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Notes from SIGGRAPH 2001
By Jeremy Birn
Los Angeles, August 17, 2001 - The Exhibition area seemed small this year, with fewer booths than previous years, and fewer attendees. Nonetheless, the courses, papers, parties, and other parts of the conference were as good as ever, and there were some noteworthy new products to see on the show floor. |
Being a Renderman-compliant renderer, people could already use Entropy with most leading 3D animation software, or any program that can output .rib files. However, coming with a quick, easy, graphical interface, and adding support for the existing shaders and parameters from Max (plus some others including their own hair shader), Entropy seems certain to be an appealing option to a broad range of customers. Entropy 3.1 for Max is $1,500, including the GUI for Max and a rendering license for 2 CPUs, and will be available in the forth quarter of 2001. Exluna has also announced a partnership with Alias|Wavefront, but could not give any timetable for when the Maya version of their graphical interface would be released. |
A few background notes are in order on Renderman and BMRT: Pixar sells their own rendering software, Pixar's Photorealistic Renderman (PRM), which is now used to render the majority of feature film effects and animation shots produced by major studios. PRM is a scanline renderer without raytracing, and costs over $5000 per processor, but it can quickly render complex, high-geometry scenes at high resolutions, with pixel-level displacement mapping and motion blur, meeting the needs of studios rendering feature film shots. Besides their renderer, Pixar also created a "Renderman standard" in the hopes of creating an industry standard between different animation software, rendering software, and renderfarms. Any Renderman-compliant renderer can read .rib (Renderman Interface Bytestream) files as a standard 3D scene description language. Another Renderman-compliant renderer is Blue Moon Rendering Tools (BMRT), which Larry Gritz wrote as a thesis project. BMRT supports raytracing and global illumination functions not supported by PRM, and is available for free download from BMRT.org, but is of limited use in production because it renders somewhat slowly. BMRT has played a small supporting role in some feature films, used selectively where raytracing was needed in particular shots. BMRT author Larry Gritz worked several years at Pixar, leading their rendering research group, and is also the co-author of the book Advanced Renderman : Creating Cgi for Motion Pictures. Over a year ago, Gritz left Pixar and started his own software company, Ex Luna, along with some other notable programmers, to develop their new Entropy renderer. |
Maya's renderer continues to improve every version, even core features are getting re-written. After last year getting new (much better) displacement mapping, in Maya 4 the new bump mapping produces much better quality of shading than the old bump mapping. In a much-requested new feature, Maya 4 finally gives you separate "Emit Diffuse" and "Emit Specular" controls on each light. Even with recent improvements, the renderer is still an area where a continued development focus is needed on Alias|Wavefront's part. While Maya 4.0 might not boast as many flashy new features as some previous releases, it shows that Alias|Wavefront has the right priorities. Maya already has lots of cool features like Paint Effects that give it more bells and whistles than competing programs, and seems poised to add more cool features like fluid and fire simulation in Maya 4.5. Right now, most users are really depending on much more basic functions in daily production work. The small workflow improvements and fixes being added in Maya 4 are right on target for helping existing users with their work. Also laudable at the Alias|Wavefront booth, as shown in the picture above, was seeing Maya running on Mac OS X. |
So, if you are a Maya user, what are your rendering options? The most popular alternative renderer for Maya is Pixar's Photorealistic Renderman - in fact, the old Mantra from the 90s of "Model in Alias, Animate in Softimage, Render in Renderman" has been largely replaced by the current approach of most leading studios, "Model and animate in Maya, Render in Renderman." While the price may be high per CPU, the faster rendering means that fewer computers can outperform a larger render farm that only had the Maya renderer, and the extra quality and creative control can add to your final output. With Pixar's Renderman Artist's Tools (RAT) package, you can control it all from within Maya, without any need to edit scripts, shaders, or rib files in a text editor. Entropy (from Exluna, described above) could certainly be worth waiting for as well, if it will be only 25% the price of PRM, and will provide more features such as raytracing, global illumination, and motion blurred shadows. In fact, using MayaMan from Animal Logic, you could use Entropy without waiting for ExLuna to make a Maya-specific GUI. Jig, from Steamboat Software is another alternative for Maya rendering. At SIGGRAPH, Steamboat was demonstrating Jiggy, their new plug-in GUI for launching Jig renderings from within Maya. Jig is available for $1,500 including the Jiggy interface for Maya. Alias|Wavefront is also working on bringing Mental Ray to Maya. Because A|W can add Mental Ray support directly into Maya, instead of having to work through their own API, we can expect very good integration with the Maya interface when that becomes available. |
