.FSH File Extension

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.

NOTE: Fragment shaders differ from vertex shaders (.VSH and .VERT files), which store vertex code required to manipulate the position of the triangle mesh vertices that make up a 3D model.

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.