Examples described herein generally relate to modifying operations of a graphics processing unit (GPU) for tracking. An indication of multiple shaders to be executed in rendering an image can be obtained from a command buffer of commands to be provided to the GPU for rendering the image. At least one shader of the multiple shaders can be modified to generate a modified shader that includes a command to log one or more parameters when executing the modified shader. The command buffer can be provided to the GPU for executing the commands for rendering the image including executing the modified shader.