unreal.GPULightmassSettings

class unreal.GPULightmassSettings(outer: Object | None = None, name: Name | str = 'None')

Bases: Object

GPULightmass Settings

C++ Source:

  • Plugin: GPULightmass

  • Module: GPULightmass

  • File: GPULightmassSettings.h

Editor Properties: (see get_editor_property/set_editor_property)

  • compress_lightmaps (bool): [Read-Write] Whether to compress lightmap textures. Disabling lightmap texture compression will reduce artifacts but increase memory and disk size by 4x. Use caution when disabling this.

  • denoiser (GPULightmassDenoiser): [Read-Write]

  • denoising_options (GPULightmassDenoisingOptions): [Read-Write] If enabled, denoise the results on the CPU after rendering. On Completion denoises the entire lightmap when it is finished. During Interactive Preview denoises each tile as it finishes, which is useful for previewing but less efficient.

  • first_bounce_ray_guiding_trial_samples (int32): [Read-Write] Number of samples used for First Bounce Ray Guiding, which are thrown away before sampling for lighting.

  • gi_samples (int32): [Read-Write] Total number of ray paths executed per texel across all bounces. Set this to the lowest value that gives artifact-free results with the denoiser.

  • irradiance_cache_corner_rejection (float): [Read-Write] Reject IC entries around corners to help reduce leaking and artifacts.

  • irradiance_cache_quality (int32): [Read-Write] Number of samples per Irradiance Cache cell.

  • irradiance_cache_spacing (int32): [Read-Write] Size of each Irradiance Cache cell. Smaller sizes will be slower but more accurate.

  • lightmap_tile_pool_size (int32): [Read-Write] GPU Lightmass manages a pool for calculations of visible tiles. The pool size should be set based on the size of the viewport and how many tiles will be visible on screen at once. Increasing this number increases GPU memory usage.

  • mode (GPULightmassMode): [Read-Write] Full Bake mode renders the full lightmap resolution for every object in the scene. Bake What You See mode renders only the virtual texture tiles for objects in view, at the mip level determined by the virtual texture system. The camera can be moved to render more tiles. Bake What You See mode only saves its results if you press the Save button.

  • show_progress_bars (bool): [Read-Write] If true, draw a green progress bar within each tile as it renders. A red bar indicates that First Bounce Ray Guiding is in progress. Bars may appear black in very bright scenes that have been exposed down.

  • stationary_light_shadow_samples (int32): [Read-Write] Number of samples for stationary shadows, which are calculated and stored separately from GI.

  • tile_passes_in_full_speed_mode (int32): [Read-Write] Baking speed multiplier when Realtime is disabled in the viewer.

  • tile_passes_in_slow_mode (int32): [Read-Write] Baking speed multiplier when Realtime is enabled in the viewer. Setting this too high can cause the editor to become unresponsive with heavy scenes.

  • use_first_bounce_ray_guiding (bool): [Read-Write] If Irradiance Caching is enabled, First Bounce Ray Guiding will search the hemisphere over each first bounce sample to find the brightest directions to weigh the rest of the samples towards. This improves results for interior scenes with specific sources of light like a window. The quality of this pass is controlled with the Trial Samples setting.

  • use_irradiance_cache_backface_detection (bool): [Read-Write] Further prevent leaks caused by irradiance cache cells being placed inside geometry, at the cost of more fireflies and slower sampling speed. Recommended to be used with higher irradiance cache quality (>=256)

  • use_irradiance_caching (bool): [Read-Write] Irradiance Caching should be enabled with interior scenes to achieve more physically correct GI intensities, albeit with some biasing. Without IC the results may be darker than expected. It should be disabled for exterior scenes.

  • visualize_irradiance_cache (bool): [Read-Write] If true, visualize the Irradiance Cache cells. This can be useful for setting the IC size and quality. The visualization may appear black in very bright scenes that have been exposed down.

  • volumetric_lightmap_detail_cell_size (int32): [Read-Write] Size of an Volumetric Lightmap voxel at the highest density (used around geometry), in world space units. This setting has a large impact on build times and memory, use with caution. Halving the DetailCellSize can increase memory by up to a factor of 8x.

