Kerkythea is a free rendering program. Unlike Blender 3D, it is purely designed for rendering and it is very good at that.
Kerkythea’s interface is fairly easy to understand. If you want a good renderer but find Blender’s interface too intimidating to understand, Kerkythea Rendering System may be the right tool for you.
Kerkythea comes with libraries of pre-defined materials. You can create and edit your own materials or simply assign the pre-defined materials to your 3D model.
There are also additional material and global setting libraries that do not come imcluded in the basic installation. These additional libraries can be obtain from Kerkythea’s main site.
Rendering-capability wise, Kerkythea is capable of generating images using Global Illumination. It supports functions such as HDRI (High Dynamic Range Imaging) and caustics.
Kerkythea can import 3D models in several formats such as 3DS, OBJ, etc. Both formats are supported by Rhino 3D. Thus Kerkythea makes for a good rendering support for design concepts and models created using Rhino 3D. Below is an example of a Rhino 3D model that was rendered using Kerkythea. As you can see, Kerkythea is capable of generating photo-realistic renderings.
Although. Kerkythea’s interface is quite intuitive and easy to comprehend, in my opinion, it is not easy to get the rendering effects as intended. This is not because the program is not good. On the contrary, it is because Kerkythea have too many options and features. The vast arrays of features can produce many possibilities.
You can get Kerkythea from http://www.kerkythea.net/joomla/