Justin Leach chronicles his experiences as 3D CG creator on Ghost in the Shell 2: Innocence in this informative production journal.

Softimage responded to users request with XSI4. Images courtesy of Softimage Co. and Avid Technology Inc., unless otherwise noted.


I. Review: SOFTIMAGE|XSI 4.0

Many of XSI 4.0s enhancements and features are a direct result of user requests, such as rigid body dynamics, goal based simulation, material libraries, texture layer editor, competitive pricing, mental ray 3.3 Python support, more rendering nodes and advanced UV unwrapping tools. Others were a very welcome surprise, such as vector/raster paint, construction modes, audio tools, custom display host, new XML based interface controls, complementary renderfarm software, character SDK, metashaders, Syflex cloth, Alienbrain support, Digimation support and Avid Mojo support.

1. The Interface

It still looks very much the same, but it now provides many new functions that were previously impossible, such as relational views and a new type of view that contains multiple views that work together as a team. They are very easy to make, as creating these views works much like building a layout for your interface. As an added bonus, the interface no longer hides buttons and controls when it is resized, and it is relatively easy to add commands to the right-click menu as well as the other existing menus. Other relevant novelties are, for example, the support for a dual monitor render window that is now possible to reorder scene objects in the explorer, minimize floating windows and to auto hide the interface. While previous versions of XSI had some ghosting ability, it was nothing like the new ghosting that has been implemented in XSI 4.0. With the new functions, you can ghost just about any animated function: hair, bones, cloth, softbodies, hardbodies, etc. It is tied to the architecture at a very core level and there are many more options that are waiting to be explored. And the custom display host is pretty amazing. It lets you open any foreign application (such as a game engine) in a viewport. This means that a game developer can now run and test the game directly within XSI. You can easily play the game and test it, using a joystick or the keyboard. It is even possible to run another 2D or 3D application within the XSI viewport. XSI layouts have been completely revamped, described in a simple XML file and are now resolution independent. Until XSI 3.5 you could create layouts, but you could not really modify panels. In version 4, you can split horizontal/vertical panels and add several components to it.

Avids digital nonlinear accelerator Mojo is a great enhancement. Credit: Britney Spears Toxic by KromA for Jive Records.


2. Modeling

XSI Bevel has been enhanced even more, making it easier than ever to bevel polygons, points and edges; also the beveling of text is now much easier. A new tool called manage collisions makes it a snap to collapse points that collide with each other during the bevel process. There are new knife features, which work much like the knife tool in LightWave. One is called knifing and the other is called slicing. They perform the same operation, allowing you to split the polygons of a mesh object along any plane, but the workflow is different. Knifing is an interactive tool that lets you slice polygons by drawing a line in a 3D view. There are multiple new polygon reduction tools in 4.0. The polygon reduction tool can work in symmetry and preserve the volume and the shape of an object. It is also pretty easy to make quads out of tessellated polys. This is done by interactively tuning the settings until the diagonal edges disappear. This tool is great for models that have been imported. The functionsmooth transition makes edges shrink before they collapse, as the reduction amount is increased and corresponding properties, such as texture UVs and vertex colors, are interpolated. This allows the object to gradually morph when the reduction amount is animated, and avoids sudden popping in the objects shape or textures as edges collapse.

There are new tools that enable direct manipulate subdivision surfaces. This allows you to select points directly on the subdivision surface as with edges and polygons. There are also two new subdivision algorithms. XSI-Doo-Sabin and Linear Subdivision. XSI-Doo-Sabin smooths the surface in a similar fashion as standard Doo-Sabin subdivision, but has several advantages. When the subdivision surface is subdivided, surface attributes such as polygon colors and texture coordinates are properly propagated to the subdivided surface without distortion or error. Creases can be applied to the object in an intuitive fashion and will give results similar to the Catmull-Clark creases. Linear Subdivision will linearly interpolate the vertices. The only case where this will change the shape is for non-planar triangles. The effect is that each polygon becomes a rubber sheet; this will lead to more pleasant behavior as a polygon is deformed. For example: consider twisting a cube. With linear subdivision, the sides of the cube will deform nicely as the cube is twisted. Even if the polygon is planar, this algorithm will affect the texture coordinates distortion created by the triangulation is reduced, since each polygon is broken up into smaller pieces. The new function Extract Polygons (Delete) allows you to extract from a mesh, make a copy of selected polygons and create a new object with them. Extract Polygons (keep) creates a new object but leaves the selected polygons on the original object. If you want to detach the polygons but keep them in the same mesh, the Disconnect Component tool should be used instead. If you want to remove polygons from the original mesh, then Model> Create>Mesh>Extract from Polygons should be used.

