Sculptris is a useful (and free!) modelling application that’s similar in many ways to Zbrush. In fact it’s so similar that the makers of Zbrush, Pixologic, persuaded the developer to join their team.
It’s a 3D sculpting app that allows you to work with a piece of virtual clay, shaping it with a variety of tools.
It’s an excellent tool for adding organic details like cloth wrinkles or shaping complex curves and surfaces. Unlike Zbrush where you subdivide the entire mesh for higher detail, Sculptris dynamically adds detail to the mesh where you paint with the brushes. This can lead to some very dense meshes in places but it also has some very nice tools for reducing this complexity down again.
It’s more than just a sculpting tool, though. If you import a Wavefront OBJ file that already has a UV map then it will offer you the option to go “straight to paint”. In this mode you can paint colour and patterns directly onto the mesh and then save out a texture map image.
The painting tools are basic but it can be a useful tool for laying out how lines or textures will cross UV boundaries or for just doing a little touching up around the seams where things don’t quite match up.
Unfortunately development of Sculptris seems to have stalled and there hasn’t been a new version for a while. The current version does have a few problems – mostly related to sudden crashes, so save your work early and often.
You can download Sculptris from its site: http://www.pixologic.com/sculptris/