Arnold Rendering Configurations

Here are some notes I think.

  • The rendering configurations of the Arnold should be changed from the default values.
  • The configurations if you changed but I think it should be changed back to default.

Thread configuration

You can change the number of threads assigned to tune-up the performance of UI response while the Arnold renders the viewport. The number of usable threads changed by the CPU capability, but you can increment it if you use recent CPU.

Change the Arnold RenderView configurations

Change the value to 2 or 3 from the default value 1 by doing as follow.

  1. Select the “Open Arnold RenderView” from the “Arnold” menu.
  2. Select the item “2” or “3” in “Save UI Threads” submenu of “Renderer” menu in the “Arnold RenderView” window.
Change the number of the User interface threads in Arnold RenderView window.
Change the number of the User interface threads in Arnold RenderView window.

Change the viewport configurations

You can also increment the number of threas for the viewport.

  1. Select the “Arnold” from the “Render” menu in the viewport.
  2. Select the item “2” or “3” in the “Save UI Threads” submenu of the “Render” menu in the “Arnold ViewportRenderer Options” window.
Change the number of UI threads for the viewport
Change the number of UI threads for the viewport

The configuration for the Arnold Renderview will be saved

You may think the configuration will be saved because the menu item title contains the “Save” word, but after relaunched app, the configuration for the Arnold Renderview was restored but not for the viewport. The configuration for the viewport was reverted to “1”, it is default value. I saw this in the Maya 2023. In the future, this issue would be fixed I hope.

Adaptive Rendering

The Adaptive Rendering function can change the Camera AA (Sampling) value from place to place. It can keep the quality as high AA value and may reduce the rendering time. But it seems that it depending on the rendering target, it may take more time, so you should not always turn on this configuration.

To turn on the Adapative Rendering, do following.

  1. Turn on the “Enable” check box of “Adaptive Sampling” in the “Arnold Renderer” tab in the “Render Settings” window.
  2. Enter the max Camera AA value into the “Max. Camera (AA)” field and the minimum value into the “Camera AA” of the “Sampling”. For example, you would like to change the value from 3 to 10, you should enter the “10” into the “Max. Camera (AA)” and “3” into the “Camera AA”.
  3. Increment the value of “Adaptive Threshold”. The best value is depending on the image so you need adjust it with the rendering results. The default value is a high quality but the rendering time is long.
Example of the rendering configurations
Example of the rendering configurations

The rendering format

I think the exr is the better rendering format than others. The exr supports the high dynamic range. For the details about the format, please check other web sites.

If the data size is a big, its file size to be big too. With the “Half Precision” option, the data accuracy to be half and you can reduce the data size. On the screen, the difference can’t be recognize by eyes. The “Half Precision” option is available in the “File Output” in the “Common” tabl in the “Render Settings”.

This option is displayed after change the “Image format” to the exr.

Half Precision Option
Half Precision Option

Compare the results of the Half Precision option

I compared the result of the Half Precision option. The image size if HD_1080 (1920×1080).

Both of the file size is below:

  • Half Precision On : 4.06MB
  • Half Precision Off : 1.51MB

Both of them with the zip compression option, but the file size was dramatically changed.

I opened with Photoshop and see them, I could find any differences.

Calculated the difference of two images with the Photoshop function, but the difference was not reported.

I think, it is depending on the image but almost of cases are no problem.

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Author of this article

Akira Hayashiのアバター Akira Hayashi Representative, Software Engineer

I am an application developer loves programming. This blog is a tech blog, its articles are learning notes. In my work, I mainly focus on desktop and mobile application development, but I also write technical books and teach seminars. The websites of my work and books are here -> RK Kaihatsu.