Cycles is a physically-based path tracing render engine in Blender, designed to deliver photorealistic results by simulating the behavior of light. Introduced in Blender 2.61, Cycles leverages ray tracing to accurately model reflections, refractions, and global illumination. Use this tag for any posts related to Cycles rendering.
Cycles is a physically-based path-tracing render engine with GPGPU rendering support, fully integrated and bundled with Blender.
To set Cycles as the active render engine, select Cycles from the Render Engine dropdown in the Render Properties tab.
In Cycles, materials are created using Node Trees, which are connected by Noodles. This system allows for the creation of complex materials by combining various inputs and ultimately outputting them to a Shader—a mathematical equation that describes how light interacts with the material's surface.
Rendering in Cycles is accomplished by firing and tracing virtual rays of light from the camera through each pixel. As each ray travels through the scene, the shaders determine how it interacts with surfaces, which wavelengths (and thus colors) of light are reflected. The colors of all the rays are then averaged to compute the color and brightness for each pixel.
The number of rays fired through each pixel is known as the number of Samples. A low sample count can result in noisy renders due to the inherent randomness in how rays bounce. As the sample count increases, the randomness diminishes, and the average color converges to a more accurate result. The number of samples needed for a noise-free render varies based on the complexity of the scene, ranging from as low as 25 samples for simple scenes to a few thousand for more complex ones.
Cycles is actively under development, with ongoing improvements and new features being planned and implemented. Feature tracking and updates can be found through Blender's GitHub repository, developer blogs, and community discussions.
You can read more about Cycles on the official Cycles website, as well as in the Blender Manual's Cycles section, which includes detailed information and documentation.
#Cycles related questions:
Troubleshooting common issues with enabling GPU rendering:
Enabling GPU rendering for Cycles?Differences from blender-internal:
How is Cycles different from Blender Internal?
What are the differences between lamps in Cycles and Blender Internal?Reducing noise:
How to avoid noisy renders in Cycles?
How to reduce fireflies in Cycles?
How To Reduce Noise In Cycles Render
Spherical emitter does not illuminate very well?
What is multiple importance sample option
