TYPE: ROP
TITLE: Archive Generator ROP

This output operator can be used to generate archives which can be
used by either mantra or RIB renderers.  Archives allow Houdini to be
more efficient when generating scripts for renderers since:
    a)  Houdini can have different geometry displayed
    b)  Houdini doesn't have to send the geometry down to the renderer
        every frame.

Mantra archives are stored as simple geometry files.  Typically, these
should be .bgeo files.

RenderMan archives will contain geometry exactly as it would appear in
a RIB file generated by the RenderMan output driver.  This means that
sub-division surfaces, curves, points etc. will be output rather than
the default geometry saved by .geo to .rib conversion.

Arguments may be passed to the script and variable expansion is done
before calling the script.

Parameters:
    Render               - Begins generation of archives
    Frame Range          - Generate archives for multiple frames
    Renderer             - Which renderer the archives are intended for
    Camera               - When generating RIB archives, motion blur
                           can be "baked" into the archive.  The
                           motion blur parameters are picked up from
                           the camera.
    Visible Objects      - List of objects which should be included in
                           the archive.  When generating mantra
                           archives, all objects are merged into a
                           single .bgeo file.  Care must be taken with
                           regards to differing attributes in
                           different geometries.
    Unload SOPs          - Unload SOP geometry after used by the render
    Transform Object     - This field specifies the "origin" or "frame
                           of reference" that all objects in the
                           archive will be relative to.  If the field
                           is left blank, objects will be output
                           relative to the world origin.
    Use Display SOP      - Use the display SOP instead of the Render SOP
    Initialize Simulation SOPs - force all simulation SOPs to be reset.
    Binary Script        - Outputs binary files where possible.
    Script File          - Filename of the archive to create.
    Motion Blur          - The default motion blur for rendering.
                           This can be overridden by an individual object.
                           Currently, this is only implemented for RIB
                           files, since mantra will blur between
                           multiple geometry files with deformation
                           blur (or use the velocity attribute stored
                           in the geometry file if required).

    Mantra SHOP References  - Hardening SHOP references will cause the
                           shader strings associated with the SHOP to
                           be evaluated and stored in the archive.
                           If the SHOP references variables like $OBJ,
                           this may be required.

                           NOTE:  Point attribute indirect references
                           are handled differently and are not
                           considered when de-referencing indirect
                           SHOPs.

    RIB Version          - Output RIB for the target version of RIB
    RIB Allow Nested Archives - If an object chosen is set to render
                           using an archive, nesting archives will
                           output the referenced archive into the
                           created archive.  If this option is turned
                           off, then the geometry for the object will
                           be output instead.
    RIB RiCurve Basis    - Curve bases used for generating open polygons.

    Pre-Render Script    - Execute this script before any rendering.
    Pre-Frame Script     - Execute this script before each frame
    Post-Frame Script    - Execute this script after each frame
    Post-Render Script   - Execute this script after all rendering

Local Variables:
    N        - The current frame of the range specified.  This always
               starts at 1.
    NRENDER  - Total number of frames being rendered.

See also: Mantra(mantra), RenderMan(rman)
