Texture sampling is the process of reading colour or data values from a texture image at arbitrary coordinates during rendering, typically involving interpolation between discrete texel values to produce a smooth result. Filtering strategies such as bilinear, trilinear, and anisotropic sampling trade computational cost against visual quality when textures are minified or viewed at oblique angles. Texture sampling is invoked heavily during post-processing passes and volume rendering, where many samples per pixel may be required.