In the Start-Up Park, Spheron was demonstrating a cool new digital camera that captures High Dynamic Range Images (HDRI) Panoramas, running a full 360 degrees around and almost 180 high. If your renderer can use HDRIs to light a scene, then this could allow you to match any environment's lighting with a 2-minute scan, as well as using the same scan for reflection maps. This looks like it could become standard rental equipment for acquiring HDRI lighting environments from film locations. | |
There are still several limiting factors to using HDRI as a source of diffuse lighting. Not every program has shaders to support HDRI. No commercial software does a good job of handling shadowing from spherical HDRI light sources (and without shadows, you'd only use the HDRI source as a replacement for ambient, not your primary lighting.) But the most serious problem is that most productions only use a lighting-match from a location as a starting point for the lighting on a CG character, then modify extensively from there - at present, editing an HDRI map around a character is slower and more difficult than moving a light. |
In the same year that the XSI 1.5 shipped, Softimage is showing XSI 2.0, slated to ship the end of October. XSI 2.0 corrects the worst of the holes that had remained in XSI 1.5, including a new API (electric rain was already advertising their Swift 3D plug-in that allows XSI 2.0 to render in EPS, Flash, and other vector formats), new text generation and EPS import tools, and Rendermap (the Softimage|3D tool that allows procedural textures to be baked into file textures, or for models to be pre-lit with illumination converted into texture maps.) XSI 2.0 also boasts Linux support, and interesting new Realtime Shaders that are animated dynamically in the shaded view. In the animation department, 2.0 also adds more high-level editing tools to the animation curve editor, easy blending of both Forward and Inverse Kinematics applied to the same parts of a character, and a new Synoptic View that turns user-defined images or diagrams into scriptable pop-up control panels that can be used for posing or picking parts of a character by clicking on areas of the image. Perhaps the most valuable new feature in XSI 2.0 is the new built-in compositing system with a process tree (node-based) interface. The compositor's realtime integration with the renderer allows your final composite to update with changes in the 3D scene, and it is so closely integrated that it even supports expressions that can use XSI scene variables to drive pixel-level image manipulations. |
A number of free extras round-out XSI 2.0: The new Hair and Fur is rendered through a Mental Ray geometry shader that makes actual geometry at rendertime, which would be a plus when it comes to shadowing, reflections, and motion blur (often missing in fur approaches based on volume rendering, particles, or post-process effects.) The new version of the Toon shaders looked much more full-featured, and are now nodes in the Render Tree, allowing many more hooks for fine-tuning or creating new non-realistic looks. Softimage is even kind enough to develop free Maya and Max plug-ins that export .xsi files, making it easier to move files into XSI (or into Softimage's freely downloadable .xsi viewer) from other applications. So, what will the future bring for Softimage? It's hard to say. Right now, Softimage has a good, competetive product, but very little market share - I look around town and see Maya at almost all the film studios, and mostly Max in game companies. If Avid sticks to its guns for another year or two, and keeps pulling out cool releases of XSI, then the market could be re-built. On the other hand, Softimage has been in a bad situation for over three years now, and at this point it seems as if everything needs to work out just right in order for them to pull through. While Softimage's development is obviously focused on the newer XSI generation of software, Softimage surprised its users at the User's Group Meeting by announcing that their venerable Softimage 3D line is actually getting a new version as well. Version 4.0 is slated to ship with new game features (thanks to partnership with Nintendo) and a full Linux port. At the Softimage Users' Group Meeting, ILM was showing some of the work that their animators had been doing recently in Softimage 3D. "At ILM, we're using the 'Classic' Softimage" explained ILM Technical Animation Supervisor Sylvia Wong, "The animators are very comfortable with it." |
SIGGRAPH (Special Interest Group on Graphics) is the leading American organization for computer graphics professionals. Visit siggraph.org for details about future conferences:
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Copyright © 2001 by Jeremy Birn. Please do not duplicate without written permission.