• Should be preferred for high-quality and fast photorealistic animations and walkthroughs.
  • Absolute control over what features should be rendered.
  • Fastest engine for scenes with many lights.
  • Used only in Production Mode.
  • CPU only
  • Biased engine based on Field Mapping and Final Gathering techniques.


  • Supersampling: Improves antialiasing of the rendered image at the expense of increased memory.
    None: No Supersampling, Normal: 2×2, High: 3×3 and Auto: no supersampling.
  • Motion Blur: Enables/Disables motion blur for all animated objects in a scene.
  • Displacement: Enables/Disables displacement for all materials having Displacement enabled.
All materials in the scene will be rendered as diffuse gray with respect to bump and transparency.

  • Reflectance (%): Increases/Decreases materials reflectance (from black to white)
  • Threads: Number of threads to be used while rendering.
  • Seed: Specifies the initial number for the random number generator engine. It is best to leave the default value (auto) and let the engine decide.
  • Priority: It is best to leave this to the default value (low). Low Priority does not mean low performance but is generally stable.
  • Network: NoneServer: Current machine + all network nodes, Pure Server: only network nodes
  • Server Port: Should be left at the default value, except if there is any other application utilizing the select port number.


  • Tracing Depth: Sets the global tracing depth for Global Illumination (GI) and Ray Tracing. Increase this value in cases of black areas behind transparent objects.
  • Glossy Depth: Sets the global value for the Tracing Depth of glossy materials. Each material can override this value.
  • Trace Reflections: Enables/Disables Reflections.
  • Trace Refractions: Enables/Disables Refractions.
  • Trace Transparencies: Enables/Disables Transparencies.
  • Trace Dispersion: Enables/Disables tracing of Dispersion.
  • Russian Roulette: Acceleration mechanism for tracing reflections/refractions based on a brightness threshold. Should be enabled by default.
  • Brightness: The brightness threshold for the Russian Roulette. Should be enabled by default.
Both Min AA Subdivs and Max Subdivs values are based on the Max Contrast (%) value.

  • Min AA Subdivs: Sets the minimum subdivision level for Antialiasing (AA).
    If the contrast between 2 pixels is less than the Max Contrast (%) value, then the Min AA Subdivs will be used.
  • Max AA Subdivs: Sets the maximum subdivision level for Antialiasing (AA).
    If the contrast between 2 pixels is above the Max Contrast (%) value, then the Max AA Subdivs will be used.
  • Max Contrast (%): Based on the percentage entered here, it controls whether Min or Max AA Subdivs will be used.
    Lowering this value will trigger the engine to use the Max AA Subdivs more.
  • Clamp Level: Limits brightness of over-exposed pixels to the defined value, improving antialiasing.
    The brightness of the image will be lowered significantly when this value is less than 1.
  • Enable: Turns on illumination for all the lights in the scene.
  • Adaptive Sampling: Accelerates rendering when there are many lights in a scene. Should be enabled by default.
  • Max Error (%): Maximum allowed error for Direct Lighting computations. Higher values will speed-up ray tracing in expense of noise.
  • Enable: Enables sampling of blurred reflections.
  • Evaluate GI: Disabling this will cause blurry reflections to only get sampled by Direct Lighting, which leads to missing reflections from indirect light areas.
  • Min Blurred Subdivs: The minimum antialiasing samples for blurry materials. This value can be overridden on a material level.
  • Max Blurred Subdivs: The maximum antialiasing samples for blurry materials. This value can be overridden on a material level.
  • Enable: Enables sampling of blurred reflections.
  • Affect GI: When On, Ambient Occlusion (AO) will not be added to the Global Illumination color.
    Useful when you want to add AO as a render pass in post-production.
  • Multiply: By default, AO gets added in the color render in additive mode (good for interior scenes). Enable this option when rendering exterior scenes.
  • Clamp: Enabling this option, all rays will be clamped to the shortest one, resulting in a darker AO.
  • Samples: The number of samples used for AO. Increase samples when AO appears to be grainy.
  • Distance: Occlusion distance in meters.
  • Low Color: Defines the occlusion color
  • High Color: Defines the ambient color.


