ISF stands for “Interactive Shader Format”, and is a file format that describes a GLSL fragment shader, as well as how to execute and interact with it. The goal of this file format is to provide a simple and minimal interface for image filters and generative video sources that allows them to be interacted with and reused in a generic and modular fashion. ISF is nothing more than a (slightly modified) GLSL fragment shader with a JSON blob at the beginning that describes how to interact with the shader (how many inputs/uniform variables it has, what their names are, what kind of inputs/variables they are, that sort of thing). ISF isn’t some crazy new groundbreaking technology- it’s just a simple and useful combination of two things that have been around for a while to make a minimal- but highly effective- filter format.
ISF is a very simple file format, and has more inherent limitations than QC/CI/Vuo/FreeFrame. That being said, a tremendous amount is still possible with a multi-pass fragment shader- and the format’s simplicity means that ISF media generally runs faster and has fewer bugs and problems than other formats, while also being faster and easier to put together.
The open-source ISF Editor is distributed with VDMX in the “Extras” folder on the dmg, and VDMX also installs nearly 200 ISF files- both generators and filters- on your system (in /Library/Graphics/ISF) where VDMX and any other software that supports ISF can use them. The ISF Editor also has a built-in installer for a QuickLook plugin that renders thumbnails for ISF files in the Finder. More information about ISF- including our open-source implementation- can be found here: https://github.com/mrRay/ISF_Spec/
Making Video FX and Built-In Image Sources with ISF
The ISF Editor can be used to create new ISF files- as long as there is an “image”-type input named “inputImage”, the ISF file can be used as an image filter. The ISF file can be placed in the “ISF” folder in your VDMX Assets folder, but it’s often more convenient to install them in a more general location where they can be used by other software- /Library/Graphics/ISF and ~/Library/Graphics/ISF are the default locations. Any ISF files in any of these folders will be made available in VDMX (you don’t have to put FX in one folder and sources in another).
Finding and sharing ISF compositions
Visit www.interactiveshaderformat.com to find and share ISF compositions online.