Introduction
Softimage XSI has an amazing heritage. Softimage has been a staple in high-end computer graphics (CG) studios since the early '90s, giving the software a level of experience and breadth that few other 3d packages have. For many years, Softimage has been comfortable to lead the high-end animation market with few other competitors. Among all the 3d software offerings it was quite expensive, but yielded amazing results that were worth the high cost. Because of the high price tag, Softimage was mainly used for film work.

Softimage, the company, was bought and sold several times over the last 10 years, even being part of Microsoft for awhile. Today, it is owned by Avid, who produces broadcast quality video editing tools and solutions. Avid sees Softimage as a critical piece of the video editing pipeline that they support and has been putting a lot of resources and focus into Softimage.

Recently, Avid stunned the CG industry by slashing the price on their base XSI package. For the first time ever, state-of-the-art film effects were available at a price that a hobbyist could afford. The sales of Softimage XSI have skyrocketed since this announcement and the number of users continues to grow.

The increasing quality of game content coupled with a lower price point has made Softimage a viable package for the game industry. Several game studios have adopted Softimage including Vault and Epic. Softimage has responded by adding more and more character and game specific features to their newer versions. Softimage offers a free version, which allows "modders" to create custom content for games such as Half Life 2 and Unreal Tournament 3.

Softimage XSI is available in three different flavors. Foundation is a low-cost offering that includes a majority of the available features. Essentials includes all the tools needed to do quality production work and Advanced adds in a behavioral animation, a cloth solver, dynamic hair and fur and more rendering licenses. Softimage XSI is available for Windows and Linux-based systems. There are also 64-bit versions of XSI available that offer amazing speed and power.

The Softimage XSI Interface
The Softimage XSI interface has controls surrounding every side of the central viewports (see Figure 1). The right panel includes controls for selecting and transforming and the left panel are dynamic buttons that can switch between different button sets—Model, Animate, Render, Simulate, and Hair. Each of the different menu sets are color coded, which is a nice visual clue for insuring that you're using the correct menu set. The basic animation controls are located along the bottom edge of the interface. If you don't like the default interface setup, it is completely customizable.

The Softimage XSI interface controls are wrapped about the central viewports (click for a full-size image).

Along the bottom edge of the interface are three fields marked L, M, and R. These fields show the available commands for the left, middle and right mouse buttons and are helpful if you get lost. Softimage makes good use of context-sensitive pop-up menus, which display relevant commands based on where you click.

Another helpful interface element is the Explorer, which is a window that displays a hierarchical list of the scene objects. From the Explorer, you can quickly get access to commands such as clone, group, lock and view properties. This is convenient as the scene becomes more and more complex. The Explorer window also makes it easy to parent objects. The Explorer can also be displayed within a view window.

Navigating the view windows takes some getting used to. You can hold the Z key to zoom and pan, the O key to orbit around the scene selection, and the P key to pan. The easiest navigation method is the S key, which lets you pan, zoom and rotate using the different mouse buttons. It's great to have multiple options, but the easiest method is to have only one option that works great. Softimage includes keyboard mappings that allow it to be controlled using the standard 3ds Max keystrokes. This is a nice feature and makes the interface feel right-at-home for other users of other packages.

I found the interface to be painful to use at lower resolutions, but at higher resolutions, more controls become available making the interface comfortable. Be warned that there are an overload of features and you'll need to some time to learn and become familiar with all the different controls.

Modeling
The modeling features included in XSI let you work with curves, primitives, polygons, subdivision surfaces, and NURBS surfaces. The Model menu also includes default primitives for creating male and female skeletons, bodies and faces, bipeds and quadrupeds, each with its own set of properties. For example, the FaceMaker panel includes properties for controlling the size, roundness, length, and width of the head, as well as, specialized properties for the forehead, eyes, nose, mouth and ears (Figure 2). These properties make it easy to quickly create a unique head that is parametrically sound and smooth.

The Facemaker primitive provides a good starting point for rapidly creating character models.

There are also many different ways to deform existing models including standard deformation operators like Bend, Bulge, Taper and Twist. You can also deform objects using a Lattice. XSI also includes many unique and interesting methods for altering objects such as bridge, booleans, symmetry and randomize features. Individual components can be selected and transformed using the Tweak Component tool. You can also deform surfaces using the Push Paint tool, which lets you deform object using a brush. The Proportional Modeling mode lets you move the components surrounding the current selection to a lesser extent causing a gradual deformation.

Every modeling command is kept in a operator stack that provides a living history for the object. The stack also lets you revisit operations and change its properties, delete operations and re-order them as needed. There is also an Immediate Mode that lets you model without adding to the stack or you can collapse the stack to make the scene files smaller and quicker.

There is also a polygon reduction tool that is a good example of the game-specific features that have been added to the software. This feature can reduce the number of polygons in a model while maintaining the shape of the object. It is ideal for quickly creating LOD models.

To keep track of all the various resources for a project, Softimage is tightly integrated with the AlienBrain content management product. This product allows production teams to work together on common assets without overwriting each other's work.

Animation
For animating, Softimage XSI includes the usual fare for creating keyframe animation and animating along a path, but it also includes many advanced tools including a function curve editor, a dope sheet, an expression editor and an Animation Mixer that lets you quickly overlay and blend different animation clips.

