The plugin that offers a professional, for a free and open-source 3D computer graphics software toolset used for creating animated films, visual effects, art, 3D printed models, interactive 3D applications and video games,   3D modeling of what?
ManuelbastioniLAB ManuelbastioniLAB is a free and open source plug-in for Blender for the parametric 3D modeling of photorealistic humanoid characters.
CityEngine Esri CityEngine is a three-dimensional (3D) modeling software application developed by Esri R&D Center Zurich (formerly Procedural Inc.) and is specialized in the generation of 3D urban environments. With the procedural modeling approach, CityEngine supports the creation of detailed large-scale 3D city models. CityEngine works with architectural object placement and arrangement in the same manner that VUE manages terrain, ecosystems and atmosphere mapping.