Issue: Volume: 26 Issue: 1 (Jan 2003)

Modeling and Painting


Pixologic's 2.5D sculpting and painting tool

By Doug King

Pixologic promotes ZBrush as a 2.5D digital art creation program for the artist, game developer, graphic designer, hobbyist, and professional artist. I have to admit I was skeptical about how much it could accomplish, but I was also curious to try out the latest version, 1.5.1, as I'd been impressed by some of the images I'd seen created with ZBrush.

Working in ZBrush is like sculpting or painting with wet oil paint. Once you've created a 3D object, you can paint new contours and shape the object using the Edit mode. All this is completed in real time, which is one of the most important features of ZBrush. Like other paint packages, ZBrush uses layers, so you can work on different parts of your painting without affecting the rest.

One of the two coolest new features is TextureMaster, a powerful tool for painting directly on your 3D object, and thus avoiding seams and stretching. What sets ZBrush apart from similar programs is that TextureMaster gives you the ability to paint with any 2D or 3D tool within the program, and create incredible 3D shaded objects, which can then be baked into the texture. Materials can be applied to the textures for different looks such as shininess and bump.

TextureMaster can be used to paint 3D textures on models you build in other programs and import in DXF or OBJ format. You can paint in 3D wrapped or unwrapped mode. The finished texture can then be exported back to your native program.

The second powerful new tool that makes ZBrush special is ZSpheres. These tiny spheres can be used to create complex 3D models. In some ways, using them is similar to modeling with metaballs or polygons. But instead of extruding faces on a polygon, you create a preview sphere and then use the X-Symmetry edit feature to add spheres to the preview. The program automatically adds "tween" spheres to fill in the model. With your ZSpheres created you can modify individual spheres or entire chains using the move, scale, and rotate modifiers.

After you have completed construction of your basic model, you create a skin, essentially a mesh that follows the contours of the ZSpheres. There are two skinning methods within which you can control polygon resolution. There is Unified skinning for higher polygon count and softer shape, or Adaptive skinning, which creates lower polygon models that are ideal for game applications. Meshes created using ZSpheres automatically have UV coordinates assigned. At any time during modeling with ZSpheres, you can press the Preview button to see the results of your final mesh.

Other additions to Version 1.5.1 include an updated interface that offers a streamlined workflow with instant access to almost every major palette. One of the new tools I liked is the Make3D button in the Alpha palette. With it, you can essentially turn anything you paint into a 3D object. This is a very cool feature that can be used when you want to create multiple copies of something you have painted. Once you have completed the Alpha Skinning, in which you control the resolution and depth, your object is automatically placed in the Tool palette for later use. This new 3D object can then be modified like any other object.

Lighting in ZBrush has been enhanced. Now you can save and load lighting setups. Also, new shadow modifiers take advantage of ZBrush's improved rendering engine. New global illumination principles have also been added to the rendering engine, which should give you the ability to create more realistic images.

One area I found lacking was reference material. There are dozens of hotkey shortcuts but no documentation to tell you what they are. Pixologic has incorporated ZScripts that run inside the interface and teach you how to use ZBrush. While innovative, one drawback is that you cannot pause these scripts and interact with them. If you miss a point or want something repeated you must start from the beginning.

After having explored the program firsthand I must admit that I was surprised and impressed with its depth. Although it will not replace my main 3D modeling packages (and is not supposed to) it offers enough tools and features to be included in a well-rounded studio. I also recommend it for concept artists who wish to give their "sketches" a more polished look. And I can see this being used as a quick previsualization tool in pre-production.

Douglas King is a writer and animator based in Dallas, Texas. He is currently developing animated projects for his company, Day III Productions.






ZBrush's new ZSpheres tool allows users to create more complex models. Image courtesy Ken Brilliant and Pixologic.




