Iray Programmer's Manual

Preface
Getting started
- Release overview
- Example programs
- How to compile a program
- How to run a program
- Starting and shutting down the Iray API
- A first image
Library design
- API modules
- Shared library
- Naming conventions
- Include files
- Include file compile-time configuration
- Main API access point
- Version numbers and compatibility
- Interfaces
- Reference counting
- Handle class
- Resources
- Strings
- Error handling
- Database, transactions and scopes
  - Transactions
  - Database scopes
- Runtime configuration
Rendering
- Rendering overview
- Rendering and canvases
- Render mode selection
- Progressive rendering of a scene
- Own canvas class
- Asynchronous rendering
- Multiple render contexts
Iray Photoreal
- Introduction
- System requirements
- Limitations
- Matte objects and matte lights
- Refractive objects and IOR handling
- Progressive rendering
- Caustic sampler
- Architectural sampler
- Light portals
- Rendering options
- Mixed mode rendering and load balancing
- Timeout prevention
- Integrated noise reduction
- Integrated bloom
Iray Interactive
- Introduction
- System requirements
- Limitations
- Progressive rendering
- Lighting
- Rendering options
- Path space filtering
- Output format
- Global performance settings
- Comparison with Iray Photoreal
Iray Realtime
- Introduction
- System requirements
- Limitations
- Rendering options
Iray Blend
- Introduction
- Rendering options
Scene database
- Overview of the scene database elements
- Creating a scene programmatically
Geometry
- Creating triangle meshes
- Creating polygon meshes
- Creating on-demand meshes
- Creating subdivision surfaces
- Creating freeform surfaces
Materials
- Material Definition Language
- Measured materials
- Editing and creating materials
Decals
Sources of light
- Emission distribution functions
- Light distribution from scene elements
Environment dome and implicit groundplane
- Environment function
- Environment dome
- Implicit groundplane
Camera
- Tonemapping
  - Photographic tonemapper
  - Custom tonemapper
- Depth of field
- Virtual backplate
- Motion blur
Physically plausible scene setup
- Recommendations for geometry preparation
- Recommendations for lights
  - Using photometric lights
  - Using environment and sunlight
- Recommendations for materials
- Recommendations for cameras
Networking
- Networking overview
- Networking modes
- Iray Bridge
Delivering an image from server-based rendering
- Running an HTTP server
- RTMP server
- RTMP client
- Running an RTMP and HTTP server with mouse interaction
Customization
- Extending the database with user-defined classes
- Extending neuray with plugins
- Extending supported file formats with plugins
Appendix
- Supported file formats and URI schemes
- Result canvas names
- Light path expression grammar
Bibliography

Mixed mode rendering and load balancing

Generally, Iray Photoreal uses all available CPU and GPU resources by default. Iray Photoreal employs a dynamic load balancing scheme that aims at making optimal use of a heterogeneous set of compute units. This includes balancing work to GPUs with different performance characteristics and control over the use of a display GPU.

The following key-value pairs, shown here with their default settings, control rendering when passed to mi::neuraylib::IRender_context::set_option():

mi::Float32 ui_responsiveness = 1.f/6.f: Using the device that drives the screen for rendering with Iray may lead to sluggish UI updates. This can be ameliorated by increasing the value of the ui_responsiveness option, up to a maximum of 1 . Note, however, that increased UI framerate may come at the cost of severely decreased rendering performance on display devices.

Note: Currently, this option is supported on Windows only.

For details about:

Controlling resource use, see mi::neuraylib::IRendering_configuration::set_resource_enabled()
Resource scheduling modes, see Progressive rendering in Iray Photoreal