How to avoid noisy renders in Cycles?

I know that this question is a bit old or maybe overdone, but I’m running the latest edition of Blender and when I use the Cycles engine I get really fuzzy results and I can’t find a simple, non-compromising solution to the quality. I don’t know exactly what I’m doing wrong here, but I’m sure others share my frustration.

Leaving everything in default settings, I started a new project and switched to the Cycles render. I duplicated the cube and set colors for two Diffuse BSDF shaders, then went ahead and made walls and a floor all sharing the same diffuse shader. I made two windows to emit blue light. The screenshot has gaps between the walls because of the setup:
Blender Cycles render
I’m aware that it’s considered very incomplete and many have come to terms with some amount of noise, but is this normal? Furthermore, with default settings or not, I can’t change the amount of noise produced. Supposedly, using “progressively refine” in the rendering tab should make it refine itself indefinitely, however Cycles only counts to 10 refines and then stops, creating a render which is a pixel-perfect match of the ordinary rendering method when it’s completed.

I understand that there are tricks that can be used to reduce noise, but at the cost of extra processing time and usually small quality conflicts, like blurring. My question essentially boils down to is this Cycles’ current limit?



What you want is the number of Samples.

A Sample refers to cycles firing a “ray” into the scene and returning information based on the color and other properties of objects it interacts with.
E.g. If a ray bounces off a red object and then hits a light source, the corresponding pixel will get a red color.

Also see Why can’t cycles cast one ray per image pixel, instead of rendering progressively to infinity?

You can change the number of samples taken per pixel in Render settings > Sampling > Samples > Render:

enter image description here

Increase this value to take more samples and reduce noise. See the manual:

There are two integrator modes that can be used: path tracing and branched path tracing. The path tracing integrator is a pure path tracer; at each hit it will bounce light in one direction and pick one light to receive lighting from. This makes each individual sample faster to compute, but will typically require more samples to clean up the noise.

Progressive refine:

Progressive refine does not change the number of samples, it disables tiled rendering. With tiled rendering each tile is rendered to the full number of samples before starting the next. Disabling this is useful for rendering the entire image all at once, so the user can manually stop the render and get a finished image.

Note that the render will still stop at the number of samples defined in Sampling > Samples > Render using this setting, and rendering the entire image this way is much slower than rendering with tiles.

Source : Link , Question Author : person27 , Answer Author : Timaroberts

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