BodyPaint 3D is a tool designed to ease that bane of all 3D artists’ lives: how to map textures onto an object without distortion. To this end, BodyPaint makes extensive use of UV mapping to allow this to be carried out easily and efficiently.
UV mapping works by ‘pinning’ a texture bitmap to a model’s mesh – you can think of the map as being tacked on at the vertices, so that it conforms at every point, and if the mesh moves, the map moves with it. Result: no texture slippage.
In order to do this, the mesh must be unfolded so that can link to what is essentially a flat image (your bitmap). This also means that the markings on your bitmap may appear stretched and distorted in relation to their final appearance on your model. However, add in BodyPaint 3D to continually calculate the mapping between the flat bitmap and the folded mesh, and you can add paint, colour, bump, transparency, environment, specularity, and such like onto your model, all in real-time.
The interface consists of two large windows, one showing a perspective view of your model, the other the flat bitmap that you’re working on. It shares many similarities with Cinema 4D XL itself, and there’s an option to install BodyPaint within XL if you wish.
This synergy with XL is one of its greatest strengths, but also a weakness in that it also shares XL’s fractured approach to textures – their attributes are accessed from different parts of the interface: channel attributes both from the Materials manager and from the Layers manager, mapping type and offsets from the Object Manager.
After first creating a material and assigning it and a mapping type (usually UV) to your object, you then choose a channel type from the Layers manager. This assigns the first layer, and this is what you’ll be painting into, usually colour first. After moving the new layer bitmap into the Texture view, you can start painting. Once you start, the brushstrokes appear magically on your mesh – whether you’re painting into the Texture View window or directly onto the mesh in perspective.
For painting, you use brushes, and BodyPaint 3D comes supplied with a fair few pre-set ones to get you going, including natural-media such as chalk. Each one can be used as the starting point for designing others, which can be saved in folder sets.
BodyPaint 3D feels a lot like Adobe Photoshop, with filter sets, layers, layer masks and blending modes. The other major similarity is that it ideally needs a graphics tablet to get the most out of it. A big difference is that with BodyPaint you can have multiple layers per channel. As far as layers go, one thing that struck us as odd is that although you can have multiple layers, each containing a different image in, say, the Bump channel, there’s only one master slider to vary the Bump strength of each layer, and that resides in the Material’s swatch in the Material Browser. It would be nice to have everything relating to textures available from the same place in the interface.
Despite these odd quirks, BodyPaint 3D works well, especially in the speed department. On a Power Mac G4 450MHz and a Pentium III 733MHz it fairly flew. Of course, texture size and the number of layers will cause slowdowns. In short, BodyPaint 3D is a tool that’s well worth getting into.