Stats, ZBrush 1.5.1
Pixologic www.pixologic.com
stats Price:$399
Minimum System Requirements: Windows 95/98/ME/.NT/2000/XP and 200MHz PIII. Mac OS 8.5 and G3 or G4 Mac processor; 128MB of RAM




Modeling

Muscles for 3ds max from cgCharacter

By Doug King

As any animator can tell you, one of the biggest challenges in creating realistic character animation with only skin and bones is that the skin does not deform properly. When Jurassic Park premiered, a highlight of the movie was the incredible skin deformation of the dinosaurs.

In fact, it is the vast network of muscles attached to the skeleton that deforms the skin. With that in mind, cgCharacter developed a program called Absolute Character Tools (ACT), now in Version 1.5, that serves as a musculature system for Discreet's 3ds max 4 and later versions. A Maya port is also being developed. What ACT does, basically, is put meat on your model's bones. The plug-in is used atop 3ds max's Skin, character Studio's Physique, and the 3ds max plug-in Bones Pro.

However, don't expect ACT to simplify the process of building a complete muscle system for your character. While you don't necessarily have to build every muscle group in the human body, and you don't have to be a biology major, the programmers of ACT expect that you have a strong background in character animation.

ACT comes with two new classes of 3D objects for 3ds max: cgMuscles and cgTubes. The cgMuscles are parametric 3D objects. As you link them to objects, they will automatically deform as the "parent" objects move. Here lies the true benefit of the program—the automatic deformation of a muscle immediately after it is created. The cgMuscle is designed to deform to keep the ends in the same positions relative to their attachment object's coordinate space.

What this means is that after modeling your character, adding a Bone skeleton ,and setting up the rigging, you can then add a layer of muscle using ACT, and you should have a completely deformable, animatable character. Some tweaking of the muscle's parameters will be required, and all of these are animatable as well.

You begin the process of creating a muscle in ACT by choosing the cgMuscle object from a drop-down panel, then defining the proximal (start) and distal (end) connections for the muscle. In fact, creating muscles in ACT is entirely too simple—it's just like drawing a line. It is after drawing the muscles around your character that both the work, and the power, of ACT really begin.

Within the program's Modifier panel you will find a number of options, including Muscle Structure, Hierarchy, Textures, and Deformations. Within the Deformation option is a drop-down panel from which you select the deformation engine you wish to run on your muscles. The deformation engines define how muscles will behave when you move the skeleton structure they are attached to. These engines are plug-ins to ACT, so there may be future updates, and new engines available from the developers.

Once selected, an engine presents you with numerous options. For instance, within the Blend engine, you have control over Bulge, Static Forces, Collision, and Dynamics. Within each of these are sliders for controlling the fine details of the muscle. It will take most users a good deal of experimentation to fully grasp all that ACT allows you to do and to obtain the exact animation you need for your scene.

UV coordinates of cgMuscles are automatically set procedurally. You may override these with a UVW mapping modifier. It is important to set up the texturing, since it defines the transition from the tendon at both ends to the muscle in the middle. This affects how some of the deformation engines will work with the muscle. Again, experimentation is required, as the documentation doesn't offer much help.

The program also adds new modifiers designed to work with the cgMuscles. The most important is the cgDeformation modifier, which is applied to your character mesh. Within the cgMeshDeformation modifier panel is the cgMeshDeformation Pipeline. This plug-in implements a set of deformers for muscle and bones under the skin and implements a special UV mesh deformation for skin stretching and sliding without changing the shape of the skin.

All in all, ACT is interesting to work with but not especially user friendly. It would be nice to have more reference materials. ACT is not for the faint of heart or for those starting out as animators. You had better have a good understanding of character rigging and animation before jumping into this program. If you do, you should be happy with the results.

Douglas King is a writer and animator based in Dallas, Texas. He is currently developing animated projects for his company, Day III Productions.






ACT 1.5, a musculature system for Discreet's 3ds max, helps animators fill the gap between skin and bones. Image courtesy cgCharacter.




Stats Absolute Character Tools 1.5
cgCharacter www.cgcharacter.com
Price: $995
Minimum System Requirements: Discreet's 3ds max 4; 64MB of RAM
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