  • Enable: Enables/Disables Field Mapping technique. For exterior scenes, Field Mapping should be disabled, as it could lead to slower renders.
  • Force Nearest Cell: Accelerates Field Mapping when enabled. In case of light leaks in final renders, uncheck this option.
  • Field Density: Higher values will give a denser map with more accurate results. Low values may lead to light leaks or splotches. Values between 100000 and 2000000 will give the best results.
  • Cell Size: Higher values will give more accurate results.
  • Max Error (%): Defines the error threshold for Field Map calculations. Should be left at the default value (2%).
  • Enable: Enables/Disables caustics calculation.
  • Sharpening: Enabling this option will cause caustics to be sharper with the expense of increased render time.
  • Captured Photons: Defines the amount of caustics photons that will be captured. For scenes with Distant Lights like the Sun, a higher number will be needed. Higher values will give more accurate caustics patterns.
  • Estimation Photons: Defines the number of caustic photons to be mixed together. Lower values will give a sharper caustics pattern.
  • Enable: Final gathering should always be enabled.
  • Samples: Defines the amount of samples for final gathering. This value depends on whether Field Mapping is enabled or not.
  • Diffuse Depth: Defines the amount of light bounces in the scene. This value also depends on whether Field Mapping is enabled or not.
  • Max Error (%): Defines the maximum error value of the Final Gathering solution. The default value is the recommended one.
  • Trace Reflections: When turned on, reflections of materials will be traced and calculated by the engine. Using the default state (Off), will speed-up rendering with nearly no visual loss in Global Illumination.
  • Trace Refractions: When turned on, refractions of materials will be traced and calculated by the engine. It is not recommended to disable this setting as it would lead to unresolved areas behind transparent objects (black areas).
  • Trace Glossy Reflections: When on, traces Glossy Reflections. It is unchecked by default because there is no visual loss in Global Illumination quality.
  • Trace Glossy Refractions: When turned on, refractions of materials will be traced and calculated by the engine. For the same reason as in “Trace Refractions” it is recommended to have this option enabled.
  • Enable: Enables Irradiance Cache computation.
  • Sample Density (%): The percentage defines how fine and detailed the computation will be. One of the most important parameters. It is recommended to use values between 65% to 95%. Higher values will give more accurate results in the expense of increased render time.
  • Min Distance (px): Defines the minimum distance in pixels for fine detail sampling. Higher values will cause the disappearance of fine details and may result in making objects to appear floating (contact shadows). It is recommended to use values between 0,1 to 4.
  • Max Distance (px): Defines the maximum distance in pixels for the Irradiance computation. Lower values will give more samples which mean more accuracy in the expense of increased render times. The default value is recommended for most of the scenes.
  • Prepass Level: Controls the quality for the Irradiance Cache result. You should increase this values when there are discontinuous sampling on final details. The default value of 2/1 is good starting point.
  • Density Boost (%): Adds additional samples in Sample Density. It can help reduce an artifact in the rendered image called “clouds” where we get uneven shadow/clouds on walls or ceilings.
  • Adaptive Density: Adds, adaptively, samples in the scene based on Max Contrast (%) value. It should always be enabled for interior scenes and helps to keep Final Gathering samples to a normal level.
  • Max Contrast (%): This values controls the Adaptive Density value. Based on this value more or less samples will be calculated by the irradiance cache solution. Lower values will add more samples. The default value of 2 is a good starting point.
  • Force Interpolation: Should always be enabled. Only in situations where we get discontinuous lines or missing samples and Min/Max Distance (px), Prepass Level, Sample Density (%) are not helping, disabling this option might help, with increased render times.
  • Prepass Only: When enabled, it will stop the render automatically when the Irradiance pre-computation has finished. This is very useful if you combine it with the Visualize option. In this way, it will be possible to visualize the distribution of the Global Illumination solution.
  • Visualize: Enable this option if you want to visualize where Thea is adding samples in the scene. Samples will be represented by red small dots.


  • When rendering Interior images, always turn on Field Mapping and leave Final Gather samples to the default values. In Exterior scenes, Field Mapping will not help and rendering may become slower.
  • Select a very fine Prepass Level (2/1, 4/1, etc)to avoid discontinuous samplings.
  • “Cloud” artifacts can be avoided by increasing the Density Boost percentage. You can use values larger than 100% but not higher than 1000%.