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

Timeout prevention

Iray Photoreal in CUDA mode uses the GPUs in a system to perform rendering. One or more GPUs are often also used to drive the main display device displaying the desktop and applications. On some operating systems CUDA kernel executions are not allowed to exceed a specific amount of time to avoid having an unresponsive user interface.

If a CUDA kernel execution exceeds this limit the operating system may interpret the call as stalled and may restart the driver. To avoid this, Iray Photoreal incorporates a mechanism to automatically adjust the task sizes of GPU function calls, i.e., the total rendering payload per step is divided into smaller fragments depending on the efficiency of the CUDA device on the given scene.