Blender Eevee Light Probes: Adjusting Reflections and Indirect Light Indoors

What you’ll learn in this guide

Blender Eevee light probes capture specific types of light in a scene for use on surfaces. This guide focuses on two use cases: volume probes, which store diffuse light from different points within a volume, and plane probes, which capture reflections for flat surfaces. We’ll cover how to plan probe placement in interior scenes, choose baking settings, and assess issues such as light leaks or memory limitations.

The two probe types do different jobs. A volume probe captures light from all directions at sampling points distributed throughout a volume, and records diffuse light only. A plane probe, by contrast, captures light from a single direction for visible points, along the reflection direction. So for reflections on shiny, flat surfaces, consider a plane probe; for indirect lighting within a space, consider a volume probe.

Requirements

These steps are based on Blender’s Eevee light probe features. The source documentation does not specify a particular Blender version or account requirements, so no version number or account conditions are assumed here. Volume probe data is static and must be baked manually. Plane probes work only when the ray-tracing method is set to Screen-Trace.

During volume probe baking, the scene is converted to a different representation to speed up light transport. This representation can use a large amount of GPU memory. For this reason, especially in large scenes, consider scene size and available GPU memory alongside the baking settings. Also account for the fact that reflections and volumetric effects are not supported by plane probes before making design decisions.

Setting up and baking a volume probe

1. Fit the volume to the space. For interior lighting, set up probe grids that follow the room’s shape. Don’t allocate more sampling points than necessary to empty areas or areas where lighting changes little. If a particular corner or area is problematic, consider adding a smaller grid there instead of increasing the resolution of the entire volume. Large scenes may need multiple volumes at different levels of detail.

2. Set grid resolution according to your needs. The Resolution X, Y, and Z values in the probe’s Object Data > Probe section determine how many cells the local volume is divided into. Since light is captured for each cell, bear in mind that a denser grid can affect baking time and resource use. The documentation recommends avoiding high resolution in empty areas and using a small grid for problem areas.

3. Balance bake quality and cost. Bake Samples sets the number of ray directions evaluated in the calculation; increasing this value extends bake time. Surfel Resolution defines the number of surfels generated per local distance. Higher values can improve quality, but can also significantly increase memory use. The documentation suggests twice the maximum Resolution value as a good setting; treat this as a starting point, not a rule for every scene.

4. Choose which lighting to capture. The Capture section contains options for including world lighting, indirect light bounces, and emissive surfaces in the bake. Baking world lighting can produce more accurate illumination, but correct blending with surrounding irradiance volumes may be lost. Consider the indirect lighting and emissive surface options based on the types of light sources in your scene.

5. Bake the data and inspect the result. Volume probe lighting data does not update automatically; it must be baked manually. Once baking is complete, the data is stored in the object’s data-block. Check the capture points and the volume’s influence in the viewport to see whether the sampling distribution covers the space.

Setting up reflections with a plane probe

1. Choose a flat, smooth surface. A plane probe is suitable for smooth, flat surfaces. Each visible plane probe increases render time because the scene must be rendered again for that probe. Use them only on surfaces where reflections are needed.

2. Set the method to Screen-Trace. Plane probes do not work with any other ray-tracing method. When Screen-Trace is enabled, a probe can speed up the tracing process and fill in missing data from screen-space ray tracing.

3. Check the probe’s position relative to the surface. If Backface Culling is disabled, placing a plane probe flush with the surface can cause the underside of the surface to be captured. Alternatively, move the probe plane just far enough above the surface that it won’t appear in the capture, or disable probe visibility in the object visibility panel.

4. Review the influence distance and clipping offset. The plane probe’s Distance value and the object’s scale determine which surfaces fall within the probe’s influence. Only surfaces whose normals align with the reflection plane receive the captured reflection. Increasing Clipping Offset can help resolve contact issues in reflections. The Parallax setting affects the perceived depth of reflections on supported materials.

Common mistakes and next steps

One common issue with volume probes is that invalid capture points can end up inside closed geometry. The documentation’s Validity Threshold excludes points with low validity scores from light interpolation; Dilation Threshold and Radius control how data from low-validity points is filled in from valid neighbors. Before changing these settings, check the placement of probe points relative to the scene geometry and the bake coverage.

If you see light leaks, carefully assess sampling offsets such as Normal Bias and View Bias. Normal Bias shifts sampling along the surface normal, while View Bias shifts it along the view direction. Raising these values too much can create new problems: Normal Bias can make diffuse surfaces appear specular, while View Bias can produce camera-dependent results. The documentation considers View Bias preferable when the camera is stationary. Increasing Facing Bias can soften interpolation, but may also increase light leaks.

If baking exceeds available GPU memory, first consider splitting the scene into smaller sections or setting up volumes at different levels of detail. Other suggestions include lowering Surfel Resolution and disabling light probe visibility on objects that contribute little to the bake. For plane probes, remember that reflections and volumetric effects are not supported; if these limitations don’t fit the scene’s requirements, the solution may not lie in probe settings alone.

In architecture, interior design, and archviz workflows, these methods are particularly useful for teams looking to control how indirect light spreads through a space and how flat surfaces reflect their surroundings. Volume probe placement should be planned around the room’s geometry, while plane probes should be used with render-time costs and support limitations in mind. For large projects, GPU memory and baking time are as important to production as quality settings. Starting with a test in a small section of an interior makes it easier to compare the effects of different settings on the scene.

Sources and license

This guide has been adapted into Turkish using the “Light Probe Volume” and “Light Probe Plane” sections of Blender’s official manual. Both sources are licensed under CC BY-SA 4.0.