Shader Writing and Integration

• Shaders can now define thread local shader storage, to replace the simple method of indexing an array with a thread number, which worked in mental ray 2.1 but not 3.x. See page shadertls for details.
• The mi_trace_probe shader interface function in mental ray 3.1 finds objects with any flags, including visible and shadow; mental ray 3.2 will probe only objects marked trace. The state type is miTRACE_PROBE.
• High Dynamic Range images allow more compact storage of RGB color values greater than 1.0.
• IES and Eulumdat light profiles are supported. There is a new lightprofile ... lightprofile end block, and a new lightprofile shader parameter type. Light profile data can be passed to shaders in a similar way to user data. New mi_query modes, mi_api_lightprofile_* geometry shader API functions, and mi_lightprofile_* shader interface functions were introduced.
• Image streaming, which is part of the mental ray integration interface, has changed.
• Slave hosts can be added and removed at any time between frames, instead of using a list fixed at startup time, using the mi_msg_add_host and mi_msg_remove_host.
• New modes for mi_query were added:
  
  miQ_FUNC_TLS_GET
  
  miQ_FUNC_TLS_GETALL
  
  miQ_FUNC_TLS_SET
  
  miQ_LIGHTPROFILE_COSTHETA_MAX
  
  miQ_LIGHTPROFILE_COSTHETA_MIN
  
  miQ_LIGHTPROFILE_INTENSITY_MAX
  
  miQ_LIGHTPROFILE_PHI_MAX
  
  miQ_LIGHTPROFILE_PHI_MIN
  
  miQ_LIGHTPROFILE_PHI_RES
  
  miQ_LIGHTPROFILE_THETA_RES
  
  miQ_LIGHT_CAUSTIC_PHOTONS_EMIT
  
  miQ_LIGHT_GLOBAL_PHOTONS_EMIT
  
  
• Here is the complete list of new shader and integration interface functions:
  
  mi_api_hair_begin
  
  mi_api_hair_end
  
  mi_api_hair_hairs_add
  
  mi_api_hair_hairs_begin
  
  mi_api_hair_hairs_end
  
  mi_api_hair_info
  
  mi_api_hair_scalars_begin
  
  mi_api_hair_scalars_end
  
  mi_lightprofile_sample
  
  mi_lightprofile_value
  
  mi_msg_remove_host
  
  mi_renderpass_access
  
  mi_volume_instances