Voxel Probe

Voxel Probe is a light source which provides static voxel lighting and shading on an object inside Voxel Probe by using a prebaked 3D lighting map. Voxel Probe stores information on indirect lighting (light bounces) only, no direct lighting data at all. Unlike Environment Probe, Voxel Probe provides physically accurate light spreading inside interiors and outdoor static scenes but supports diffuse reflections only.

Also, Voxel Probe is great solution for shading dynamic objects within static areas.

Notice

Surfaces with enabled Lightmaps are not illuminated by Voxel Probe.

Overview#

Voxel Probe provides box volume composed of voxels and contains parameters used for light baking inside it.

Voxel Probe projects a 3D lighting texture on objects inside it thus providing indirect lighting simulation.

Notice

For a transparent object (with Alpha Blending enabled) to be affected by Voxel Probe, you should toggle on the Multiple Environment Probes state of its material and enable the Multiple Environment Probes feature (via Rendering -> Transparent -> Multiple Environment Probes).

The texture should have an appropriate resolution which is calculated the following way:

Resolution = Width × Height × (Depth × 6)

Each pixel of a texture defines the illuminance of a certain voxel face.

An example of a 3D lighting texture

The inner space of Voxel Probe is visualized using spheres. These spheres are used to show the illumination in each voxel from all directions. The visualizer is disabled by default. To enable it, use the Helpers menu in Editor Viewport:

Voxel Probe Visualizer settings:

Grid Size — number of spheres in every row/column, the value from 7 to 40.
Sphere Scale — size of the visualizing sphere.

Voxel Probe is a required object for the Voxel-Based GI feature, which enables you to generate a lighting texture for Voxel Probe and simulate global illumination with indirect lighting for both, interiors and outdoor scenes.

Notice

By default, Voxel Probe is used for lighting only; as for reflectons, it is recommended to simulate them using Environment Probe. This approach ensures the best result, however you can still enable reflections for Voxel Probe.

Adding Voxel Probe#

To add Voxel Probe to the scene via UnigineEditor, do the following:

On the Menu bar, click Create -> Light -> Voxel Probe.
Place Voxel Probe somewhere in the world.
Bake Lighting or set the Texture parameter by choosing a prebaked lighting texture from assets.

Notice

Use the Cast GI option to define if a surface should be baked to Voxel Probe.

Voxel Probe Settings#

Parameters of Voxel Probe are available in the Node tab of the Parameters window. It contains both the common and the specific parameters. A set of parameters specific for Voxel Probe is described below.

WarningDo not use the Scale transform parameter to change Voxel Probe size as it causes visual artifacts.

Voxel Probe parameters

Common Parameters#

Box Size	Specifies the size of the box volume.
Voxel Size	Sets the size of a voxel. Notice If the Box Size is not divisible to the Voxel Size without remainder, Voxel Probe uses the lowest volume of voxels covering the box.

NoticeThese two parameters define the resolution of Voxel Probe. Note that the memory usage is cubically dependent on the resolution, double growth of the voxel size causes eight-times growth of the size of the lighting texture.

Render Parameters#

Color	Sets the light color in the RGBA format. The color defines both the plausibility of virtual representation and its aesthetic component.
Intensity	Sets the light color multiplier, which provides fine control over color intensity of the emitted light: The minimum value of 1 corresponds to the least saturated light color. The maximum value of 100 equals the most bright and intense color.
Shadow Mask	The Shadow mask controls rendering of a shadow cast by an object lit by a light source.
Viewport Mask	Sets the Viewport mask for the light.
Visibility Distance	Distance from the camera, in units, up to which Voxel Probe will be rendered.
Fade Distance	Distance from the camera, in units, starting from which Voxel Probe starts to fade out gradually.
Render On Water	Renders Voxel Probe on the water surface.
Render On Transparent	Renders Voxel Probe on transparent surfaces.
Blend Mode	Toggles the blending mode for Voxel Probe. This option offers more flexibility in lighting control. The following modes are available: Alpha Blend mode is used to blend several Voxel Probe nodes with the current node overlapping other Voxel Probe nodes. The node with a smaller voxel size has a higher priority. Additive mode can be used to blend lighting of several Voxel Probe nodes together and control them separately (e.g. make a separate Voxel Probe for an indoor emissive light source and blend it with another Voxel Probe with lighting baked from the sky, having the ability to enable and disable them separately). Multiplicative can be used to blend Voxel Probe imitating ambient occlusion with the indirect lighting available underneath the probe. In order to bake ambient occlusion to Voxel Probe, you can enable the Multiply By Sky Color option, bake the probe with one bounce, and disable that option. As a result, Voxel Probe will contain white color from the sky that may be used as ambient occlusion. Notice Voxel Probe with additive blending enabled cannot be used as an inset to add lighting details (e.g. creating a small high-detail Voxel Probe inside a large low-detail one). Such nodes do not replace each other, as they are blended instead.
Multiply By Sky Color	Enables the influence of sky color on Voxel Probe. When enabled, this option makes the Voxel Probe color black at night, or orange at sunset. Notice To bake lighting from the sky separately with this option enabled, it is recommended to enable baking visibility for the sky only, while disabling it for other light sources. Changing this option requires the lighting to be re-baked.

