Sunflow Rendering System is described as 'Sunflow is an open source rendering system for photo-realistic image synthesis. It is written in Java and built around a flexible ray tracing core and an extensible object-oriented design'. There are more than 25 alternatives to Sunflow Rendering System for a variety of platforms, including Windows, Mac, Linux, Autodesk 3ds Max and Sketchup. The best alternative is Adobe Dimension. It's not free, so if you're looking for a free alternative, you could try Cycles Renderer or LuxCoreRender. Other great apps like Sunflow Rendering System are POV-Ray (Free, Open Source), Keyshot (Paid), V-Ray (Paid) and appleseed (Free, Open Source).
NOX Renderer is a rendering software based on unbiased methods. The renderer is available as a standalone Windows executable with a plug-in to link it to 3ds Max. A linking script is also available for Blender users.
Visual Designer is an advanced GPU & CPU photorealistic renderer with a unique set of features to handle all the aspects of your creation. It will save a significant amount of time and let you concentrate on refining your designs & arts aesthetics.
Nebula is a powerful physically based renderer with realtime preview. Two rendering modes are supported: - Pure CPU ray-tracing - Hybrid mode using the GPU General features: - Intuitive user interface with multiple settings(materials, rendering, lights, ...
Maverick Studio is a GPU-accelerated render engine for engineers, designers and artists. Capable of outstanding quality and performance, it packs an impressive list of features at an aggressive price point. Anyone can try it for free, for 30 days.
MiniLight is a minimal global illumination renderer. It is primarily an exercise in simplicity. But that makes it a good base and benchmark (in some sense) for development and experimentation. And it just might be the neatest renderer around (on average, about 650 lines).
fryrender is the physically-based light simulator developed by RandomControl. It is a photo-realistic render engine where all the elements involved in the generation of the final image (materials, lights and cameras) are based on physically accurate models.