Really cool you chose to do an image processing demo with the "color grading" example. That is such a natural fit for visual programming. I could see Luna fitting into a video post-production or digital asset creation pipeline for games. The combination of a visual interface and functional logic could be used to create mind-blowing custom procedural solutions! Have you given any thought as to what media libraries you might use for the final stage rendering of audio, video, bitmaps, 3d scenes, etc. Because I think it's possible it may be entirely done in HTML5 / JS...
The thing there is that is already how image processing and compositing has been done for 30 years. Check out Nuke, Digital Fusion (which is free), Shake, Flame, etc.
@CyberDildonics, I think that @indescions_2017 was referring to pipelines suitable to be run inside game engines, working at "runtime", not batch-processing data upfront. You cannot utilize any of the software you mentioned to do it. You can use Houdini engine, but it's image processing capabilities are super limited currently and even if they improve, you are limited to thinking in the context of SOPs, DOPs, CHOPs etc, without being able to extend it with custom datatypes and procedures.
TouchDesigner (https://www.derivative.ca/) or vvvv (https://vvvv.org/) are more comparable, since these systems DO work in realtime environments. But yeah, you still have to think in the context of SOPs, TOPs, CHOPs...
You cannot embed touchdesigner in a game engine (at last with ease). VVVV does not comes with abstraction over DOPs SOPs etc, but both are still very limited regarding what datatypes they can process.
Are you asking about Luna? :) Sure! Luna comes currently with its VM but we are also working on a backend allowing to compile it to machine code, so every graph you write can be also used as a library and called for example from C.
Actually Houdini's COPs are very capable, I use them all the time. Also you can define custom procedures/nodes using vex as text or as a separate node interface.
I know Houdini very well, I've been writing plugins to it for years. Vex is capable of handling complex expressions, but it is still limited to predefined 20 or 30 types and you cannot extend it (you can in a hackish way using some C++ interface, but lets assume that this is just too hackish). This also effects the UX of Houdini, you can often see nodes with 30 or 50 inputs that look strange (like the std material definition). If you are able to define custom types, you can collapse related parameters into new types.
I'm not talking COPs or Houdini is something bad. It is one of the few applications that I support with whole heart and I love it. In fact Houdini is a very rare example of really well defined visual DSL.
Luna differs in many ways, the most important are that we've got double representation and Luna is a real programming language, while Houdini provides you limited set of building, yet very powerful blocks. I would however love to see Luna used within Houdini as a plugin, I've been already speaking about it with some folks :)
Keep up the good work!