The material and texture explorer offers the user a view that displays all of the materials, textures and shaders used by the objects in a scene.


3. Animation

There is a new type of constraint called slider. The slider constraint connects two objects (active or passive) and constrains them so that they move relative to each other along a particular line. Imagine that each object has a small hole drilled through it and is mounted on a frictionless rod, like a bead on a needle. The built in rigs have improved a lot. You can now move the toe and the entire foot will move with it as well. You additionally get components that you can simply add to your rigs, such as fingers, hands and tails. There are also more options that enable skin sliding, better shadow rigs and ghosting, which is very valuable for accurate animation. The new concept, known as timeline-based editing, allows XSI to dock several animation editors together in such a way that they will share the same master timeline, and thus be completely visually synchronized together. This makes it a lot easier to work with multiple editors on animation data, especially for synchronization work.

In addition to the normal ghosting, XSI has IK/FK ghosting as well. You can ghost the display of both the FK and IK solution of a chain, in addition to the blended configuration. It is now possible to convert euler rotation fcurves into quaternion fcurves (both back and forth). This allows editing rotation animation using the quaternion fcurves, in the fcv editor or dopesheet. In the fcurve editor there is a new Quaternion Keys toolbar. This toolbar is used to tweak the tension, continuity, bias and spin parameters at keyframes. XSI now has the ability to display an audio waveform in the background of the function curve editor. This is useful for synchronization of animation with audio and makes lip synching a lot easier. Action sources now have a storage option with a filename as well. This now allows actions to be saved externally, and shared between scenes. The animation mixer has some new powerful cycling tools for building all kinds of cycles out of straightforward animation or MoCap.

Authors Aaron Sims and Michael Isner concentrate on mastering character creation in this new instructional book.


4. Compositing and Paint tools

Vector and raster paint is one of the best features for users of XSIs built in compositor. It is a resolution independent, multi-layer, 16-bit, XSI-scriptable raster and vector paint module based on proven technology from Eddie Media Illusion. With the new tools you will not only be able to animate paint strokes or shapes (to erase wires, make spot corrections, frame-by-frame correction and clone/merge on video/image sequences), but you will also be able to track objects in the source footage and share that information with your composite or objects in your scene. The compositor has had a big overhaul. Much has gone into making it work faster and use ram more efficiently. It does heavy temporal caching of file inputs. If there is plenty of ram available to the compositor, it is possible that files being composited from disk are only accessed once. The new 2D tracking tool in the compositor allows 2 or 4 point tracking for stabilization or corner pinning. And a FX Tree SDK provides support for UFO plug-ins. UFO stands for User Function Objects. This API allows writing plug-ins for the FxTree and offers full access to the internal implementation of image plug-ins, with services for parameter definition and validation and access, region calculation, multithreaded processing and implementing viewer interactive tools. Another cool feature is the support for Avids digital nonlinear accelerator Mojo. It delivers the power of true realtime effects, realtime D1 input and output.

5. Simulation

Working with the new Rigid-Body Dynamics (RBDs) is simple and straightforward. To create rigid body dynamics, you make objects in the scene into rigid body objects. Then you add forces to create movement (wind, gravity, force, motors, impulse, etc.). The dynamics operator then calculates how rigid bodies move according to forces and to the collisions they have with other rigid body objects. It even works with subdivision surfaces. You can set constraints between rigid body objects to limit a rigid body object to a specific type of movement. Hinge constraints make connected rigid bodies move around an axis that acts as a hinge joint; that is, it provides only one degree of freedom in rotation. Rigid-body objects can be either active or passive. Active objects are simulated by the RBD solver. Passive objects are not simulated, but can be keyframe-animated and also act as collision objects for active bodies. You can manipulate passive bodies during a simulation, providing a way to interact with a simulation environment

Particle goals have been added to 4.0. Goals allow a simulated particle cloud to be attracted by one more or more objects. The goal object can be a polygon mesh, nurbs surface, lattice, particle cloud, nurbs curve or any other object. Each particle is assigned a feature of the goal object to be attracted to.

