A Simple-Image Renderer
(c) 2000 J. Scott Iverson
Siren is a scanline implementation of the RenderMan standard for describing
3D scenes. It renders simple scenes well. It supports most
of the basic RenderMan functionality and provides many of the optional
capabilities described in the RenderMan standard. Siren runs under
Siren supports the following required RenderMan features:
Siren supports the following optional capabilities described in the RenderMan
Hierarchical graphics state
Orthographic and perspective projections
Depth-based hidden surface removal
Pixel filtering and anti-aliasing
Gamma correction and dithering
File output containing RGB, A and Z data
All geometric primitives described in the specification
The fourteen standard light source, surface, volume, and displacement shaders
required by the specification.
Level of Detail
Motion Blur (including correctly interpolated rotation)
Depth of Field
Shadow Depth Mapping
Siren makes it easy to animate almost any aspect of a scene quickly, including
lighting, shading and object placement. It invites experimentation.
renders simple scenes in real time for motion preview
can record a series of frames as a FLIC animation file
provides extensive support for using motion blocks to define key-frame
animation. Almost any RIB command can be placed within a motion block
(with no restriction on the number of times) and any floating-point parameters
will be correctly interpolated. Siren will blur moving transformations
and time-varying shaders.
provides a Shading Language interface to RIB via a new type of shader -
procedure shaders - which can issue any RIB call.
Veteran RenderMan users are encouraged to read the documentation and
to work through the brief introductory tutorial, since Siren functions
somewhat differently than other renderers.
Siren is still very much a work in progress, even though it's existed
in various forms for about 10 years. I originally wrote it for my
own exploration of 3D graphics. Hopefully it's now reached the stage
where others will find it useful. Suggestions for improvements and
changes are welcome. If you do something interesting
Siren software and documentation are Copyright 2000 J. Scott Iverson.
All rights reserved.
with Siren, let me know.
The RenderMan (R) Interface Procedures and RIB Protocol are Copyright
1988, 1989, Pixar. All rights reserved.
RenderMan (R) is a registered trademark of Pixar.
Last Modified March 31, 2000
Send questions, comments, and bug reports to: firstname.lastname@example.org