Default

-- Render Settings

Clay Render- Enables Clay Render
Renders all materials with a White Diffuse Material

Smooth Normals - Enter the amount of smoothing for the selected object
Everything is hard edged by default in the YafaRay renderer

Input Color Space - Color processing types for all textures:

- Denoise Settings -

Denoise - Enables Denoise
Chrominance - Color Noise control
Luminance - Brightness Noise control
Mix - Proportion of Denoise and original image

- Draw Parameter -

Log Draw Parameter - Logs rendered results to a html file where you rendered the image.
Enter comments that appears in the html file.

- Bucket Rendering -

Tile Order

Tile Size - Size of the tiles used for rendering

Save Time
- Number of seconds between partial render saves.

Off/On - Off sets the Save Time to 0. On sets the Save Time to 6.
Can be used to observe a long render to see if things are going well.
Results during the render can be seen in Windows Explorer and in the optional OptDetector Viewer.
Do not set too low because your machine may not be able to save quickly enough.
Important: Set to zero to stop the timer.

Open Render Pass - Select this button to Open/Close the Render Pass floating panel.

- Scene Settings -

Scene Brightness - Alters the D3D light's Attenuation to match YafaRay renders
Open Scene Utilities - Set of tools for processing scenes to get them ready for sharing and rendering.
Make Names Unique - renames renderable items that have the same name to avoid material definition clashes.

-- Output Render File --

View - If enabled YafaRay will render the Workspace view.
Camera - If enabled YafaRay will render the set Camera view.
Width - The width of the image rendered.
Height - The height of the image rendered.
> File name for rendered image output. This is where the rendered results will be saved.
Open Output Folder - Opens the folder entered into the above path.
Render - Exports XML file and spawns the YafaRay renderer.

YafaRay Official Docs Render Settings