HdMoonRay Render Settings

This page describes the render settings supported by HdMoonray. The way these are set depends on the host application:

  • In usdview choose View/Render Settings.
  • In Houdini the “eye” button in the viewer lower-right brings up a control panel and these are on the first tab.
  • In Maya a control panel is brought up by clicking the empty box to the right of MoonRay in the Renderers menu on the viewer.

The default value for each option can be changed by setting an environment variable.

Use Remote Hosts

Type: Bool

Default: False

Environment Variable: $HDMOONRAY_HOSTS > 0

Description: When this is turned on, hdMoonRay will render using one or more hosts taken from the Arras pool, instead of running on your local machine. This can reduce the load on the local machine, and resolve to a final image much more quickly if multiple remote hosts are used. You should check the availability of Arras hosts before using this. This option has no effect in debug mode.

Remote Hosts

Type: Int

Default: 5

Environment Variable: $HDMOONRAY_HOSTS=n

Description: Sets the number of remote hosts to use. Shading will be faster roughly in proportion to the number of hosts you use, although the initial “render prep” stage, before shading begins, will remain roughly the same. Check the number of available Arras hosts before using this, since selecting more than are currently available will cause renders to fail. This option has no effect if “Use Remote Hosts” is off.

Max FPS

Type: Float

Default: 12

Environment Variable:

Description: This option sets the maximum number of image updates per second that MoonRay will provide during shading. It doesn’t affect the speed of the render, just how often it updates the display with the latest image. Normally you shouldn’t need to change this : it might sometimes be useful to turn it lower in order to reduce network traffic when using remote hosts.

Debug Mode

Type: Bool

Default: False

Environment Variable: $HDMOONRAY_DEBUG_MODE=1

Description: This switch turns on an alternate mode that can be used to help track down bugs or performance issues. It works by loading MoonRay directly into the application process. We don’t recommend turning this option on for normal use. Some features don’t work in developer mode, including remote hosts and pausing the render. If MoonRay asserts or crashes in developer mode, the entire application will exit.

Disable Render

Type: Bool

Default: False

Environment Variable: $HDMOONRAY_DISABLE=1

Description: Disables actual rendering, so that we can measure the performance of Hydra and the construction of the RDL SceneContext separately from the renderer.

Restart (toggle)

Type: Bool

Default: False

Environment Variable:

Description: This is a toggle switch that has an effect each time you click it (Hydra doesn’t support plain buttons in renderer settings : a toggle is the only way to get the same behavior). When you switch it, hdMoonRay shuts down the renderer and restarts it from scratch. It also allows you to retry a failed Remote Hosts setup. This option has no effect other than to reload textures in debug mode.

Reload Textures (toggle)

Type: Bool

Default: False

Environment Variable:

Description: Switching this forces MoonRay to re-read all texture files from disk.

Show Debug Messages

Type: Bool

Default: False

Environment Variable: $HDMOONRAY_DEBUG=1

Description: Enables printing of debug messages to the console. Turning this on will display a large number of debugging messages from MoonRay and hdMoonRay.

Show Info Messages

Type: Bool

Default: False

Environment Variable: $HDMOONRAY_INFO=1

Description: Enables printing of info messages to the console. This shows a smaller set of messages than “Show Debug”, but includes the MoonRay render summary.

Log Level (1-5)

Type: Int

Default: 1

Environment Variable: $HDMOONRAY_LOGLEVEL=n

Description: Sets how many debug messages to show from the remote hosts (or the single local host when not in debug mode)

Rdla Output

Type: String

Default:

Environment Variable: $HDMOONRAY_RDLA_OUTPUT=name

Description: Write the SceneContext as rdla. The file is written whenever the value of this option changes. Use “foo.rdla” to write an rdla file, “foo.rdlb” to write an rdlb file, or just “foo” to write both an rdla and rdlb, split so all the heavy binary data is in the rdlb, but the structure can be seen in the rdla.

Disable Lighting

Type: Bool

Default: False

Environment Variable: $HDMOONRAY_DOUBLESIDED=1

Description: Ignore any lights in the scene, and render it with the default dome light. This is used to implement the light on/off button in Houdini. Usdview has other methods of turning off all the lights that work as well.

Double Sided

Type: Bool

Default: True

Environment Variable: $HDMOONRAY_DISABLE_LIGHTING=1

Description: When this is on, all geometry is treated as double-sided, and to get single sided set int primvars:moonray:side_type = 1. When this is off standard USD behavior is used, where everything is single-sided unless bool doubleSided = true.

Denoising

Type: Bool

Default: False

Environment Variable: $HDMOONRAY_ENABLE_DENOISE=1

Description: Enables the Optix denoiser which will denoise the rendered image. Denoising does not currently work with debug mode.

Denoise : Albedo Guiding

Type: Bool

Default: False

Environment Variable: $HDMOONRAY_DENOISE_ALBEDO_GUIDING=0

Description: When Optix denoising is enabled this uses the albedo to guide it.

Denoise : Normal Guiding

Type: Bool

Default: False

Environment Variable: $HDMOONRAY_DENOISE_NORMAL_GUIDING=0

Description: When Optix denoising is enabled this uses the normal to guide it.