Animation sequences can be copied between objects. You can also select to optimize an animation for playback by reducing its keys. There is also a Shape Modeling Construction Mode where you can build morph targets for creating subtle animation changes such as lip synching.

Characters
Softimage XSI includes some robust character animation tools that make it easy to quickly rig and animate characters. One of these tools is the Synoptic View, which displays a labeled view of the character and includes controls for matching feature definitions using symmetry.

There are also several default bipeds and quadpeds for quickly rigging humans and animals. Softimage even includes a feature that makes the character follow a defined path of footsteps similar to the Biped feature in 3ds Max. It also provides features for quickly rigging and skinning characters that are much faster and cleaner than the similar features in Max or Maya.

One place where Softimage shines is in the facial animation arena with their new Face Robot system. This system lets you place points on the face to define the facial structure without expensive motion capture. These points then allow the face to be deformed in a realistic manner. The results are amazing and expressive. Face Robot is a separate product available from Softimage and can be integrated into XSI or into other 3d products.

The Gator tool is an awesome tool for transferring attributes between characters including texture coordinates, skin weights and vertex colors. If you want to borrow the settings for one character's body and apply it to another, then simply click on the Gator tool and select each object in turn and the attributes magically show up on the new character.

The Ultimapper tool is useful for baking all textures and lighting for a character into a single map (figure 3). It can also be used to transfer high-res texture maps onto lower-res counterparts. It includes support for Normal, Albedo, Depth, and Ambient Occlusion maps.

Figure 3: Character models in XSI can be mapped with several different textures.

The Behavior system allows you to take rigged characters and define how they move based on environmental conditions. This is ideal for creating crowd scenes where the character are autonomous. The Behavior system is only available for XSI Advanced.

Rendering
Softimage includes broad support for several different shaders such as the x-ray shader, used to create figure 4. Softimage even includes the ability to work with OpenGL and DirectX real-time shaders.

Figure 4: Shaders such as this x-ray shader can give your objects a unique look when rendered.

The Render Tree lets you have access to a full range of lighting effects including lens flares, glows, ambient occlusion and subsurface scattering. You can also add motion blur to your rendered scenes.

Softimage's core rendering engine is mental ray 3.4. The rendering features in XSI are amazing with complete control over all the various rendering passes. There is also the ability to multi-thread rendering jobs on a computer with multiple processors or render a job over the network with XSI's distributed rendering feature.

Built-in Compositing
In addition to being a powerful modeling, rendering and animation system, Softimage XSI also includes a full-featured compositor and 2D paint system. The compositing interface is called FX Illusion. It includes over 130 compositing and effects operators and 48 different painterly effects that can be applied to a rendered image (figure 5).

Figure 5: The compositor interface includes a wide range of effects and operators that can be applied to a rendered image.

Hair, Cloth and Fluids
Softimage XSI Advanced also includes a Hair feature for adding hair and fur to objects. Hair can also be dynamically altered as part of a simulation. Hair systems include guide hairs that define the general position of the hairs and render hairs that are interpolated between the adjacent guide hairs. A hair system can be styled using the various styling operators, which give you the ability to cut, puff, comb, clump, scale, curl, and frizz hair.

XSI's cloth system is a spring-based model that allows cloth to be animated dynamically using forces such as wind and gravity. By defining the various spring groups, you can make the cloth behave like silk or rigid like leather. Several cloth groups can be stitched together to create a complex cloth system. The cloth presets include carpet, chiffon, leather, nylon, pizza dough, plastic and silk (figure 6).

XSI also includes a fluid simulation system. The Essentials and Advanced versions of Softimage include a fluids solver that can simulate the movement of fluids including waving and splashing.

Figure 6: Cloth drapes naturally over a model and moves with the animated body.

Simulation
Rather that several attached dynamic features added to an animation package, Softimage XSI includes a full-blow simulation engine that includes features for simulating rigid and soft body objects, cloth and particles. Forces, such as gravity, wind, fan, drag, attractor, vortex, turbulence, and eddy, can be added to the scene or made to interact with specific objects. The simulation engine can also detect collisions between the different objects.

There is also a robust set of particles that can be added to a scene including a deep interface of Shader Presets for creating everything from flames and explosions to ice and crystals.

Summary
Overall, Softimage XSI 7 is a full-featured package with all the extras that you could want. The development team is focused on adding in new features specific to the game market. The interface takes some getting used to, but once you get a handle on it, you want be wanting for any features. Some specific features like Gator, Face Robot, and Ultimapper are the best of any package out there.

Since the render engine is based on mental ray 3.4, the final rendered images are gorgeous, as evident in the visuals taken from games like Half Life 2 and Hitman. The character primitives and pre-built rigs make building a character from scratch easy and quick. If you're working on a game requiring dynamic simulations or crowds, then the Advanced version is a must-have.

The most recently released version is Softimage 7. For more information on Softimage XSI, visit the Softimage web site located at www.softimage.com.

Kelly L. Murdock is the president of Logical Paradox Design, a design firm specializing in 3d graphics. He's written extensively on 3d graphics including books on 3ds max, Maya, LightWave and Poser.

by Kelly L. Murdock
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