API Reference > imodeljs-frontend > Rendering > ScreenSpaceEffectSource > fragment fragment fragment: string The GLSL implementation of the fragment shader. Instead of main, it implements vec4 effectMain() returning the color to be output. effectMain should sample u_diffuse directly using TEXTURE() or TEXTURE_PROJ() instead of texture2D(), texture2DProj(), or texture(); or, if ScreenSpaceEffectSource.sampleSourcePixel is defined, it can use sampleSourcePixel() instead. It should not assign to gl_FragColor. The alpha component of the output color is ignored as there is nothing with which to blend. Defined in core/frontend/src/render/ScreenSpaceEffectBuilder.ts Line 120 Last Updated: 11 June, 2024