.FSH File Extension
What is an FSH file?
An FSH file contains fragment shading properties in the OpenGL Shading Language (GLSL). It stores fragment shading code run by a GPU to render 3D graphics with color, shadows, and other effects. FSH files may also be saved as .FRAG files.
GLSL is a high-level shading language utilized by Open Graphics Library OpenGL, which is an application programming interface (API) that renders 2D and 3D graphics. Various applications utilize OpenGL, including Google Earth, Minecraft, and Adobe Photoshop.
FSH files contain data that shades a fragment, which is a pixel in a rasterized triangle that makes up a 3D image. When rendered by the GPU, the code in the FSH file determines the color (includes the saturation, hue, brightness, and contrast) of the pixels in the graphics.
How to open an FSH file
You can open FSH files with the tools included with OpenGL SDK (multiplatform) and Apple Xcode (macOS). You can also open and edit FSH files with source code editors, such as Microsoft Visual Studio Code (multiplatform).
While you can open FSH files with plain text editors, such as Microsoft Notepad (bundled with Windows), Apple TextEdit (bundled with macOS), or gedit (Linux), these editors do not provide helpful editing capabilities (like syntax highlighting) like source code editors.
NOTE: You can also open FSH files with AMD GPU ShaderAnalyzer (Windows) and Apple OpenGL Shader Builder (macOS), but they are discontinued.