Blender Compositor Glare Node Guide: Light Bloom in Architectural Renders

What you’ll learn in this tutorial

In this guide, you’ll learn how to use the Glare Node in Blender’s Compositor to add light bloom to architectural renders. You’ll work with soft effects such as Bloom and Fog Glow, control bright areas with Threshold, and explore the Glare Node’s different outputs. You’ll also see how to prepare a source image for Sun Beams and save the final image.

Glare doesn’t recreate the lighting in a render; it generates an effect over the image based on its bright areas. So think of it as a way to adjust light accents in the final image, not as a substitute for scene lighting. In interior visuals, keeping the effect around windows or light fixtures restrained can help balance it with the rest of the image.

Requirements

This guide uses Blender and a render image to work on. The source guide covers the Glare Node in the current Blender documentation but doesn’t specify a version number. So no version requirement is given here. The documentation also doesn’t mention account or payment requirements or any specific hardware requirements.

After creating a new node tree in the Compositor, enable Compositing Pipeline in the Post Processing settings under Output Properties so the render processes the tree. If this option is disabled, the compositing setup may not affect the render.

Steps for using the Glare Node

1. Create a node tree in the Compositor

Open the Compositor and click the New button at the top to create a new compositing node tree. This node tree is added as a scene-linked data-block. According to the Blender documentation, it can be reused in different scenes or linked and appended from other blend files.

Then check the Post Processing section in the output settings and enable Compositing Pipeline. This setting is important for including the node tree in the render process. You can set up the nodes that will process the image in this tree; the Compositor processes a single image, a numbered image sequence, or a movie frame at a time.

2. Pass the image through the Glare Node

Bring the render you want to process into the node tree and connect it to the Glare Node’s Image input. Use the node’s Image output to get the image with the effect applied. This output provides the final image with glow added.

Choose an effect type in the Glare Node to define the look. Bloom and Fog Glow can be used for a soft glow around bright areas. Unlike Bloom, Fog Glow aims for a more physically based light-scattering effect; calculating it may take longer.

Other options produce different visual results. Ghosts creates overlapping streaks that resemble lens reflections. Streaks produces lines extending from bright points, while Simple Star gives a simpler star-like appearance. Sun Beams simulates light rays created when bright light scatters through an environment. The Kernel option lets you use a custom filter defined with numerical values or an image.

3. Adjust the area and intensity of the glow

Threshold controls which areas are included in the glow calculation. Lowering this value causes the effect to consider more of the image, while raising it emphasizes the brightest points. For example, if areas beyond the highlights around a window start to glow, try increasing the threshold.

Smoothness determines how soft the transition is between bright areas and the effect. Strength adjusts the overall intensity: values above 1 amplify the glow, while values below 1 blend the effect more with the source image. Saturation changes the effect’s color saturation, while Tint changes its hue.

For Bloom, Fog Glow, and Sun Beams, Size controls how far the effect spreads across the image. Clamp and Maximum can be used in renders with highly variable brightness. Clamp limits highlights that exceed the brightness level set by the Maximum input, which can help make bloom look more consistent across the image.

4. Choose the preview quality

The Quality setting determines the image resolution at which the Glare effect is calculated. High works at full resolution. Medium and Low reduce the processing resolution to lower the computational load; Low is the fastest option, but effect details may appear more limited.

So it can be useful to preview while adjusting settings at lower quality, then switch to High when evaluating the final image. In particular, making the final check at high quality helps reveal any loss of detail in renders where fine light accents or small bright objects matter.

5. Set the light source for Sun Beams

For the Sun Beams effect, first identify the bright area from which the rays should originate. The Blender guide recommends using a separate light-source image, adjusting its brightness and contrast to leave only strong highlights, reducing shadows and midtones, or using a mask.

Once you’ve generated rays from the prepared source image, you can add the effect over the main render. According to the guide, a simple Add Mix node is usually enough for this composite. The Sun Position setting determines where the rays start in the image. When you enable Active Node Gizmo in the Node Editor and select the Glare Node, a gizmo appears in the image preview so you can adjust the Sun Beams position.

6. Check the outputs and save the image

The Glare Node’s Image output provides the image with the effect applied, the Glare output provides only the generated glow, and the Highlights output provides the bright areas used to create the effect. Inspecting these outputs separately lets you assess where the glow comes from and how it spreads across the image.

You can create a single image with the Render button and save it with Save Image. The saved file format depends on the image format settings in the Render panel. For an image sequence, use the Animation button and the relevant settings. If you’ll be compositing the image later, choose PNG for alpha channel support; if you need depth information, choose EXR for Z-depth channel support.

Impact on architectural and visualization workflows

The Glare Node can be used by visualization teams and students who want to adjust light accents in architectural renders during post-processing. Its separate Glare and Highlights outputs make it possible to assess the effect separately from the source render. However, because the node is used for compositing, it doesn’t replace scene lighting or material settings.

The source documentation doesn’t specify hardware requirements or a Blender version number. So it’s important to check the interface and options in the Blender version you’re using, especially when sharing files within a team. Choose the delivery format according to the needs of the project, too: determine in advance whether you need an alpha channel for compositing or Z-depth for depth information.

Common mistakes

• Setting Threshold too low can include a much larger part of the image in the glow, not just the light source.

• Increasing Strength while ignoring Size and Threshold can make the effect too prominent in the render.

• Feeding the entire image into Sun Beams without preparing a source can cause rays to originate from unwanted areas. Consider isolating the bright areas or using a mask.

• Leaving Compositing Pipeline disabled can prevent the node tree from being used in the render output.

• Saving without considering the file format needed for the final image can leave you without the alpha or depth information you need later.

Next steps

On the same render, start by choosing a Glare type and adjusting Threshold and Strength in small increments. Compare the Image, Glare, and Highlights outputs to see which areas are generating the effect. For a Sun Beams test, isolate the light-source image or use one of the masking methods. At the final stage, increase the quality and check that the output format includes the channels required for delivery.

Sources and license

This guide is based on the Glare Node and Compositing Introduction guides in the Blender Manual. Both sources are licensed under CC BY-SA 4.0; the content has been translated and adapted into Turkish, with the explanations rewritten in original wording.