Scene
Iray Rendering Modes
Iray Photoreal: This is the photo- and physically realistic mode in Iray, which uses complex global illumination effects. This mode offers a maximum quality but takes longer to calculate the refinement of the image.
Iray Interactive: This raytracing mode uses progressive rendering that allows you to take advantage of the effects of a raytracer without giving up interaction and editing capabilities. This mode does not provide physically realistic rendering.
Blend: Render convergence begins in Interactive mode and then switches to Photoreal mode after a certain level of refinement is achieved. In high-interactivity situations, this mode allows for more fluid interaction while still aiming for increased realism once the interaction has ended. Because both rendering modes are used, this mode consumes more memory resources during the conversion of the scene.
Refinement stop criteria
Multiple criteria are available to define the end of the refinement phase. The rendering will stop as soon as the first limit is reached.
Max samples per pixel: the higher the limit, the better the quality and the longer the rendering time
Max quality: expressed as the rate of convergence per pixel, from 0 to 1, where 1 represents an infinite convergence
Max time: maximum duration of the calculation in hours, minutes and seconds before stopping the refinement
Max path length: in number of bounces
Render Settings
The optimization settings favor certain phenomenons or characteristics that are physically present in the scene in order to make the final convergence for these elements visible earlier during the rendering.
Caustic sampler: uses a sampling strategy to favor the calculation of caustics
Architecture sampler: allows earlier appearance of the light in interior spaces
Enable Environment Material support allows you to view an environment material in the viewport of Matter.
Warning
For closed decors (such as a hemisphere) on which the material Environment is applied, matte material or Iray ground is not compatible with the above parameter. This parameter can be deactivated (unchecked) to instead show up the Iray environment that supports matte material and Iray ground.
A rendering difference may appear between Iray and OpenGL, that's why you can use the Use alternative texture parameter to prevent blurring when the HDR or EXR file applied to the background texture of the environment is in low resolution. Patchwork 3D will instead load an alternative non-HDR texture which results in an alteration of information related to the intensity of the light. You will find additional information related to the Environment material in the following chapter: Using an Alternate Background Texture as an Environment Material.
Tip
The best option to have a similar rendering between Iray and OpenGL is instead to use a high resolution wide dynamic range HDR as the environment texture and uncheck the Use the alternative texture parameter.
In the event that the Environment material is not used, Set the background mode to environment parameter is required to display the Iray environment. This is to apply the background mode Environment to the sensor in use. You will find additional information on how a sensor works in the following chapter: Sensors (Editor).
Ground
The ground, when enabled, simulates an infinite plane, covered in the equivalent of a matte material. In background mode, it includes the reflections of and influence of the product's environment.
Altitude: height of the ground along the Y axis
Shadow intensity
Scale: adjusts the scale of the environment
Glossiness: glossiness of the ground
Reflectivity: reflection color for the ground
Filtering Settings
Filters reduce certain artifacts associated with the non-convergence of pixels. Filters can impose an additional calculation load, which can taken up, in part, by the CPU.
Fireflies: filters bright points
Degrain filtering: produces a smoothing of the rendering. Five modes are available:
Pixel clipping
Smart median
Smart average
Limited blur
Limited auto blur
In ascending order, the Pixel clipping produces a soft smoothing while the Limited auto blur produces a strong smoothing.
Note
Modes 4 and 5 of degrain filtering are not physically realistic.
Denoise filtering
The Patchwork 3D rendering engine supports the new algorithms for intelligent noise reduction by NVIDIA Iray. During progressive refinement it is now possible to obtain a noise-free rendering from a threshold defined in advance.
From the user-defined threshold of the Minimum iterations, intelligent noise reduction algorithms perform a process to make the image look sharper.
The higher the threshold, the more intelligent noise reduction occurs late in rendering.
The lower the threshold, the more intelligent noise reduction occurs early in rendering.