Using the new Hair Geo shader, you can set the diffuse/ambient/specular color shading and transparency for hair that uses only the geometry render type. This offers better control (via gradient) over shading. You can also add incandescence (glow) for the inner and outer hair edges.

The enveloped character.

The enveloped character.

6. Scripting

XSI already supports VBScript, JavaScript, PerlScript and Python on the windows platform. But users that needed Python on Linux were stuck. Softimage hired Mark Hammond, the ActivePython creator, to port Active Python to Linux. There is a relational view that allows for two script editors to sit side by side. It is called Script Editor Dual Pane.It is great when you need to compare scripts, as it shows two script editors side by side, with one log window below. Finally, the user now gets notified when a script file that is being edited, changes on disk. A prompt is displayed asking user if they want to reload script. This allows user to use an external script editor and keep the script file in synch.

7. Rendering

This new version 3.3 of mental ray provides some much needed improvements. One of the most impressive is called rapid motion blur. Over time, mental ray motion blur has gotten marginally faster. However, with this release it jumps far, far ahead of where it was before. Also notable is the inclusion of detailed shadow maps, speeding your production up in much the same way that RenderMans deep shadow maps do. Anyone that does a lot of final gathering work will welcome the inclusion of final gathering preview. This allows for renders to quickly show an approximation of the scene before it shows the final version. With the new metashaders system, XSI shaders can now be written to work with multiple renderers, and the new XGS display will even allow third-party renderers to have dedicated interactive preview windows directly in XSI. You could set up a rendertree for mental ray and use that same tree to render via NVIDIAs CG shading language. The BSP maximum memory optionsets the maximum amount of memory to use for building BSP trees (regular and shadow). This can help if a scene is using extraordinary amount of memory for BSP trees while rendering. There have been some enhancements to toon shadersuch as added switches that allow ink to be drawn in output frame buffers (normal, depth, motion, tag). Toon now integrates a fisheye effect with toon lens.

Scaling the icon for the global SRT.

Scaling the icon for the global SRT.

There is a new hemispherical (Fisheye) Lens Shader. This shader simulates a hemispherical (fisheye) lens capable of rendering a 180-degree field of view with characteristic hemispherical distortion typical of real-world fisheye lenses. There is a new improved workflow in the render tree for inserting and using conversion shaders within property pages. (invert, color to scalar, etc.) The workflow has been modified to make inserting such conversion node easier, and also to make it more direct to navigate to the other shaders without having to bother with the conversion shaders on the way.

There is a new concept called texture layers that is used to simplify the blending of images/shaders/shade trees. It uses compositing techniques to provide new and easy control over creating and editing texture layers. The XSI Graphic Sequencer gives the user the ability to perform display callbacks. These are callbacks that can be called at different places in the display pipeline. They are useful for things like custom displays such as HUDs and scene level effects (such as fog, background image/colors). XSI 4.0 also adds a new DirectX9 display mode for displaying DirectX 9.0 realtime shaders. There is a new renderer option in the rendering options. You can now choose between mental ray, CG, OpenGL and many other options.

Syflex partners with Softimage to provide a free license of cloth simulation to every one of its users.


