The decision whether to purchase Autodesk VIZ or opt instead for its big brother max is still an area where confusion reigns supreme. It's still a common misconception that 3D Studio VIZ is simply a "cut down" version of 3D Studio max. Whilst it is true to say that VIZ does lack some of the higher-end features of max, what is not so readily understood is that it also boasts some rather nifty features of its own which you definitely won't find in max.

So, what exactly is VIZ and how does it relate to max? VIZ is essentially an enhanced subset of max. In other words it is based on the same code with some functionality removed and new design specific functionality added. As max is designed as a tool for professional animators and games designers, it contains many advanced modelling and animation features not found in VIZ. These range from sophisticated simulation of real world dynamics to the bizarre morphing and particle effects seen in many feature films.

So, if it's dancing grasshoppers or exploding spaceships you want, then max is definitely the product for you. For the rest of us, VIZ not only provides all of the visualisation tools we need but also streamlines them with the design products that we already use. Interestingly though, Autodesk estimates that around 35% of 3D Studio max sales still find their way into design visualisation despite VIZ being around half the price. Many of these will more than likely be used in situations where a number of VIZ workstations are already in use. max might be a very useful addition to the designer's toolkit for any of the following reasons:

• Where there is a requirement to animate people in scenes, the Character Studio extension can be used but only with max.
• The particle system in max can be used to show heat, water and fluid movement in an animation.
• The dynamics systems in max can be used to produce realistic animation of real world objects.
• For situations where mechanisms and event-driven animation is needed, the animation system in max (including sub-object animation) would be invaluable.
• There are certain potentially useful plugins which only work with max, the simulation of cloth for example.
• The video post capabilities of max of compositing and editing sequences are required, although much of this could be done using VIZ in conjunction with a dedicated video-editing product such as Adobe Premiere.

max is designed to accommodate professional animators and games designers. Therefore it contains many advanced animation features not found in VIZ:

• Video Post - the ability to composit, apply special effects and complete basic editing tasks for finishing a sequence before output as an AVI, web format or to video.
• Sub-Object Animation - the ability to control individual parts of an assembly or object, or even the parameters for an object such as length, height, number of segments, or twisting of an object over time.
• Dynamics - the ability to have objects bounce, collide, fall in a realistic manner with controls such as gravity, surface finish, distortion etc.
• Motion Capture - the ability to drive in real-time, the animation of an object by any input device, from the mouse to a lever or complete motion capture body suit.
• Inverse Kinematics and Skinning - the ability to animate and deform an object with an internal 'bone' structure and have the object's 'skin' follow correctly with bulges and tucks similar to muscles.
• Spacewarps - the ability to deform and animate an object by a shape modifier placed within the scene, flags waving, cloth rippling etc.
• Particle systems - the ability to use small particles of various shapes or substitute modelled objects, whose behaviour is driven by physical properties such as wind, gravity, collision, size and spray.
• Lens Effects - specific rendering effects that add flares, lighting effects, depth of field, etc., to a rendered image or sequence. Some of these are now available in VIZ by using the render effects.
• Morph objects - the ability to transform the one object into another over an animation, such as showing the new version of a product 'growing' from the old version.
• Atmospheric Apparatus - controllers such as wind and gravity, placed into a scene to control particles and dynamics.

What can you do with Autodesk VIZ that you can't do with 3ds max?

Aimed purely at design visualisation, VIZ has a number of features which are specific to the CAD user:

• File Linking - You can have dynamic live links directly to AutoCAD model files rather than having to import them. This means that as changes are made to the master DWG file, you'll see those changes update within VIZ. Consequently, there's no need to have several versions of your designs floating around.
  
• Layer Support - VIZ incorporates a new layering system based on layers found in AutoCAD 2000 based applications. Design with layers in VIZ just as you would in your design tool or when you link to a DWG file, you can transfer your entire layer structure into VIZ and continue working just as if you were still in your design tool.
  
• AutoCAD-style interface - Switching between your design tool and VIZ is much easier now, due to the fact that the interfaces are very similar. Furthermore, thanks to the custom user interface technology from max, tailoring the interface to suit your needs is very straightforward using simple drag-and-drop operations.
  
• Hidden Line Renderer - The new hidden line renderer allows you to render any viewport as a hidden line representation. It's both fast and easy to use. It also will save the resultant rendering to a DWG or EPS file which you can later use in your design tools or presentations.
  
• Asset Browser and VIZ Online - Getting to your vendors through the web can be done quickly through the new Asset Browser. Based on Internet Explorer, you can browse both local and on-line content which can be dragged right into a viewport for use in your design. Drop 2D images such as aerial photographs or 3D data such as mechanical components either with the Asset Browser as a floating window or dockable viewport.
  
• Modelling Context - Sculpt complex forms using simple shapes and primitives with the modelling context mode. Operations such as interactive emboss or reveals are accessible with a single button click.
  
• Extended AEC objects (walls, foliage, railings, terrain)
  
• Design Visualisation Specific Materials - VIZ R3 comes with a complete set of industry-specific materials that you can simply drag and drop into your designs. There's also a new procedural brick object that creates realistic brick and tiled patterns automatically.

Remember that if you do use both products there will be some issues that you need to be aware of when sharing or migrating models. These mainly arise from the use of VIZ specific objects such as walls, terrain and foliage as max does not support these. If you are, for example, planning to take VIZ models into max for further animation and video post work, do make sure that all VIZ specific objects have been collapsed to meshes BEFORE the model is opened up in max. This also applies to linked AutoCAD DWG files, which must first be bound and then reduced to meshes. Remember that once objects are collapsed to meshes all of their intelligence is lost, so it is important not to overwrite your original model file!