4. Click Activate.

The plugin will automatically generate and store a license.json file in the working directory (either the user’s home folder or a custom path defined via environment variables).

3. Environment Variables (Offline Studio Version Only)

For the Offline Studio Version, licensing and data paths can be configured through environment variables.
This allows studios to manage licenses and shared assets centrally while keeping artist workstations clean and consistent.

# Defines the directory containing both assets and the license file
export FLARESOFX_DATA_DIR=...

Alternatively, for more control in larger studio environments, the license key can be separately set:

# Path to shared lens systems, presets, and user data
export FLARESOFX_DATA_DIR=...

# License Key
export FLARES_LICENSE_KEY="0f3b92cc82bfb245d543df3c5773bb12aa42b33483b0cb2c650d25d19..."

This configuration is specific to the Offline Studio Version and is particularly useful for studios using deployment tools (such as rez) to maintain read-only packages for the license while allowing artists to modify custom assets and presets as needed.

Lens systems are stored as JSON files.
The plugin uses two directories:

• A read-only directory where the default lens system presets are stored:
  FlaresOFX.ofx.bundle/Contents/Win64/assets/lens_systems
• A custom directory for user-created lens systems:
  $FLARESOFX_DATA_DIR/assets/lens_systems/custom

This separation ensures that factory presets remain untouched, while users can freely create and modify their own lens systems in the custom directory.

If desired, users can also add their own presets by moving custom-created lens systems into the main presets directory. When doing so, make sure to also copy the corresponding thumbnail files so that the presets appear correctly in the browser.

The plugin can operate in two modes: Linked and Baked.

• Linked Mode
  In this mode, the plugin references the lens system files directly from disk.
  Any updates to those files will automatically reflect in the project. This mode is ideal during development or when lens systems are shared across multiple shots or artists.
• Baked Mode
  Sometimes it’s important to lock a project so the lens systems cannot be modified.
  When Baked Mode is selected, the lens system is embedded directly into the node, preventing any further edits or external changes.

Switching back from Baked to Linked mode will free the baked data and restore the link to the external lens system file, effectively overwriting the baked version.

Low Quality Mesh Like Artifact – Fix : Increase Render Quality

Here you can see the clear difference between various render quality settings. However, keep in mind that render quality scales number of rays sent through the system quadratically, so increasing it too much can quickly cause the plugin to run out of VRAM. When this happens, some ghosts may fail to render properly. The next image demonstrates how to resolve this issue.
Note: Different lens systems converge at different rates. For many setups, a relatively low render quality (around 10–30) is already sufficient.

Ghost Disappearing – Fix: Enable Render Stability

Render Stability can be enabled directly in the editor or overridden through the OpenFX host’s plugin interface. When enabled, it allows the plugin to render much denser and more stable ghosts, but this comes at the cost of reduced performance.

Dispersion Color Separation – Fix : Increase Wavelength Count

Naturally, with strong glass dispersion, colors begin to separate. To handle this, you can enable the Expanded Spectrum option, which increases the number of wavelengths used during rendering. In most cases, the default setting of 5 wavelengths is sufficient, so enabling this option is usually unnecessary. However, using more wavelengths can alter the color of the ghosts, as the render becomes more physically accurate with a broader wavelength range.

If you want smoother color transitions—or simply a general blur effect—you can enable Blur in the Lens System Editor and adjust its strength. Each ghost will be blurred individually, with the amount of blur depending on its dispersion. For production use, the HQ Blur option is designed for larger blur effects, as it uses a significantly larger kernel size to achieve higher-quality results.

Drive Input:

We can start with a simple raw HDR render that serves as the driving input for the flares. Since the flares are directly influenced by the brightness and color of the input pixels, you can apply color correction beforehand to fine-tune their overall appearance.

Applying gamma correction can help balance flare intensities — either by reducing overly bright flares or boosting dim ones.

Adding a slight blur to the input can also help stabilize highlights and produce a more natural, consistent flare response.

You can also apply desaturation to reduce color variation in the flares — or increase saturation to make the colors more vivid and diverse.

Pixel Driven Flares Parameters:

Understanding what happens under the hood will make using this tool much easier—and far more powerful.

When you adjust the threshold, the plugin isolates the brightest areas of the image. For each of these bright regions, it spawns a light source, ordered by brightness (up to the maximum number of lights specified). The strength of each light is determined by the weighted brightness of its corresponding area.

Because HDR inputs can contain extremely high pixel values (sometimes exceeding 10,000.0), the resulting flare brightness might not match what you expect. To compensate, you can adjust the Light Brightness Multiplier parameter.

Example:
If an area contains pixels with RGB values around 1000.0, the flare generated from that area will have a light strength calculated as:
Light Strength = 1000.0 × Light Brightness Multiplier × Internal Constant

Enabling Pixel Driven Flares:

Note: Make sure the Pixel Threshold value is set high enough. A low threshold will cause the plugin to process too many bright areas, which can significantly slow down rendering performance.

Pro Tip: Downscale the input when you want to greatly speed up performance. The plugin can handle different resolution input than format.

When the input is ready, enable the Enable Pixel Driven Flares option. This will generate the number of lights specified by the Max Lights To Render parameter.

Preview Flare Generation:

To more easily see where the flares will be generated, enable the Preview Flares Generation option.

Green and red squares meaning:

Because rendering ghosts is computationally expensive—and in many cases only the starburst is visible—you can choose to render only the starburst effect for lights below a certain brightness level. This behavior is controlled by the Threshold To Render Only Starburst setting.

Green squares – Renders ghosts and starburst!

Red squares – Renders starburst only (and effects)!

Suggested Workflow:

1. Adjust pixel brightness threshold properly so it mainly contains the highlights you want to spawn the flares. Use Preview Flare Generation for easier adjusting. With very high resolution inputs one can also downscale the input before driving the plugin with it.
2. Disable the Preview mode to see the actual strength of the generated flares. The brightness may often appear either too strong or too dim. To correct this, adjust the Light Brightness Multiplier parameter until the desired intensity is achieved.
3. Once you’ve achieved the desired brightness, you can adjust the Threshold To Render Only Starburst setting to render only the starburst effect. This can significantly reduce computational time.
4. After that, you can fine-tune the visual details by adjusting parameters such as Blur Strength and Area Weight.