Shader Writing and Integration

Since the miOptions data structure, and the methods for accessing frame buffers have changed, all shaders that use the geometry shader interface must at least be recompiled. All output shaders need to be modified and recompiled.

• New modes for mi_query were added:
  miQ_INST_FINALGATHER
  miQ_INST_PLACEHOLDER_ITEM
  miQ_OBJ_FINALGATHER
  miQ_SCENE_ROOT_GROUP
  miQ_TEXTURE_DIM
  
  
• Here is the preliminary list of new shader and integration interface functions:
  

  mi_api_colorprofile_begin
  mi_api_colorprofile_end
  mi_api_colorprofile_space
  mi_api_colorprofile_white
  mi_api_data_callback
  mi_api_object_placeholder_callback
  mi_api_output_colorprofile
  mi_api_primlist_approx
  mi_api_primlist_begin
  mi_api_primlist_border
  mi_api_primlist_dimensions
  mi_api_primlist_end
  mi_api_primlist_topology
  mi_api_texture_callback_def
  mi_call_contour_material
  mi_colorprofile_ciexyz_id
  mi_colorprofile_ciexyz_to_internal
  mi_colorprofile_ciexyz_to_render
  mi_colorprofile_internal_to_ciexyz
  mi_colorprofile_internal_to_render
  mi_colorprofile_internalspace_id
  mi_colorprofile_render_to_ciexyz
  mi_colorprofile_render_to_internal
  mi_colorprofile_renderspace_id
  mi_continue_shadow_seg
  mi_disp_fbmap
  mi_disp_fbunmap
  mi_mem_set_flush_failure_cb()
  mi_msg_pipe_mode_enabled()
  mi_output_image_close
  mi_output_image_open
  mi_reflection_dir_anisglossy_x
  mi_reflection_dir_diffuse_x
  mi_reflection_dir_glossy_x
  mi_texture_interpolate
  mi_transmission_dir_anisglossy_x
  mi_transmission_dir_diffuse_x
  mi_transmission_dir_glossy_x

• The image pointer has been removed from the options. Output shaders must call mi_output_image_open and mi_output_image_close for frame buffer access.
• The fields image_types, write_image and interp_image have been removed from the options. Frame buffers are now specified in a database array of type miFb_info, which is field images_info in the options.
• The callback installed by the mi_disp_stream_cb_begin integration function receives a pointer of type miRc_mapfb instead of a tag array referring to miImg_image elements. A frame buffer can be accessed from the callback by using mi_disp_fbmap and mi_disp_fbunmap.
• The mi_query mode miRCQ_IMAGE has been removed. A new mode miRCQ_FB has been introduced that allows access to frame buffers. mi_rc_run_query returns a pointer of type miRc_mapfb for this mode, which can be passed to mi_disp_fbmap and mi_disp_fbunmap for frame buffer access.
• Incompatible changes to the miInstance and miObject data structures have been made. The trace field has been removed, reflection, refraction, it transparency and finalgather fields have been added. The shadow field is no longer treated as a boolean, it is interpreted as a bitmap which controls casting and receiving separately.
• state->face is initialized with zero instead of using the value defined in the global options, allowing mental ray to distinguish between face flags set in the options, in the object or instance or overridden by the shader.
• Some obsolete fields in the miGeoBox data structure have been removed.
• For integrators, a new approximation style miAPPROX_STYLE_FINE_CONT_DISP has been added to the integration API. It enables the continuous displacement of unshared vertices for displaced polygons.
• The implementation of the mi_noise_... utility functions for shaders has been improved. Note that this change may have a large effect on existing setups using noise.
• Integrators must now call mi_api_texture_file_size() with the value miIMG_TYPE_ANY instead of 0 as the fourth argument in order to keep the old behaviour. This change is caused by added controls for light map creation.
• The function mi_api_object_placeholder_callback has been added as an alternative to mi_api_object_callback.
• For integrators, a macro miBOX_BORDER_MATERIAL() has been added to facilitate access to the materials at borders.
• The mi_rc_run_query mode miRCQ_NEEDS_PREPROC has been added.

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