Earlier this year I was beta testing Zbrush 2018 for Pixologic. These are some screen captures that I did during the process of concepting/modeling a mech. You can see me use the new feature "project primitive" for instance. Thanks a bunch to Pixologic for including me in the beta testing and giving us all these new features!
All renders were done in the realtime viewport "Eevee" in Blender 2.8, which is under development.
Blender is a free 3d application that can be used for any purpose. Please note that the Eevee viewport is still very much in production and the build is unstable. You can download the stable release of Blender here https://www.blender.org/download/ And you can try the Eevee viewport if you download an unstable build of Blender 2.8. https://builder.blender.org/download/