K-3D is a great tool for artists to build 3D objects and animations. Users will find the K-3D main user interface very easy to understand that will inspire you to build creative things. It can be used as alternative to 3D Studio Max.
The K-3D software is available in the official Ubuntu repository, you can install it with this command from the terminal under Ubuntu 11.10/11.04:
sudo apt-get install k3d
Screenshot for K-3D under Ubuntu Oneiric:
Here is a tutorial for creating a 3D Mug using K-3D:
To learn how to use K-3D or see its full features, you can check this link.