Other Cool Stuff

  • Users of XSI Advanced will get a 4 CPU mental ray v.3.3 rendering license. 1 advanced and 1 batch render, where each license can unlock 2 CPUs for rendering on dual processors.
  • More robustness, performance and functionality because of the revamp of the override architecture
  • Visible in render in the light property page makes the area light visible in the render output based on its color which is useful for making lights show up in reflections.
  • New materials library loads a lot of new sample materials and is also a good system for storing current materials making it easier to re-use and deploy across distributed teams.
  • The material and texture explorer is a new two-pane view that displays all of the materials, textures and shaders used by the objects in your scene.
  • The leader in cloth simulation, Syflex, has partnered with Softimage to provide a free license of cloth to every one of its users
  • You can now do smooth scrubbing, in a variety of modes (direct synch-to-frame, realtime playback, vari-speed or user-defined rate).
  • Autokey has a new option to determine when autokey will result in keys being created/edited.
  • When the phoneme key display mode is enabled, keys that belong to weight fcurves (notably shapekey weights) will be displayed in an alternate way, allowing you to see which key has an effect where on the dopesheet over time.
  • The smoothing deform operator can be used to control the bulge effect at the joint.
  • The construction modes allow you to adjust anything on your character at any time.
  • LOD controls allow you to generate several versions of an object at different levels of detail.
  • The Smooth operator is a general purpose deformation that removes spikiness and other high-frequency detail.
  • Welding and Un-welding points have been made a lot more easier. There is also an option to detach the polygons as a single unit or individual polys.
  • The feature called dicing works exactly like Effect>Subdivision from Softimage3D.
  • The preferences panel has been completely redesigned and is much more stable
  • 4.0 comes with a new application, called XSICabs. It provides Softimage an easy way to resolve bugs in XSI.
  • You can lock any node or possible to tag parameters.
  • The plug-in manager takes care of loading self-installed plug-ins at startup.
  • Avid 3D is geared toward video editors. It is a drag and drop, text and logo application based on XSI and mental ray rendering.
The Softimage Production Series DVD set gives new users a quick and painless introduction to the software.


II. XSI Learning Tools

Since the dramatic price drops of professional 3D software, getting access to it has become less problematic than two years ago. Although XSI is no software for the 3D novice, it can give you an entry point on how professional 3D is done. Learning materials such as the Production Series DVDs or the Experience XSI 4 book by Aaron Sims and Michael Isner are just the start of a new series of books and DVDs that launched in 2004.

The Softimage Production Series DVD set covers all five major topics of working with XSI to give the user a quick and painless start: Animating in XSI, Modeling & Texturing in XSI, Simulation in XSI, Rendering in XSI, Rendering Concepts for XSI and Principles of XSI. The latter DVD is not part of the set of five and is intended for the new user. The DVD is sold separately and includes 178 tutorial videos divided into categories, such as interface, model, animate, render and simulate, composite and Maya transition. It is possible to buy the DVDs for $49.95 each, but I would recommend the complete bundle (available for $199.95 at the Softimage Online Store:, especially for XSI Newbies who want to learn how to use the software efficiently from start to end of production.

Many artists favor a combination of the DVDs with the Experience XSI 4 The Official Softimage XSI 4 Guide to Character Creation.

Character Creation is a very hot topic in 3D, but creating complex characters is one of the most difficult skills you can obtain. Many of the recent top grossing Hollywood movies such as Spider-Man 2, The Lord of the Rings trilogy and Terminator 3 all feature highly realistic 3D characters. Softimage XSI is one of those professional tools that helped to make the Terminatrix become real, so it stands to reason that one of the authors, Sims, would be working at SW Digital, the design division at Stan Winston Studio. Together with Isner, character animation lead for Softimage, Thompson Course found two very capable experts to write one of the rare books to help master character creation in XSI. Experience XSI 4 is an easy to follow and comprehensive book, which doesnt waste a lot of time explaining every feature in detail. Rather, it focuses on the specific needs to get on with the scene with enough useful examples for even a Softimage-Newbie. The authors show how to design, model, texture, light, render and composite your character. The book also gives examples on making crowds and character logic with Softimage Behavior. Even the seemingly difficult topic of scripting appears to be easy going and gives the reader a good first impression of how to control space with a little bit of math. The book appeals to both the intermediate users as well as experienced artists looking for a comprehensive guide to find their way around in XSI 4.0 Additional files such as a texture collection, sample background images, a hot key list and examples of 3D character models that are textured, rigged and weighted can be found on the publishers Website

Ed Harriss is a 3D artist/technical director, working at Alternate Route Studios in North Carolina. He is a Softimage expert and very well known in the community for his Softimage Learning Tools and his book How to Get a Job in CG. He also writes for several online and print magazines and is forum moderator on XSI