Keywords: main

Next: 6.3 Shader Writing Up: 6. Upgrading from mental Previous: 6.1 Rendering Algorithms

# 6.2 Scene Description Language

mental ray 2.x supports a new generation of the mental images scene description language, called `.mi2`. The language version supported by mental ray 1.9, called `.mi1`, is still available for backwards compatibility. New translator designs should always use `.mi2` because only `.mi2` supports instancing, inheritance, incremental changes, and many other features. Here are some rules for using `.mi2`:

- Use object space coordinates instead of camera coordinates.

- Use options, cameras, instances and groups instead of frames and views.

- Use incremental changes wherever possible.

- Do not use the following statements: `red`, `green`, `blue`, `white`, `recursive`, `adaptive`, `memory`.

- Double-quote names to avoid clashes with new keywords.

- Contour rendering has been rewritten completely. The new algorithms offer much higher flexibility, programmability, and features such as colored contours, varying line widths and styles, parallelism, and contour generation concurrently with color image generation, and compositing. The contour modes of mental ray 1.9 are no longer supported, any `.mi1` scene file containing contour features must be modified.

- Use `contour contrast`, `contour store`, `contour output`, and contour shaders.

- Do not use: `contour line width`, `contour depth`, and `paper transform`.

Next: 6.3 Shader Writing Up: 6. Upgrading from mental Previous: 6.1 Rendering Algorithms