General Settings

The General settings tab includes the render settings that affect the appearance of the rendered image.

UI Path: ||Render settings window|| > Corona > General settings tab

Pass limit – Number of passes after which the rendering stops.

Time limit – The time after which the rendering stops (hours, minutes, seconds).

Noise level limit – Sets the target error (noise level) at which the rendering stops.

GI Mode – This is the Global illumination solver that is used for the primary (first) light bounce.

Available GI Modes:

None (direct only) – This mode disables GI calculation.
Single bounce – Using this option only calculates the first light bounce and no furthermore (GI is also disabled when using this mode).
Full (multiple bounces) – This mode calculates the direct lighting + the GI using any of the available GI solvers.

GI Solver – This is the Global illumination solver that is used for the secondary (second, third, ...) light bounces.

Available GI Solver options:

Path tracing – Path tracing is a rendering algorithm that computes the final image by tracing independent light paths from the camera. It is useful mainly in exterior scenes, where UHD Cache would require longer precomputation times and wouldn't be able to improve rendering speed.
UHD Cache – It is a slightly biased, cached solution that speeds up rendering - it should be used (but doesn't have to) as the secondary GI solver in scenes where GI is dominant (e.g., interiors, scenes with many light bounces).
4K Cache – This is an experimental solver.

Render only masks (disable shading) – Enables rendering for mask passes only and skips rendering of beauty-dependent passes. This is useful for quickly rendering masks without the need to spend time on other passes.

Mtl. override – Enables the override material that will be applied to all scene objects. This is useful for creating "clay renders" (usually for debugging problematic scenes).

Override settings – The following options allow you to discard the overriding material for the given material's característics.

Preserve displacement – Avoids the overriding of materials using the displacement channel.
Preserve glass materials – Avoids the overriding of materials using the refraction channel.
Preserve light material – Avoids the overriding of Corona Light materials that are being used in the scene.
Preserve unsupported materials – Avoids the overriding of unsupported materials in the scene.

Include/Exclude – This list allows you to include or exclude objects from being affected by the material override option depending on the include/exclude selected method.

Available include/exclude options are:

Apply override only on these objects and materials – Applies the overriding material only to the objects in the list.
Don't apply override on these objects and materials – Prevents the overriding material from being used in the objects from the list.

Include children – Considers nested objects (children objects) for the include/exclude list. This way, there's no need to define every single object, only the grouping objects.

The render selected option allow you to include or exclude a selected object (or group of objects) from the rendering process without the need to hide all unwanted objects in the Object Manager. 

Available modes are:

Disabled – Makes no change in rendering.
Include list – Enables a list, and only objects added in that field are rendered.
Exclude list – Enables a list, and the objects added in that field are excluded from being rendered.
Viewport selection – Uses only actively selected objects to be rendered.
Object ID – Renders only objects with a specific Object ID.

The following options specify the post-render image denoising. If enabled, the beauty element is replaced with its denoised version after rendering. You can then use the Denoise Amount option to interactively control the effect's strength. The following denoising modes are available:

None – This mode disables any kind of denoising.
Only firefly removal – This mode is a fast filter that just removes very bright pixels from the image (created by any source like noise, caustics, sun reflections, etc.).
NVIDIA GPU AI (fast preview) – This option is a very fast denoiser that also denoises the image during rendering, not just at the end. Not suitable for denoising animations. Available only on NVIDIA GPUs when the optional NVIDIA AI Denoiser Corona component has been installed.
Intel CPU/GPU AI (speed-quality hybrid) – This mode is also known as Intel Open Image Denoise – Fast denoising filter and it's applied when render ends. It is a CPU-based denoiser, running on both the Intel and AMD CPUs. It does not have any additional requirements to be executed; if your CPU runs Corona, it can run this denoiser. It is slower than NVIDIA GPU AI denoiser but can achieve better quality.

Corona high quality – This mode is a more memory and CPU-intensive filter available exclusively in Corona. It takes the longest to compute but produces the best denoising quality of all integrated denoisers.
Gather data for later – This mode just gathers denoising data for later processing via the Corona Image Editor.

Show in post – Displays the denoised image in the Corona VFB.

Denoise amount – This option is a mixing coefficient between the original (noisy) and processed (non-noisy) image. It allows fine-tuning the effect strength to find the sweet spot between preserving the finest details and removing excessive noise. This parameter can be changed interactively after rendering.

Denoise radius – Controls the blurring radius of the Corona High-Quality denoiser. Increasing the value can prevent splotches when denoising extremely noisy images, and lowering it can prevent loss of details, but the default value usually works best. This parameter must be set before rendering - it cannot be changed interactively after rendering like the Denoise amount.