Shader and compositor curve nodes change their inputs even if they are at identity settings. That is because shader and compositor curve nodes evaluate their curve map texture samplers at the normalized input directly, disregarding the fact that the samplers are evaluated using linear interpolation. This causes the output to be slightly different that it should be. This patch remaps the evaluation parameters such that the texture sampler is evaluated at the center of the pixels. Differential Revision: https://developer.blender.org/D15811 Reviewed By: Clement Foucault