Blender EEVEE Ray Tracing Settings: An Interior Rendering Guide

Blender’s EEVEE documentation explains how ray tracing, fast indirect lighting and shadow settings affect image quality and performance. This guide looks at these options in the context of an interior visualization workflow. The online manual pages covering ray tracing and lighting do not specify a shared Blender version number. The light probes page, however, is labelled Blender 5.3 Manual. The steps below therefore describe the documented behavior of the settings; do not assume that every option is available in a single version.

1. Choose a ray tracing method and resolution

1. Check the Method option in the Render › Raytracing panel. In EEVEE, ray tracing aims to calculate indirect lighting from surfaces more accurately. When ray tracing is disabled, a faster rendering path using prefiltered light probes is activated. This alternative may be worth considering when visual accuracy is not the priority.

2. The Light Probe method finds scene intersections using light probe spheres and planes. Although the documentation describes it as the method with the lowest tracing cost, the probes must be placed manually in the scene. For a fixed interior camera, check the indirect lighting in the areas covered by the probe placement.

3. Screen-Trace searches for ray intersections based on screen depth. If a ray leaves the view, the method falls back to light probes. For scenes that depend on reflections or indirect lighting from surfaces outside the frame, do not rely on screen tracing alone.

4. Lowering Resolution can speed up ray tracing and reduce memory use. The trade-off is a potentially blurrier image. First assess the lighting and materials at a low resolution, then check the level of detail needed for the final frame.

2. Target Screen-Trace issues

The following options are available only when Screen-Trace is enabled. Thin surfaces, reflections and geometry near the edge of the frame can make their effects noticeable in interior scenes.

1. Precision determines the accuracy of screen-space intersections. Higher values can improve intersection accuracy and reduce some artifacts, but they shorten the maximum tracing distance and increase performance cost. Rather than raising the value indiscriminately, compare results when you encounter a noticeable intersection problem.

2. Thickness determines how thick surfaces visible in the depth buffer are considered for ray tracing. Higher values can reduce missed intersections, but may extend reflections and cause flickering. Lower values can make intersections more precise, but increase the chance of missing thin surfaces. Compare changes from the same camera angle.

3. When Backface is enabled, rays hitting the back side of visible geometry also count as valid hits. This can help reduce light leaks when using screen-space global illumination. Radiance Scale controls approximately how much the indirect light from front-face lighting affects back-face hits.

4. Denoising can reduce noise in raw ray-traced output and improve image stability, but it can also make the result excessively soft. Spatial Reuse reuses rays from neighboring pixels and can cause light leaks between surfaces. Temporal Accumulation accumulates previous ray tracing results to reduce glint artifacts, but may introduce color shifts. This option may be useful when temporal stability in the viewport or faster render convergence is needed.

3. Balance Fast GI and noise settings

Fast GI Approximation offers an alternative to ray tracing for high-roughness BSDFs. According to the documentation, it can produce less noise and capture reflected lighting more efficiently than calculating it with individual rays. Because it operates in screen space, the limitations of screen-space techniques also apply.

1. Threshold determines the roughness level up to which ray tracing is used. BSDFs with roughness above the threshold gradually use Fast GI Approximation. At a value of 1, all surfaces are ray-traced and Fast GI is disabled. This is a behavior described in the documentation, not a recommended value for every scene.

2. For Fast GI, Ambient Occlusion shades distant lighting from light probes using scene intersections and is described as the fastest option. Global Illumination accounts for light reflected from nearby objects. Lowering the Fast GI resolution can reduce render time and memory use; keep in mind that the result may be blurry.

3. Rays determines the number of GI rays used per pixel at the specified resolution. Increasing the value can reduce noise. Steps controls the number of screen samples taken for each GI ray. Higher values can reduce noise and improve quality; they can also lower the chance of missing surfaces that may reflect or block light.

4. Check shadow and lighting balance

EEVEE uses Virtual Shadow Mapping and Shadow Map Raytracing for shadows. Jitter can improve the accuracy of soft shadows, but because the shadow map cannot be cached, it must be updated for every render sample, making this setting costly in performance. Its effect is not visible in the viewport by default. When Overblur is greater than zero, the shadow becomes blurred; the documentation notes that this result is not physically accurate.

The Shadow buffer full warning means the system cannot allocate enough shadow memory. The documentation suggests increasing Shadow Pool Size or raising the Resolution Limit on some lights. If the problem persists, shadow generation can be disabled for some lights. The Jitter setting can also be tested with large lights and light leaks caused by Shadow Map Raytracing.

Clamping can help limit firefly and aliasing artifacts, which are especially noticeable on highly reflective surfaces and in dense volumes. However, limiting light intensity can also reduce the bright highlights you want to preserve. The direct and indirect light controls under Render › Light Paths › Intensity scale the light contribution. According to the documentation, these controls do not change ray depth, sampling, accumulation or performance characteristics.

Common mistakes

• Expecting Screen-Trace to provide a complete contribution from surfaces outside the frame: rays that leave the view fall back to light probes.

• Overlooking extended reflections and flickering when increasing Thickness.

• Failing to check for excessive softening in the final image when using denoising.

• Treating Jitter as a quality improvement with no performance impact.

• Forgetting that clamping may reduce bright highlights while helping to limit firefly and aliasing artifacts.

Impact on architectural visualization workflows

When choosing a method for interior renders, consider indirect lighting and reflection requirements as well as the camera frame. The Light Probe method requires manual placement; Screen-Trace relies on probes for rays that leave the view. Since resolution, shadow and ray settings affect quality, render time and memory use, it is useful to make comparisons from the camera angle you intend to deliver. The sources do not specify particular hardware requirements or licensing terms, so no general claims should be made about them.