What’s Included?

The open source release contains the following pieces of technology:

  • MoonRay: path-tracing renderer
  • Scene Object Classes: (materials, geometry, lights, cameras, etc) used at Dreamworks Animation (about 150 in total)
  • HdMoonRay: the hydra plugin for MoonRay
  • Arras: execution and distribution framework, used to integrate MoonRay into applications as well as provide multi-machine rendering

The source is contained in multiple Git repositories. The openmoonray repository contains the top-level CMake build files, and uses submodules to link in all the others. The zipped source release is the openmoonray repository with the submodules filled in.

MoonRay

Three Git repositories make up the main source of MoonRay, providing the command line renderer and libraries used to integrate MoonRay and author scene objects:

  • scene_rdl2 provides the RDL2 scene description format used by MoonRay. The in-memory format is called SceneContext. scene_rdl2 can read and write SceneContexts in two file formats: RDLA and RDLB.
  • mcrt_denoise contains the implementation of the MoonRay denoiser.
  • moonray is the main implemention of the renderer, and depends on the previous two repositories.

moonray_gui contains an interactive Qt application that performs a render and displays the frame buffer as the render progresses.

Scene classes

The moonray repository contains a basic set of of scene class plugins for use with MoonRay. The moonshine repository contains an additional set of scene classes.

 
Camera
Bake, DomeMaster3D, Orthographic, Perspective, Spherical
Displacement
Combine, Normal, Vector, Switch
Display filter
Blend, Constant, Halftone, Ramp, Shadow, Clamp, Convolution, Image, Remap, TangentSpace, Discretize, Op, RgbToFloat, Toon, ColorCorrect, Dof, Over, RgbToHsv
Geometry
OpenVdb, RdlCurve, RdlInstancer, RdlMesh, RdlPoint, Box, Sphere, Template
Light
Cylinder, Disk, Distant, Env, Mesh, Rect, Sphere, Spot
Light Filter
BarnDoor, ColorRamp, Cookie, Intensity, Vdb, Combine, Decay, Rod
Map
Attribute, Debug, List, UsdPrimvarReader_float2, UsdPrimvarReader_point, UsdUVTexture, Checkerboard, ExtraAov, OpenVdb, UsdPrimvarReader_float3, UsdPrimvarReader_vector, Image, UsdPrimvarReader_float, UsdPrimvarReader_int, UsdTransform2d, AxisAngle, ColorCorrectLegacy, Directional, LOD, ProjectSpherical, SwitchColor, Blend, ColorCorrect, FloatToRgb, Noise, ProjectTriplanar, SwitchFloat, Clamp, ColorCorrectNuke, Gradient, NoiseWorley, ProjectTriplanarUdim, Template, ColorCorrectSaturation, HairColorPresets, NormalToRgb, Ramp, Toon, ColorCorrectContrast, ColorCorrectTMI, HairColumn, Op, Random, TransformNormal, ColorCorrectGainOffset, ConstantColor, Hair, OpSqrt, Remap, TransformSpace, ColorCorrectGamma, ConstantScalar, HsvToRgb, ProjectCamera, RgbToFloat, UVTransform, ColorCorrectHsv, Curvature, Layer, ProjectCylindrical, RgbToHsv, Wireframe, ColorCorrectHueShift, Deformation, LcToRgb, ProjectPlanar, RgbToLab
Normal Map
Distort, ProjectCamera, ProjectTriplanar, RgbToNormal, UsdPrimvarReader_normal, Combine, Image, ProjectPlanar, Random, Switch
Material
Axf, Base, Measured, RaySwitch, Switch, UsdPreviewSurface, *DwaColorCorrect, DwaLayer, DwaRefractive, DwaSwitch, GlitterFlake, HairDiffuse, Toon, HairToon, DwaAdjust, DwaEmissive, DwaMetal, DwaSkin, DwaTwoSided, Hair, HairLayer, DwaBase, DwaFabric, DwaMix, DwaSolidDielectric, DwaVelvet, HairColorCorrect, MacroFlake
Volume
Base, Cutout

The moonshine_usd repository contains two geometry classes : Usd and UsdInstance.

HdMoonRay Hydra Plugin

The hdMoonRay repository contains the MoonRay Hydra render delegate plugin and several adapter plugins for the USD scene delegate. The adapter plugins are needed to work around missing support in earlier versions of the USD scene delegate, and should no longer be necessary as Hydra evolves.

The MoonRay material and map shader classes need to be registered with the USD SDR library to use MoonRay material networks. This is done with two plugins in moonray_sdr_plugins. These plugins read JSON descriptions of the shaders from MOONRAY_CLASS_PATH. The JSON files are not built by the MoonRay cmake system : you will need to generate them using the rdl2_json_exporter program before using HdMoonRay for the first time.

HdMoonRay requires Arras to build and run.

There are more instructions on how to configure and use HdMoonRay in the Hydra plugin README file (hydra/README.md) and here.

Arras

Arras allows applications to use the MoonRay renderer running in one or more separate processes. Arras itself is not specific to MoonRay, and can be used to run other programs.

The arras4_core repository contains C++ interfaces and implementations of the central Arras components. It contains everything needed to create and run Arras components in local mode (in a single process on the same machine as the client).

moonray_arras (under the moonray top-level directory) contains the MoonRay-specific Arras components:

  • mcrt_messages defines the Arras messages used to communicate between client and render processes.
  • mcrt_computation contains the Arras computations that execute MoonRay rendering under Arras.
  • mcrt_dataio contains code to decode rendered images and to merge partially rendered images, required by both client and render processes.

The arras/distributed directory holds the components needed to run distributed Arras renders:

  • arras4_node runs on every render node
  • a single instance of minicoord is run as a service to allocate and manage render nodes

arras_render is a GUI tool to execute Arras renders, and provides an example of Arras integration.