  • volumetric_lightmap_quality_multiplier (int32): [Read-Write]

property compress_lightmaps: bool

[Read-Write] Whether to compress lightmap textures. Disabling lightmap texture compression will reduce artifacts but increase memory and disk size by 4x. Use caution when disabling this.

Type:

(bool)

property denoiser: GPULightmassDenoiser

[Read-Write]

Type:

(GPULightmassDenoiser)

property denoising_options: GPULightmassDenoisingOptions

[Read-Write] If enabled, denoise the results on the CPU after rendering. On Completion denoises the entire lightmap when it is finished. During Interactive Preview denoises each tile as it finishes, which is useful for previewing but less efficient.

Type:

(GPULightmassDenoisingOptions)

property first_bounce_ray_guiding_trial_samples: int

[Read-Write] Number of samples used for First Bounce Ray Guiding, which are thrown away before sampling for lighting.

Type:

(int32)

property gi_samples: int

[Read-Write] Total number of ray paths executed per texel across all bounces. Set this to the lowest value that gives artifact-free results with the denoiser.

Type:

(int32)

property irradiance_cache_corner_rejection: float

[Read-Write] Reject IC entries around corners to help reduce leaking and artifacts.

Type:

(float)

property irradiance_cache_quality: int

[Read-Write] Number of samples per Irradiance Cache cell.

Type:

(int32)

property irradiance_cache_spacing: int

[Read-Write] Size of each Irradiance Cache cell. Smaller sizes will be slower but more accurate.

Type:

(int32)

property lightmap_tile_pool_size: int

[Read-Write] GPU Lightmass manages a pool for calculations of visible tiles. The pool size should be set based on the size of the viewport and how many tiles will be visible on screen at once. Increasing this number increases GPU memory usage.

Type:

(int32)

property mode: GPULightmassMode

[Read-Write] Full Bake mode renders the full lightmap resolution for every object in the scene. Bake What You See mode renders only the virtual texture tiles for objects in view, at the mip level determined by the virtual texture system. The camera can be moved to render more tiles. Bake What You See mode only saves its results if you press the Save button.

Type:

(GPULightmassMode)

property show_progress_bars: bool

[Read-Write] If true, draw a green progress bar within each tile as it renders. A red bar indicates that First Bounce Ray Guiding is in progress. Bars may appear black in very bright scenes that have been exposed down.

Type:

(bool)

property stationary_light_shadow_samples: int

[Read-Write] Number of samples for stationary shadows, which are calculated and stored separately from GI.

Type:

(int32)

property tile_passes_in_full_speed_mode: int

[Read-Write] Baking speed multiplier when Realtime is disabled in the viewer.

Type:

(int32)

property tile_passes_in_slow_mode: int

[Read-Write] Baking speed multiplier when Realtime is enabled in the viewer. Setting this too high can cause the editor to become unresponsive with heavy scenes.

Type:

(int32)

property use_first_bounce_ray_guiding: bool

[Read-Write] If Irradiance Caching is enabled, First Bounce Ray Guiding will search the hemisphere over each first bounce sample to find the brightest directions to weigh the rest of the samples towards. This improves results for interior scenes with specific sources of light like a window. The quality of this pass is controlled with the Trial Samples setting.

Type:

(bool)

property use_irradiance_cache_backface_detection: bool

[Read-Write] Further prevent leaks caused by irradiance cache cells being placed inside geometry, at the cost of more fireflies and slower sampling speed. Recommended to be used with higher irradiance cache quality (>=256)

Type:

(bool)

property use_irradiance_caching: bool

[Read-Write] Irradiance Caching should be enabled with interior scenes to achieve more physically correct GI intensities, albeit with some biasing. Without IC the results may be darker than expected. It should be disabled for exterior scenes.

Type:

(bool)

property visualize_irradiance_cache: bool

[Read-Write] If true, visualize the Irradiance Cache cells. This can be useful for setting the IC size and quality. The visualization may appear black in very bright scenes that have been exposed down.

Type:

(bool)

property volumetric_lightmap_detail_cell_size: int

[Read-Write] Size of an Volumetric Lightmap voxel at the highest density (used around geometry), in world space units. This setting has a large impact on build times and memory, use with caution. Halving the DetailCellSize can increase memory by up to a factor of 8x.

Type:

(int32)

property volumetric_lightmap_quality_multiplier: int

[Read-Write]

Type:

(int32)