Ambient Parameters#

Bias	Sets the bias of ambient lighting by adjusting the voxels offset for fine tuning.
Cubic Filtering	Enables the cubic filtering of ambient lighting. Notice When disabled, the linear filtering is used.

Reflections Parameters#

Enabled	Enables reflections for Voxel Probe. By default, Voxel Probe is used for lighting only; as for reflectons, it is recommended to simulate them using Environment Probe. This approach ensures the best result, however you can still enable reflections for Voxel Probe via this option.
Visibility Roughness Min	Sets the lower bound of the roughness range within which the reflections of Voxel Probe are visible.
Visibility Roughness Max	Sets the higher bound of the roughness range within which the reflections of Voxel Probe are visible. Notice The roughness range helps to choose between diffuse reflection of the Voxel Probe and other ones (reflection from an environment probe, the environment cubemap) for all materials having the Roughness parameter.
Bias	Sets the bias of reflection by adjusting the voxels offset for fine tuning.
Cubic Filtering	Enables the cubic filtering of reflection. Notice When disabled, the linear filtering is used.

Baking Settings#

NoticeThe following parameters describe the way the light shall be baked inside Voxel Probe, so you need to re-bake lighting, when you make changes to these parameters.

Baking Viewport Mask	Sets the baking Viewport mask which specifies the surfaces to be baked basing on their material's Viewport mask.
Far Clipping	Sets the distance to the far clipping plane used for every voxel during light baking.
Bake Quality	Defines the baking quality preset for Voxel Probe. Draft option provides the highest iterativity with the lowest sampling quality and number of rays simulated. Low option provides low sampling quality and number of light rays simulated. Medium option corresponds to stable quality level which is good for most cases. High option corresponds to high sampling quality and number of light rays simulated intended for release production. Ultra baking quality might be useful to get rid of small inconsistencies on the release production.
Bake Internal Volume	Defines the mode of internal volume baking of Voxel Probe. Full option corresponds to baking all voxels of Voxel Probe in the full resolution. Half option corresponds to baking all voxels of Voxel Probe as follows: voxels that cover geometry are baked in the full resolution and empty voxels are baked in the half resolution. Having baked internal volume makes it possible to realistically shade dynamic objects that move inside Voxel Probe as the lighting texture is projected onto all the geometry.
Notice You can use the following 7 visibility options together with additive blending to provide more flexibility in light baking. Thus, you can make Voxel Probe nodes independent of each other and combine them to produce some sort of dynamic GI effect.
Visibility Sky	Enables baking of lighting from the sky to Voxel Probe.
Visibility Light World	Enables baking of Light World to Voxel Probe.
Visibility Light Omni	Enables baking of Light Omni to Voxel Probe.
Visibility Light Proj	Enables baking of Light Projected to Voxel Probe.
Visibility Voxel Probe	Enables baking of other Voxel Probe light sources to Voxel Probe.
Visibility Environment Probe	Enables baking of Environment Probe light sources to Voxel Probe.
Visibility Emission	Enables baking of emission light sources to Voxel Probe.
Visibility Lightmap	Enables baking of lightmapped surfaces to Voxel Probe.
Texture	Sets the 3D lighting texture. Notice Every bake lighting procedure makes changes to the asset which is set for this parameter. You can leave the field empty to avoid losing content. In this case a new generated lighting texture will be set for this parameter after the bake lighting procedure. Generated textures are stored in the data/bake_lighting folder.

Last update: 2023-12-19

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Voxel Probe

In This Article:

See Also#

Overview#

Adding Voxel Probe#

Voxel Probe Settings#

Common Parameters#

Render Parameters#

Ambient Parameters#

Reflections Parameters#

Baking Settings#