Tools > Options > Cycles

The Cycles options manage settings for the built-in Raytraced display mode.

Integrator settings

The integrator is the rendering algorithm used to compute the lighting. Cycles currently supports a path tracing integrator with direct light sampling. It works well for most lighting setups, but it is not as suitable for caustics and some other complex lighting situations.

Rays are traced from the camera into the scene, bouncing around until they find a light source such as a lamp, an object emitting light, or the world background. To find lamps and surfaces emitting light, both indirect light sampling, that is, letting the ray follow the surface bidirectional scattering distribution function (BSDF), and direct light sampling, that is, picking a light source and tracing a ray towards it, are used.


Change the seed value to vary the noise pattern.

Ray Bounces

Maximum bounces

Maximum number of light bounces. For best quality, this should be set to a high value. However, in practice, it may be good to set it to lower values for faster rendering. Setting the maximum to 0 bounces results in direct lighting only.


Maximum number of diffuse bounces. The ray is generated by a diffuse reflection or transmission (translucency).


Maximum number of glossy bounces. The ray is generated by a glossy specular reflection or transmission.


Maximum number of transmission (light that is transmitted throughout a volume) bounces.


Maximum number of volume scattering bounces.

Session settings


Amount of samples taken per pixel. More samples means better convergence, thus better quality.

Throttle (in ms)

time in milliseconds to wait between each sample pass (one pass over the entire image, sampling each pixel once). This can be used to lessen the stress on the GPU, especially useful when rendering on GPU where the GPU is also the display driver, meaning a monitor is attached to that card, and the operating system is using that to show everything on it.

Device settings

Current render device

The device selection grid is for selecting the device to render new render sessions with. A render session is the rendering progress in a Raytraced (Cycles) viewport.

The default device selection picks the first available CUDA device is installed; otherwise, CPU is selected. This means this default device differs according to the computer's hardware configuration.


This tab shows all of the devices in the central processing unit (CPU) of your computer.

When CPU is selected, all processor cores are used to render the viewport. CPU utilization can be up to 100%.


This tab shows all of the render devices in the Compute Unified Device Architecture (CUDA) category. These are the NVidia graphics and compute cards. CUDA is a parallel computing platform and application programming interface (API) model created by NVidia.


This tab shows all of the render devices in the OpenCL category. These include all devices that support the OpenCL technology, including CPUs and most graphics cards.

Open Computing Language (OpenCL) is a framework for writing programs that execute across heterogeneous platforms consisting of central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), field-programmable gate arrays (FPGAs) and other processors or hardware accelerators.

Restore Defaults

Restores the default system values. All custom appearance settings will be lost.

Save options for use on other computers


Save Options settings to a file.


Restore Options settings from a file.

See also

Render your model scene

MikkTSpace License

Cycles Render Engine




Rhinoceros 6 © 2010-2020 Robert McNeel & Associates. 13-Oct-2020